Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
  • G06F13/38—Information transfer, e.g. on bus
  • G06F13/40—Bus structure
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
  • G06F13/38—Information transfer, e.g. on bus
  • G06F13/40—Bus structure
  • G06F13/4063—Device-to-bus coupling
  • G06F13/4068—Electrical coupling
  • G06F13/4072—Drivers or receivers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/1066—Session management
  • H04L65/1101—Session protocols
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/60—Network streaming of media packets
  • H04L65/70—Media network packetisation
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
  • H04L69/22—Parsing or analysis of headers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M1/00—Substation equipment, e.g. for use by subscribers
  • H04M1/72—Mobile telephones; Cordless telephones, i.e. devices for establishing wireless links to base stations without route selection
  • H04M1/724—User interfaces specially adapted for cordless or mobile telephones
  • H04M1/72403—User interfaces specially adapted for cordless or mobile telephones with means for local support of applications that increase the functionality
  • H04M1/72409—User interfaces specially adapted for cordless or mobile telephones with means for local support of applications that increase the functionality by interfacing with external accessories
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M1/00—Substation equipment, e.g. for use by subscribers
  • H04M1/72—Mobile telephones; Cordless telephones, i.e. devices for establishing wireless links to base stations without route selection
  • H04M1/724—User interfaces specially adapted for cordless or mobile telephones
  • H04M1/72403—User interfaces specially adapted for cordless or mobile telephones with means for local support of applications that increase the functionality
  • H04M1/72409—User interfaces specially adapted for cordless or mobile telephones with means for local support of applications that increase the functionality by interfacing with external accessories
  • H04M1/72412—User interfaces specially adapted for cordless or mobile telephones with means for local support of applications that increase the functionality by interfacing with external accessories using two-way short-range wireless interfaces
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
  • Y02D30/00—Reducing energy consumption in communication networks
  • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

• Embodiments of the invention in this disclosure relate to a digital signal protocol and process for communicating or transferring signals between a host device and a client device at high data rates. More specifically, the disclosure relates to a technique for transferring multimedia and other types of digital signals from a host or controller device to a client device for presentation or display to an end user using a low power high data rate transfer mechanism having internal and external device applications.
• video data is typically transferred using current techniques at a rate that could be best termed as slow or medium, being on the order of one to tens of kilobits per second.
• This data is then either buffered or stored in transient or longer-term memory devices, for delayed (later) play out on a desired viewing device.
• images may be transferred "across" or using the Internet using a program resident on a computer having a modem or internet connection device, to receive or transmit data useful in digitally representing an image.
• a similar transfer can take place using wireless devices such as portable computers equipped with wireless modems, or wireless Personal Data Assistants (PDAs), or wireless telephones.
• PDAs Personal Data Assistants
• the data is stored locally in memory elements, circuits, or devices, such as RAM or flash memory, including external storage devices, for playback.
• the playback might begin relatively quickly, or be presented with longer-term delay. That is, in some instances, image presentation allows for a certain degree of real time playback for very small or low resolution images not requiring much data, or using some type of buffering, so that after a small delay, some material is presented while more material is being transferred. Provided there are no interruptions in the transfer link, once the presentation begins the transfer is reasonably transparent to the end user of the viewing device.
• JPEG Joint Photographic Experts Group
• MPEG Motion Picture Experts Group
• a typical computer video resolution in terms of a screen resolution of X by Y pixels typically ranges from as low as 480x640 pixels, through 600x800 to 1024x1024, although a variety of other resolutions are generally possible, either as desired or needed.
• Image presentation is also affected by the image content and the ability of given video controllers to manipulate the image in terms of certain predefined color levels or color depth (bits per pixel used to generate colors) and intensities, and any additional overhead bits being employed.
• bits per pixel used to generate colors
• intensities and any additional overhead bits being employed.
• a typical computer presentation would anticipate anywhere from around 8 to 32, or more, bits per pixel to represent various colors (shades and hues), although other values are encountered.
• a high data transfer rate link is required between presentation elements and the source or host device that is configured to provide such types of data.
• VGA Analog Video Graphics Adapter
• DVI Digital Video Interactive
• GVIF Gigabit Video Interface
• Embodiments for the invention are directed to a Mobile Data Digital Interface (MDDI) for transferring digital data at a high rate between a host device and a client device over a communication path which employs a plurality or series of packet structures linked together to form a communication protocol for communicating a pre-selected set of digital control and presentation data between the host and client devices.
• the signal communications protocol or link layer is used by a physical layer of host or client link controllers.
• At least one link controller residing in the host device is coupled to the client device through the communications path or link, and is configured to generate, transmit, and receive packets forming the communications protocol, and to form digital presentation data into one or more types of data packets.
• the interface provides for bi-directional transfer of information between the host and client, which can reside within a common overall housing or support structure.
• the implementation is generally all digital in nature with the exception of differential drivers and receivers which can be easily implemented on a digital CMOS chip, requires a few as 6 signals, and operates at almost any data rate that is convenient for the system designer.
• the simple physical and link layer protocol makes it easy to integrate, and this simplicity plus a hibernation state enables the portable system to have very low system power consumption.
• the interface will add very little to the cost of a device, will allow for consumption of very little power while able to power displays through the interface using standard battery voltages, and can accommodate devices having a pocket- able form-factor.
• the interface is scalable to support resolutions beyond HDTV, supports simultaneous stereo video and 7.1 audio to a display device, performs conditional updates to any screen region, and supports multiple data types in both directions.
• At least one client link controller is disposed in the client device and is coupled to the host device through the communications path or link.
• the client link controller is also configured to generate, transmit, and receive packets forming the communications protocol, and to form digital presentation data into one or more types of data packets.
• the host or link controller employs a state machine for processing data packets used in commands or certain types of signal preparation and inquiry processing, but can use a slower general purpose processor to manipulate data and some of the less complex packets used in the communication protocol.
• the host controller comprises one or more differential line drivers; while the client receiver comprises one or more differential line receivers coupled to the communication path.
• the packets are grouped together within media frames that are communicated between the host and client devices having a pre-defined fixed length with a pre-determined number of packets having different variable lengths.
• the packets each comprise a packet length field, one or more packet data fields, and a cyclic redundancy check field.
• a Sub- frame Header Packet is transferred or positioned at the beginning of transfers of other packets from the host link controller.
• One or more Video Stream type packets and Audio Stream type packets are used by the communications protocol to transfer video type data and audio type data, respectively, from the host to the client over a forward link for presentation to a client device user.
• One or more Reverse Link Encapsulation type packets are used by the communications protocol to transfer data from the client device to the host link controller. These transfer in some embodiments include the transfer of data from internal controllers having at leas one MDDI device to internal video screens. Other embodiments include transfer to internal sound systems, and transfers from various input devices including joysticks and complex keyboards to internal host devices
• Filler type packets are generated by the host link controller to occupy periods of forward link transmission that do not have data.
• a plurality of other packets are used by the communications protocol to transfer video information. Such packets include Color Map, Bit Block Transfer, Bitmap Area Fill, Bitmap Pattern Fill, and Transparent Color Enable type packets.
• User-Defined Stream type packets are used by the communications protocol to transfer interface-user defined data.
• Keyboard Data and Pointing Device Data type packets are used by the communications protocol to transfer data to or from user input devices associated with said client device.
• a Link Shutdown type packet is used by the communications protocol to terminate the transfer of data in either direction over said communication path.
• the communication path generally comprises or employs a cable having a series of four or more conductors and a shield.
• printed wires or conductors can be used, as desired, with some residing on flexible substrates.
• the host link controller requests display capabilities information from the client device in order to determine what type of data and data rates said client is capable of accommodating through said interface.
• the client link controller communicates display or presentation capabilities to the host link controller using at least one Display Capability type packet.
• Multiple transfer modes are used by the communications protocol with each allowing the transfer of different maximum numbers of bits of data in parallel over a given time period, with each mode selectable by negotiation between the host and client link controllers. These transfer modes are dynamically adjustable during transfer of data, and the same mode need not be used on the reverse link as is used on the forward link.
• the host device comprises a wireless communications device, such as a wireless telephone, a wireless PDA, or a portable computer having a wireless modem disposed therein.
• a typical client device comprises a portable video display such as a micro-display device, and/or a portable audio presentation system.
• the host may use storage means or elements to store presentation or multimedia data to be transferred to be presented to a client device user.
• the host device comprises a controller or communication link control device with drivers as described below residing within a portable electronic device such as a wireless communications device, such as a wireless telephone, a wireless PDA, or a portable computer.
• a typical client device in this configuration comprises a client circuit or integrated circuit or module coupled to the host and residing ihtin the same device, and to an internal video display such as a high resolution screen for a mobile phone, and/or a portable audio presentation system.
• FIG. 1A illustrates a basic environment in which embodiments of the invention might operate including the use of a micro-display device used in conjunction with a portable computer.
• FIG. IB illustrates a basic environment in which embodiments of the invention might operate including the use of a micro-display device and audio presentation elements used in conjunction with a wireless transceiver.
• FIG. 1A illustrates a basic environment in which embodiments of the invention might operate including the use of a micro-display device and audio presentation elements used in conjunction with a wireless transceiver.
• FIG. IC illustrates a basic environment in which embodiments of the invention might operate including the use of a micro-display device used in conjunction with a portable computer.
• FIG. ID illustrates a basic environment in which embodiments of the invention might operate including the use of a micro-display device and audio presentation elements used in conjunction with a wireless transceiver.
• FIG. 2 illustrates the overall concept of a Mobile Digital Data Interface with a host and client interconnection.
• FIG. 3 illustrates the structure of a packet useful for realizing data transfers from a client device to a host device.
• FIG. 4 illustrates the use of an MDDI link controller and the types of signals passed between a host and a client over the physical data link conductors for Type I and Type U interfaces.
• FIG. 5 illustrates the use of an MDDI link controller and the types of signals passed between a host and a client over the physical data link conductors for Types U, II, and IV interfaces.
• FIG. 6 illustrates the structure of frames and sub-frames used to implement the interface protocol.
• FIG. 7 illustrates the general structure of packets used to implement the interface protocol.
• FIG. 8 illustrates the format of a Sub-frame Header Packet.
• FIG. 9 illustrates the format and contents of a Filler Packet.
• FIG. 10 illustrates the format of a Video Stream Packet.
• FIG. 11 illustrates the format and contents for the Video Data Format Descriptor of FIG. 10.
• FIG. 12 illustrates the use of packed and unpacked formats for data.
• FIG. 13 illustrates the format of an Audio Stream Packet.
• FIG. 14 illustrates the use of byte-aligned and packed PCM formats for data
• FIG. 15 illustrates the format of a User-Defined Stream Packet.
• FIG. 16 illustrates the format of a Color Map Packet.
• FIG. 17 illustrates the format of a Reverse Link Encapsulation Packet.
• FIG. 18 illustrates the format of a Display Capability Packet.
• FIG. 19 illustrates the format of a Keyboard Data Packet.
• FIG. 20 illustrates the format of a Pointing Device Data Packet.
• FIG. 21 illustrates the format of a Link Shutdown Packet.
• FIG. 22 illustrates the format of a Display Request and Status Packet.
• FIG. 23 illustrates the format of a Bit Block Transfer Packet.
• FIG. 24 illustrates the format of a Bitmap Area Fill Packet.
• FIG. 25 illustrates the format of a Bitmap Pattern Fill Packet.
• HG. 26 illustrates the format of a Communication Link Data Channel Packet.
• FIG. 27 illustrates the format of a Interface Type Handoff Request Packet.
• FIG. 28 illustrates the format of an Interface Type Acknowledge Packet.
• FIG. 29 illustrates the format of a Perform Type Handoff Packet.
• FIG. 30 illustrates the format of a Forward Audio Channel Enable Packet.
• FIG. 31 illustrates the format of a Reverse Audio Sample Rate Packet.
• FIG. 32 illustrates the format of a Digital Content Protection Overhead Packet.
• FIG. 33 illustrates the format of a Transparent Color Enable Packet.
• FIG. 34 illustrates the format of a Round Trip Delay Measurement Packet.
• FIG. 35 illustrates the timing of events during the Round Trip Delay Measurement Packet.
• FIG. 36 illustrates a sample implementation of a CRC generator and checker useful for implementing the invention.
• FIG. 37A illustrates the timing of CRC signals for the apparatus of FIG. 36 when sending data packets.
• FIG. 37B illustrates the timing of CRC signals for the apparatus of FIG. 36 when receiving data packets.
• FIG. 38 illustrates processing steps for a typical service request with no contention.
• FIG. 39 illustrates processing steps for a typical service request asserted after the link restart sequence has begun, contending with link start.
• FIG. 40 illustrates how a data sequence can be transmitted using DATA-STB encoding.
• FIG. 41 illustrates circuitry useful for generating the DATA and STB signals from input data at the host, and then recovering the data at the client.
• FIG. 42 illustrates drivers and terminating resistors useful for implementing one embodiment.
• FIG. 43 illustrates steps and signal levels employed by a client to secure service from the host and by the host to provide such service.
• FIG. 44 illustrates relative spacing between transitions on the DataO, other data lines (DataX), and the strobe lines (Stb).
• FIG. 45 illustrates the presence of a delay in response that can occur when a host disables the host driver after transferring a packet.
• FIG. 46 illustrates the presence of a delay in response that can occur when a host enables the host driver to transfer a packet.
• FIG. 47 illustrates the relationship at the host receiver input between the timing of the data being transferred and the leading and trailing edges of the strobe pulses.
• FIG. 48 illustrates switching characteristics and corresponding client output delay developed by the reverse data timing.
• FIG. 49 illustrates a high level diagram of signal processing steps and conditions by which synchronization can be implemented using a state machine.
• FIG. 50 illustrates typical amounts of delay encountered for signal processing on the forward and reverse paths in a system employing the MDDI.
• FIG. 51 illustrates marginal round trip delay measurement.
• FIG. 52 illustrates Reverse Link data rate changes.
• FIG. 53 illustrates a graphical representation of values of the Reverse Rate Divisor versus forward link data rate.
• FIGS. 54 A and 54B illustrate steps undertaken in the operation of an interface.
• FIG. 55 illustrates an overview of the interface apparatus processing packets.
• FIG. 56 illustrates the format of a Forward Link Packet
• FIG. 57 illustrates typical values for propagation delay and skew in an Type-I Link interface.
• FIG. 58 illustrates Data, Stb, and Clock Recovery Timing on a Type-I Link for exemplary signal processing through the interface.
• FIG. 59 illustrates typical values for propagation delay and skew in Type-U, Type- ⁇ i or Type-IV Link interfaces.
• FIGS. 60 A, 60B, and 60C illustrate different possibilities for the timing of two data signals and MDDI_Stb with respect to each other, being ideal, early, and late, respectively.
• FIG. 61 illustrates interface pin assignments exemplary connectors used with a Type-JVType-U interfaces. [0095] FIGS.
• FIG. 62A and 62B illustrate possible MDDIJData and MDDI_Stb waveforms for both Type-I and Type-U Interfaces, respectively.
• FIG. 63 illustrates a high level diagram of alternative signal processing steps and conditions by which synchronization can be implemented using a state machine.
• FIG. 64 illustrates exemplary relative timing between a series of clock cycles and the timing of a various reverse link packets bits and divisor values.
• FIG. 65 illustrates exemplary error code transfer processing.
• FIG. 66 illustrates apparatus useful for error code transfer processing.
• FIG. 67 A illustrates error code transfer processing for code overloading.
• FIG. 67B illustrates error code transfer processing for code reception.
• FIG. 68A illustrates processing steps for a host initiated wake-up.
• FIG. 68B illustrates processing steps for a client initiated wake-up.
• FIG. 68C illustrates processing steps for host and client initiated wake-up with contention.
• FIG. 69 illustrates the format of a Request VCP Feature Packet
• FIG. 70 illustrates the format of a VCP Feature Reply Packet
• FIG. 71 illustrates the format of a VCP Feature Reply List
• FIG. 72 illustrates the format of a Set VCP Feature Packet
• FIG. 73 illustrates the format of a Request Valid Parameter Packet
• FIG. 74 illustrates the format of a Valid Parameter Reply Packet
• FIG. 75 illustrates the format of a Alpha-Cursor Image Capability Packet
• FIG. 76 illustrates the format of a Alpha-Cursor Transparency Map Packet
• FIG. 77 illustrates the format of a Alpha-Cursor Image Offset Packet
• FIG. 78 illustrates the format of a Alpha-Cursor Video Stream Packet
• FIG. 79 illustrates the format of a Scaled Video Stream Capability Packet
• FIG. 80 illustrates the format of a Scaled Video Stream Setup Packet
• FIG. 81 illustrates the format of a Scaled Video Stream Acknowledgement Packet
• FIG. 82 illustrates the format of a Scaled Video Stream Packet
• FIG. 83 illustrates the format of a Request Specific Status Packet
• FIG. 84 illustrates the format of a Valid Status Reply List Packet
• FIG. 85 illustrates the format of a Packet Processing Delay Parameters Packet
• FIG. 86 illustrates the format of a Personal Display Capability Packet
• FIG. 87 illustrates the format of a Display Error Report Packet
• FIG. 88 illustrates the format of a Display Identification Packet
• FIG. 89 illustrates the format of a Alternate Display Capability Packet
• FIG. 90 illustrates the format of a Register Access Packet
• FIG. 91 A-91C illustrate use of two display buffers to reduce visible artifacts
• FIG. 92 illustrates two buffers with display refresh faster than image transfer
• FIG. 93 illustrates two buffers with display refresh slower than image transfer
• FIG. 94 illustrates two buffers with display refresh much faster than image transfer
• FIG. 95 illustrates three buffers with display refresh faster than image transfer
• FIG. 96 illustrates three buffers with display refresh slower than image transfer
• FIG. 97 illustrates one buffer with display refresh faster than image transfer
• FIG. 98 illustrates host-client connection via daisy -chain and hub.
• FIG. 99 illustrates client devices connected via a combination of hubs and daisy chains.
• a general intent of the invention is to provide a Mobile Display Digital Interface (MDDI), as discussed below, which results in or provides a cost-effective, low power consumption, transfer mechanism that enables high- or very-high- speed data transfer over a short-range communication link between a host device and a client device, such as a display element, using a "serial" type of data link or channel.
• MDDI Mobile Display Digital Interface
• This mechanism lends itself to implementation with miniature connectors and thin flexible cables which are especially useful in connecting internal (to a housing or support frame) display elements or input devices to a central controller, or external display elements or devices such as wearable micro-displays (goggles or projectors) to portable computers, wireless communication devices, or entertainment devices.
• An advantage of embodiments of the invention is that a technique is provided for data transfer that is low in complexity, low cost, has high reliability, fits well within the environment of use, and is very robust, while remaining very flexible.
• Embodiments of the invention can be used in a variety of situations to communicate or transfer large quantities of data, generally for audio, video, or multimedia applications from a host or source device where such data is generated or stored, to a client display or presentation device at a high rate.
• a typical application which is discussed below, is the transfer of data from either a portable computer or a wireless telephone or modem to a visual display device such as a small video screen or a wearable micro-display appliance, such as in the form of goggles or helmets containing small projection lenses and screens, or from a host to client device within such components. That is, from a processor to an internal screen or other presentation element, as well as from various internal, or external input devices employing a client to an internally located (collocated within same device housing or support structure) host.
• the characteristics or attributes of the MDDI are such that they are independent of specific display technology. This is a highly flexible mechanism for transferring data at a high rate without regards to the internal structure of that data, nor the functional aspects of the data or commands it implements. This allows the timing of data packets being transferred to be adjusted to adapt to the idiosyncrasies of particular client devices, such as for unique display desires for certain devices, or to meet the requirements of combined audio and video for some A-V systems, or for certain input devices such as joysticks, touch pads, and so forth.
• the interface is very display element or client device agnostic, as long as the selected protocol is followed.
• the aggregate serial link data or data rate can vary over several orders of magnitude which allows a communication system or host device designer to optimize the cost, power requirements, client device complexity, and client device update rates.
• the data interface is presented primarily for use in transferring large amounts of high rate data over a "wired" signal link or small cable.
• some applications may take advantage of a wireless link as well, including optical based links, provided it is configured to use the same packet and data structures developed for the interface protocol, and can sustain the desired level of transfer at low enough power consumption or complexity to remain practical.
• FIGS. 1A and IB A typical application can be seen in FIGS. 1A and IB where a portable or laptop computer 100 and wireless telephone or PDA device 102 are shown communicating data with display devices 104 and 106, respectively, along with audio reproduction systems 108 and 112.
• FIG 1A shows potential connections to a larger display or screen 114 or an image projector 116, which are only shown in one figure for clarity, but are connectable to wireless device 102 as well.
• the wireless device can be currently receiving data or have previously stored a certain amount of multimedia type data in a memory element or device for later presentation for viewing and or hearing by an end user of the wireless device.
• Computer 100 Since a typical wireless device is used for voice and simple text communications most of the time, it has a rather small display screen and simple audio system (speakers) for communicating information to the device 102 user.
• Computer 100 has a much larger screen, but still inadequate external sound system, and still falls short of other multimedia presentation devices such as a high definition television, or movie screens. Computer 100 is used for purposes of illustration and other types of processors, interactive video games, or consumer electronics devices can also be used with the invention. Computer 100 can employ, but is not limited to or by, a wireless modem or other built in device for wireless communications, or be connected to such devices using a cable or wireless link, as desired.
• wireless device 102 or computer 100 may also be additional elements connected to or associated with the use of wireless device 102 or computer 100 for presenting an output to another user, or to another device which in turn transfers the signals elsewhere or stores them.
• data may be stored in flash memory, in optical form, for example using a writeable CD media or on magnetic media such as in a magnetic tape recorder and similar devices, for later use.
• external speakers 114 are shown in FIG. la, which could also be accompanied by addition elements such as sub-woofers, or "surround- sound" speakers for front and rear sound projection.
• speakers or earphones 108 are indicated as built-in to the support frame or mechanism of micro-display device 106 of FIG. lb.
• other audio or sound reproduction elements can be used including power amplification or sound shaping devices.
• transfer link 110 is clearly a potential bottleneck in the communication of data as discussed earlier, and is limiting system performance, since current transfer mechanisms do not achieve the high data rates typically desired.
• the data rates can approach rates in excess of 755 Mbps or more.
• images may be presented as part of a multimedia presentation which includes audio data and potentially additional signals dealing with interactive gaming or communications, or various commands, controls, or signals, further increasing the quantity or data and the data rate.
• FIGS. IC and ID Another typical application related to many of the above and other improvements in video screens and other output or input devices can be seen in FIGS. IC and ID where a portable or laptop computer 130 and wireless telephone or PDA device 140 are shown communicating data with "internal" display devices 134 and 144, respectively, along with audio reproduction systems 136 and 146.
• FIGS. IC and ID small cut-away sections of the overall electronic devices or products are used to show the location of one or more internal hosts and controllers in one portion of the device with a generalized communication link, here 138 and 148, respectively, connecting them to the video display elements or screens having the corresponding clients, across a rotating joint of some known type used throughout the electronics industry today.
• a generalized communication link here 138 and 148, respectively, connecting them to the video display elements or screens having the corresponding clients, across a rotating joint of some known type used throughout the electronics industry today.
• a signal protocol and system architecture has been formulated that provides a very high data transfer rate using low power signals.
• the protocol is based on a packet and common frame structure, or structures linked together to form a protocol for communicating a pre-selected set of data or data types along with a command or operational structure imposed on the interface.
• the devices connected by or communicating over the MDDI link are called the host and client, with the client typically being a display device of some type, although other output and input devices are contemplated.
• Data from the host to the display travels in the forward direction (referred to as forward traffic or link), and data from the client to the host travels in the reverse direction (reverse traffic or link), as enabled by the host.
• forward traffic or link Data from the host to the display travels in the forward direction
• reverse traffic or link reverse traffic or link
• FIG. 2 a host 202 is connected to a client 204 using a bi-directional communication channel 206 which is illustrated as comprising a forward link 208 and a reverse link 210.
• these channels are formed by a common set of conductors whose data transfer is effectively switched between the forward or reverse link operations. This allows for greatly reduced numbers of conductors, immediately addressing one of the many problems faced with current approaches to high speed data transfer in low power environments such as for mobile electronic devices.
• host 202 comprises one of several types of devices that can benefit from using the present invention.
• host 202 could be a portable computer in the form of a handheld, laptop, or similar mobile computing device, it could be a Personal Data Assistant (PDA), a paging device, or one of many wireless telephones or modems.
• PDA Personal Data Assistant
• host 202 could be a portable entertainment or presentation device such as a portable DVD or CD player, or a game playing device.
• the host can reside as a host device or control element in a variety of other widely used or planned commercial products for which a high speed communication link is desired with a client.
• a host could be used to transfer data at high rates from a video recording device to a storage based client for improved response, or to a high resolution larger screen for presentations.
• An appliance such as a refrigerator that incorporates an onboard inventory or computing system and/or Bluetooth connections to other household devices, can have improved display capabilities when operating in an internet or Bluetooth connected mode, or have reduced wiring needs for in-the-door displays (a client) and keypads or scanners (client) while the electronic computer or control systems (host) reside elsewhere in the cabinet.
• a client keypads or scanners
• host electronic computer or control systems
• client 204 could comprise a variety of devices useful for presenting information to an end user, or presenting information from a user to the host.
• Another example would be the use of touch pads or sensitive devices, voice recognition input devices, security scanners and so forth that may want to transfer a significant amount of information from the user with little actual "input" other than touch or sound from the user.
• the present invention is not limited to these devices, there being many other devices on the market, and proposed for use, that are intended to provide end users with high quality images and sound, either in terms of storage and transport or in terms of presentation at playback.
• the present invention is useful in increasing the data throughput between various elements or devices to accommodate the high data rates needed for realizing the desired user experience.
• the inventive MDD Interface and communication signal protocol may be used to simplify the interconnect between a host processor and a display within a device (internal mode) to reduce the cost of these connections and improve reliability, not just for external elements (external mode).
• the aggregate serial link data rate on each signal pair used by this interface structure can vary over many orders of magnitude, which allows a system or device designer to easily optimize cost, power, implementation complexity, and the display update rate.
• the attributes of MDDI are independent of display technology.
• the timing of data packets transferred through the interface can be easily adjusted to adapt to idiosyncrasies of particular display devices or combined timing requirements of audio-video systems. While this allows the system to have the smallest power consumption possible, it is not a requirement of the display to have a frame buffer in order to use MDDI.
• the MDD Interface is contemplated as addressing five or more somewhat distinct physical types of interfaces found in the communications and computer industries. These are labeled simply as Type-I, Type-U, Type-IU, Type-IV and Type-U, although other labels or designations may be applied by those skilled in the art depending upon the application they are used for.
• the Type-I interface is configured as a 6- wire (conductor) interface which makes it suitable for mobile or wireless telephones, PDAs, e-Books, electronic games, and portable media players, such as CD players, or MP3 players, and similar devices or devices used on similar types of electronic consumer technology.
• a Type-U interface is configured as an 8-wire (conductor) interface which is more suitable for laptop, notebook, or desktop personal computers and similar devices or applications, that do not require the display to be updated rapidly and do not have a built-in MDDI link controller.
• This interface type is also distinguishable by the use of an additional two-wire Universal Serial Bus (USB) interface, which is extremely useful in accommodating existing operating systems or software support found on most personal computers.
• USB Universal Serial Bus
• Type-U interfaces can also be used in a USB-only mode where the display simply has a USB connector that connects to a standard USB port on a computer or similar device, for example a consumer electronics device equipped with such a port, such as digital cameras or video players.
• Type-U, Type-UI, and Type-IV interfaces are suitable for high performance clients or devices and use larger more complex cabling with additional twisted-pair type conductors to provide the appropriate shielding and low loss transfers for data signals.
• the Type-I interface passes signals which can comprise display, audio, control, and limited signaling information, and is typically used for mobile clients or client devices that do not require high-resolution full-rate video data.
• a Type-I interface can easily support SVGA resolution at 30 fps plus 5.1 channel audio, and in a minimum configuration might use only three wire pairs total, two pairs for data transmission and one pair for power transfer.
• This type of interface is primarily intended for devices, such as mobile wireless devices, where a USB host is typically not available within the such device for connection and transfer of signals. Li this configuration, the mobile wireless device is a MDDI host device, and acts as the "master" that controls the communication link from the host, which generally sends data to the client (forward traffic or link) for presentation, display or playback.
• a host enables receipt of communication data at the host from the client (reverse traffic or link) by sending a special command or packet type to the client that allows it to take over the bus (link) for a specified duration and send data to the host as reverse packets.
• a type of packet referred to as an encapsulation packet (discussed below) is used to accommodate the transfer of reverse packets over the transfer link, creating the reverse link.
• the time interval allocated for the host to poll the client for data is pre-determined by the host, and is based on the requirements of each specified application. This type of half-duplex bi-directional data transfer is especially advantageous where a USB port is not available for transfer of information or data from the client.
• High-performance displays capable of HDTV type or similar high resolutions require around 1.5 Gbps rate data streams in order to support full-motion video.
• the Type- U interface supports high data rates by transmitting 2 bits in parallel, the Type-UI by transmitting 4 bits in parallel, and the Type-IV interface transfers 8 bits in parallel.
• Type-U and Type-UI use the same cable and connector as Type-I but can operate at twice and four times the data rate to support higher-performance video applications on portable devices.
• Type- IV is suited for very high performance clients or displays and requires a slightly larger cable that contains additional twisted-pair data signals.
• the protocol used by the MDDI allows each Type-I,- ⁇ , -Ul, or -TV host to generally communicate with any Type-I, -U, -Ul, or -IV client by negotiating what is the highest data rate possible that can be used.
• the capabilities or available features of what can be referred to as the least capable device is used to set the performance of the link.
• the host and client are both capable using Type-U, Type-UI, or Type-IV interfaces, both begin operation as a Type-I interface.
• the host determines the capability of the target client, and negotiates a hand-off or reconfiguration operation to either Type-U, Type-UI, or Type-IV mode, as appropriate for the particular application.
• the host may use the proper link-layer protocol (discussed further below) and step down or again reconfigure operation at generally any time to a slower mode to save power or to step up to a faster mode to support higher speed transfers, such as for higher resolution display content.
• a host may change interface types when the system switches from a power source such as a battery to AC power, or when the source of the display media switches to a lower or higher resolution format, or a combination of these or other conditions or events may be considered as a basis for changing an interface type, or transfer mode.
• a system can communicate data using one mode in one direction and another mode in another direction.
• a Type IV interface mode could be used to transfer data to a display at a high rate
• a Type I or Type U mode is used when transferring data to a host device from peripheral devices such as a keyboard or a pointing device.
• hosts and clients may communicate outgoing data at different rates.
• An external mode describes the use of MDDI to connect a host in one device to a client outside of that device that is up to about 2 meters from the host. In this situation, the host may also send power to the external client so that both devices can easily operate in a mobile environment.
• An internal mode describes when the host is connected to a client contained inside the same device, such as within a common housing or support frame or structure of some kind.
• An example would be applications within a wireless phone or other wireless device, or a portable computer or gaming device where the client is a display or display driver and the host is a central controller, graphics engine, or CPU element. Since a client is located much closer to the host in internal mode applications as opposed to external mode applications, there are generally no requirements discussed for the power connection to the client in such configurations.
• FIGS. 4 and 5 The general disposition of a device or link controller for establishing communications between host and client devices is shown in FIGS. 4 and 5.
• a MDDI link controller 402 and 502 is shown installed in a host device 202 and a MDDI link controller 404 and 504 is shown installed in a client device 204.
• host 202 is connected to a client 204 using a bi-directional communication channel 406 comprising a series of conductors.
• both the host and client link controllers can be manufactured as an integrated circuit using a single circuit design that can be set, adjusted or programmed to respond as either a host controller (driver) or a client controller (receiver). This provides for lower costs due to larger scale manufacturing of a single circuit device.
• a MDDI link controller 502 is shown installed in a host device 202' and a MDDI link controller 504 is shown installed in a client device 204'.
• host 202' is connected to a client 204' using a bi-directional communication channel 506 comprising a series of conductors.
• both the host and client link controllers can be manufactured using a single circuit design.
• FIGS. 4 and 5 Signals passed between a host and a client, such as a display device, over the MDDI link, or the physical conductors used, are also illustrated in FIGS. 4 and 5.
• the primary path or mechanism for transferring data through the MDDI uses data signals labeled as MDDI_DataO+/- and MDDI_Stb+/-.
• MDDI_DataO+/- and MDDI_Stb+/- data signals labeled as MDDI_DataO+/- and MDDI_Stb+/-.
• Each of these are low voltage data signals that are transferred over a differential pair of wires in a cable.
• the host drives the MDDI_Stb signals to the client display.
• the host is the master or controller of the data link.
• the MDDIJDataO and MDDI-Stb signal paths are operated in a differential mode to maximize noise immunity.
• the data rate for signals on these lines is determined by the rate of the clock sent by the host, and is variable over a range of about 1 kbps up to 400 Mbps or more.
• the Type-U interface contains one additional data pair or conductors or paths beyond that of the Type-I, referred to as MDDI_Datal+/-.
• the Type-IH interface contains two additional data pairs or signal paths beyond that of the Type-U interface referred to as MDDI_Data2+/-, and MDDI_Data3+/-.
• the Type-IV interface contains four more data pairs or signal paths beyond that of the Type-UI interface referred to as: MDDI_data4+/-, MDDI_Data5+/-, MDDI_Data6+/-, and MDDI_Data7+/-, respectively.
• a host can send power to the client or display using the wire- pair or signals designated as MDD Pwr and MDDI_Gnd.
• power transfer can also be accommodated, if desired, in some configurations on the MDDI_data4+/-, MDDI_Data5+/-, MDDI_Data6+/-, or MDDI_Data7+/- conductors when an interface "Type" is being used that employs fewer conductors than are available or present for the other modes.
• MDDI Pwr/Gnd connections for transfer from the host are provided generally for external modes. Internal applications or modes of operation generally have clients that draw power directly from other internal resources, and do not use MDDI to control power distribution, as would be apparent to one skilled in the art, so such distribution is not discussed in further detail here. However, it is certainly possible to allow power to be distributed through the MDDI interface to allow for certain kinds of power control, synchronization, or interconnection convenience, for example, as would be understood by one skilled in the art.
• Cabling generally used to implement the above structure and operation is nominally on the order of 1.5 meters in length, generally 2 meters or less, and contains three twisted pairs of conductors, each in turn being multi-strand 30 AWG wire.
• a foil shield covering is wrapped or otherwise formed above the three twisted pairs, as an additional drain wire.
• the twisted pairs and shield drain conductor terminate in the display connector with the shield connected to the shield for the display (client), and there is an insulating layer, covering the entire cable, as would be well known in the art.
• the wires are paired as: MDDI_Gnd with MDDI_Pwr; MDDI_Stb+ with MDDI_Stb-; MDDI_Data0+ with MDDI_Data0-; MDDI_Datal+ with MDDI_Datal-; and so forth.
• the Mobile Digital Data Interface provides support for a variety of clients and display information, audio transducers, keyboards, pointing devices, and many other input or output devices that might be integrated into or working in concert with a mobile display device, along with control information, and combinations thereof.
• the MDD interface is designed to be able to accommodate a variety of potential types of streams of data traversing between the host and client in either the forward or reverse link directions using a minimum number of cables or conductors. Both isochronous streams and asynchronous stream (updates) are supported.
• the interface is not fixed but extensible so that it can support the transfer of a variety of information "types" which includes user-defined data, for future system flexibility.
• data to be accommodated are: full-motion video, either in the form of full or partial screen bitmap fields or compressed video; static bitmaps at low rates to conserve power and reduce implementation costs; PCM or compressed audio data at a variety of resolutions or rates; pointing device position and selection, and user-definable data for capabilities yet to be defined.
• Such data may also be transferred along with control or status information to detect device capability or set operating parameters.
• Embodiments of the invention advance the art for use in data transfers that include, but are not limited to: watching a movie (video display and audio); using a personal computer with limited personal viewing (graphics display, sometimes combined with video and audio); playing a video game on a PC, console, or personal device (motion graphics display, or synthetic video and audio); "surfing" the Internet, using devices in the form of a video phone (bi-directional low-rate video and audio), a camera for still digital pictures, or a camcorder for capturing digital video images; using a phone or PDA docked with a projector to give a presentation or docked with a desktop docking station connected to a video monitor, keyboard, and mouse; and for productivity enhancement or entertainment use with cell phones, smart phones, or PDAs, including wireless pointing devices and keyboard data.
• a movie video display and audio
• a personal computer with limited personal viewing (graphics display, sometimes combined with video and audio)
• playing a video game on a PC, console, or personal device motion graphics display
• the mobile data interface as discussed below is presented in terms of providing large amounts of A-V type data over a communication or transfer link which is generally configured as a wire-line or cable type link.
• a communication or transfer link which is generally configured as a wire-line or cable type link.
• the signal structure, protocols, timing, or transfer mechanism could be adjusted to provide a link in the form of an optical or wireless media, if it can sustain the desired level of data transfer.
• the MDD interface signals use a concept known as the Common Frame (CF) for the basic signal protocol or structure.
• CF Common Frame
• the idea behind using of a Common Frame is to provide a synchronization pulse for simultaneous isochronous data streams.
• a client device can use this common frame rate as a time reference.
• a low CF rate increases channel efficiency by decreasing overhead to transmit the sub-frame header.
• a high CF rate decreases the latency, and allows a smaller elastic data buffer for audio samples.
• the CF rate of the present inventive interface is dynamically programmable and may be set at one of many values that are appropriate for the isochronous streams used in a particular application. That is, the CF value is selected to best suit the given client and host configuration, as desired.
• Fractional counts of bytes per common frame are easily obtained using a simple programmable M/N counter structure. For example, a count of 26-2/3 bytes per CF is implemented by transferring 2 frames of 27 bytes each followed by one frame of 26 bytes. A smaller CF rate may be selected to produce an integer number of bytes per CF.
• a simple M/N counter in hardware should require less area within an integrated circuit chip or electronic module used to implement part or all of embodiments of the invention than the area needed for a larger audio sample FIFO buffer.
• An exemplary application that illustrates the impact of different data transfer rates and data types is a Karaoke system.
• Karaoke a system where an end user, or users, sings along with a music video program. Lyrics of the song are displayed somewhere on, typically at the bottom of, a screen so the user knows the words to be sung, and roughly the timing of the song.
• This application requires a video display with infrequent graphics updates, and mixing of the user's voice, or voices, with a stereo audio stream.
• each CF will consist of: 92,160 bytes of video content and 588 bytes of audio content (based on 147 16-bit samples, in stereo) over the forward link to the client display device, and an average of 26.67 (26-2/3) bytes of voice are sent back from a microphone to the mobile Karaoke machine.
• Asynchronous packets are sent between the host and the display, possibly head mounted. This includes at most 768 bytes of graphics data (quarter-screen height), and less than about 200 bytes (several) bytes for miscellaneous control and status commands.
• Table V shows how data is allocated within a Common Frame for the Karaoke example.
• the total rate being used is selected to be about 225 Mbps.
• a slightly higher rate of 226 Mbps allows about another 400 bytes of data per sub-frame to be transferred which allows the use of occasional control and status messages.
• Data transferred using the MDD interface high-speed serial data signals consists of a stream of time-multiplexed packets that are linked one after the other. Even when a transmitting device has no data to send, a MDDI link controller generally automatically sends filler packets, thus, maintaining a stream of packets.
• the use of a simple packet structure ensures reliable isochronous timing for video and audio signals or data streams.
• Groups of packets are contained within signal elements or structures referred to as sub-frames, and groups of sub-frames are contained within signal elements or structures referred to as a media-frame.
• a sub-frame contains one or more packets, depending on their respective size and data transfer uses, and a media-frame contains one more sub- frames.
• the largest sub-frame provided by the protocol employed by the embodiments presented here is on the order of 232-1 or 4,294,967,295 bytes, and the largest media-frame size then becomes on the order of 216-1 or 65,535 sub-frames.
• a special header packet contains a unique identifier that appears at the beginning of each sub-frame, as is discussed below. That identifier is also used for acquiring the frame timing at the client device when communication between the host and client is initiated. Link timing acquisition is discussed in more detail below.
• a display screen is updated once per media-frame when full-motion video is being displayed.
• the display frame rate is the same as the media-frame rate.
• the link protocol supports full-motion video over an entire display, or just a small region of full- motion video content surrounded by a static image, depending on the desired application. In some low-power mobile applications, such as viewing web pages or email, the display screen may only need to be updated occasionally. In those situations, it is advantageous to transmit a single sub-frame and then shut down or inactivate the link to minimize power consumption.
• the interface also supports effects such as stereo vision, and handles graphics primitives.
• Sub-frames allow a system to enable the transmission of high-priority packets on a periodic basis. This allows simultaneous isochronous streams to co-exist with a minimal amount of data buffering. This is one advantage embodiments provide to the display process, allowing multiple data streams (high speed communication of video, voice, control, status, pointing device data, etc.) to essentially share a common channel. It transfers information using relatively few signals. It also enables display-technology- specific actions to exist, such as horizontal sync pulses and blanking intervals for a CRT monitor.
• the MDDI link controller shown in FIGS. 4 and 5 is manufactured or assembled to be a completely digital implementation with the exception of the differential line receivers which are used to receive MDDI data and strobe signals.
• the differential line drivers and receivers can be implemented in the same digital integrated circuits with the link controller, such as when making a CMOS type IC.
• No analog functions or phase lock loops (PLLs) are required for bit recovery or to implement the hardware for the link controller.
• the host and client link controllers contain very similar functions, with the exception of the client interface which contains a state machine for link synchronization. Therefore, the embodiments of the invention allow the practical advantage of being able to create a single controller design or circuit that can be configured as either a host or client, which can reduce manufacturing costs for the link controllers, as a whole.
• FIG. 6 The signal protocol or frame structure used to implement the forward link communication for packet transfer is illustrated in FIG. 6.
• information or digital data is grouped into elements known as packets. Multiple packets are in turn grouped together to form what are referred to as a "sub-frame,” and multiple sub-frames are in turn grouped together to form a "media" frame.
• each sub-frame begins with a specially predefined packet referred to as a Sub-frame Header Packet (SHP).
• SHP Sub-frame Header Packet
• the host device selects the data rate to be used for a given transfer. This rate can be changed dynamically by the host device based on both the maximum transfer capability of the host, or the data being retrieved from a source by the host, and the maximum capability of the client, or other device the data is being transferred to.
• a recipient client device designed for, or capable of, working with the MDDI or inventive signal protocol is able to be queried by the host to determine the maximum, or current maximum, data transfer rate it can use, or a default slower minimum rate may be used, as well as useable data types and features supported. This information could be transferred using a Display Capability Packet (DCP), as discussed further below.
• DCP Display Capability Packet
• the client display device is capable of transferring data or communicating with other devices using the interface at a pre-selected minimum data rate or within a minimum data rate range, and the host will perform a query using a data rate within this range to determine the full capabilities of the client devices.
• the host sends filler packets when there are no (more) data packets to be transferred in the present sub-frame, or when the host cannot transfer at a rate sufficient to keep pace with the data transmission rate chosen for the forward link. Since each sub-frame begins with a sub-frame header packet, the end of the previous sub-frame contains a packet (most likely a filler packet) the exactly fills the previous sub-frame. In the case of a lack of room for data bearing packets per se, a filler packet will most likely be the last packet in a sub- frame, or at the end of a next previous sub-frame and before a sub-frame header packet.
• sub-frame transmission has two modes.
• One mode is a periodic sub-frame mode, or periodic timing epochs, used to transmit live video and audio streams.
• the Sub-frame length is defined as being non-zero.
• the second mode is an asynchronous or non-periodic mode in which frames are used to provide bitmap data to a client only when new information is available. This mode is defined by setting the sub-frame length to zero in the Sub-frame Header Packet.
• sub-frame packet reception may commence when the display has synchronized to the forward link frame structure. This corresponds to the "in sync" states defined according to the state diagram discussed below with respect to FIG. 49 or FIG. 63.
• reception commences after the first Sub-frame Header packet is received.
• each packet type denotes a pre-defined packet structure for a given packet which is used in manipulating the packets and data being transferred.
• the packets may have pre-selected lengths or have variable or dynamically changeable lengths depending on their respective functions.
• the packets could also bear differing names, although the same function is still realized, as can occur when protocols are changed during acceptance into a standard.
• the bytes or byte values used in the various packets are configured as multi-bit (8- or 16-bit) unsigned integers.
• a summary of the packets being employed along with their "type" designations, listed in type order, is shown in Tables VI-1 through VI-4.
• Each table represents a general "type" of packet within the overall packet structure for ease in illustration and understanding. There is no limitation or other impact implied or being expressed for the invention by these groupings, and the packets can be organized in many other fashions as desired. The direction in which transfer of a packet is considered valid is also noted.
• Packets have a common basic structure or overall set of minimum fields comprising a Packet Length field, a Packet Type field, Data Bytes field(s), and a CRC field, which is illustrated in FIG. 7.
• the Packet Length field contains information, in the form of a multi-bit or -byte value, that specifies the total number of bits in the packet, or its length between the packet length field and the CRC field.
• the packet length field contains a 16-bit or 2-byte wide, unsigned integer, that specifies the packet length.
• the Packet Type field is another multi-bit field which designates the type of information that is contained within the packet.
• this is an 16- bit or 2-byte wide value, in the form of an 16-bit unsigned integer, and specifies such data types as display capabilities, handoff, video or audio streams, status, and so forth.
• a third field is the Data Bytes field, which contains the bits or data being transferred or sent between the host and client devices as part of that packet.
• the format of the data is defined specifically for each packet type according to the specific type of data being transferred, and may be separated into a series of additional fields, each with its own format requirements. That is, each packet type will have a defined format for this portion or field.
• the last field is the CRC field which contains the results of a 16-bit cyclic redundancy check calculated over the Data Bytes, Packet Type, and Packet Length fields, which is used to confirm the integrity of the information in the packet. In other words, calculated over the entire packet except for the CRC field itself.
• the client generally keeps a total count of the CRC errors detected, and reports this count back to the host in the Display Request and Status Packet (see further below).
• these field widths and organization are designed to keep 2-byte fields aligned on an even byte boundary, and 4-byte fields aligned on 4-byte boundaries. This allows packet structures to be easily built in a main memory space of, or associated with, a host and a client without violating the data-type alignment rules encountered for most or typically used processors or control circuits.
• LSB Least Significant Bit
• MSB Most Significant Bit
• Parameters that are more than one byte in length are transmitted using the least significant byte first, which results in the same bit transmission pattern being used for a parameter greater than 8 bits in length, as is used for a shorter parameter where the LSB is transmitted first.
• the data fields of each packet are generally transmitted in the order that they are defined in the subsequent sections below, with the first field listed being transmitted first, and the last field described being transmitted last.
• the data on the MDDI_Data0 signal path is aligned with bit '0' of bytes transmitted on the interface in any of the modes, Type-I, Type- ⁇ , Type-UI, or Type-TV.
• the data for arrays of pixels are transmitted by rows first, then columns, as is traditionally done in the electronics arts.
• all pixels that appear in the same row in a bit map are transmitted in order with the left-most pixel transmitted first and the right-most pixel transmitted last.
• the next pixel in the sequence is the left-most pixel of the following row.
• Rows of pixels are generally transmitted in order from top to bottom for most displays, although other configurations can be accommodated as needed.
• a display window is the visible portion of a bitmap, the portion of the pixels in the bitmap that can be seen by the user on the physical display medium.
• the display window and the bitmap are the same size.
• the upper-left corner of a display window always displays bitmap pixel location 0,0.
• the width of the display window corresponds to the X axis of the bitmap, and the display window width shall be less than or equal to the width of the corresponding bitmap.
• the height of the window corresponds to the Y axis of the bitmap, and the display window height shall be less than or equal to the height of the corresponding bitmap.
• the display window itself is not addressable in the protocol because it is only defined as the visible portion of a bitmap. The relationship between a bitmap and display window is illustrated in .
• the Sub-Frame Header packet is the first packet of every sub-frame, and has a basic structure as illustrated in FIG. 8.
• the Sub-Frame Header Packet is used for host-client synchronization, every host should be able to generate this packet, while every client should be able to receive and interpret this packet.
• this type of packet is structured to have Packet Length, Packet Type, Unique Word, Reserved 1, Sub-Frame Length, Protocol Version, Sub-Frame Count, and Media-frame Count fields, generally in that order.
• this type of packet is generally identified as a Type 15359 (0x3bff hexadecimal) packet and uses a pre-selected fixed length of 20 bytes, not including the packet length field.
• the Packet Type field and the Unique Word field each use a 2 byte value (16-bit unsigned integer).
• the 4-byte combination of these two fields together forms a 32-bit unique word with good autocorrelation.
• the actual unique word is 0x005a3bff, where the lower 16 bits are transmitted first as the Packet Type, and the most significant 16 bits are transmitted afterward.
• the Reserved 1 field contains 2 bytes that is reserved space for future use, and is generally configured at this point with all bits set to zero. A purpose of this field is to cause subsequent 2 byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address.
• the least significant byte is reserved to indicate that the host is capable of addressing multiple client devices.
• a value of zero is reserved to indicate that the host is capable of operating only with a single client device.
• the Sub-frame Length field contains 4 bytes of information or values that specifies the number of bytes per sub-frame.
• the length of this field may be set equal to zero to indicate that only one sub-frame will be transmitted by the host before the link is shut down into an idle state.
• the value in this field can be dynamically changed "on- the-fly" when transitioning from one sub-frame to the next. This capability is useful in order to make minor timing adjustments in the sync pulses for accommodating isochronous data streams. If the CRC of the Sub-frame Header packet is not valid then the link controller should use the Sub-frame Length of the previous known-good Sub-frame Header packet to estimate the length of the current sub-frame.
• the Protocol Version field contains 2 bytes that specify the protocol version used by the host.
• the Protocol Version field is set to '0' to specify the first or current version of the protocol as being used. This value will change over time as new versions are created.
• the Sub-frame Count field contains 2 bytes that specify a sequence number that indicates the number of sub-frames that have been transmitted since the beginning of the media-frame.
• the first sub-frame of the media-frame has a Sub-frame Count of zero.
• the last sub-frame of the media-frame has a value of n-1, where n is the number of sub-frames per media- frame. Note that if the Sub-frame Length is set equal to zero (indicating a non-periodic sub-frame) then the Sub-frame count must also be set equal to zero.
• the Media-frame Count field contains 4 bytes (32-bit unsigned integer) that specify a sequence number that indicates the number of media-frames that have been transmitted since the beginning of the present media item or data being transferred.
• the first media- frame of a media item has a Media-frame Count of zero.
• the Media-frame Count value may be reset generally at any time by the Host to suit the needs of an end application.
• a filler packet is a packet that is transferred to, or from, a client device when no other information is available to be sent on either the forward or reverse link. It is recommended that filler packets have a minimum length in order to allow maximum flexibility in sending other packets when required.
• a link controller sets the size of the filler packet to fill the remaining space to maintain packet integrity.
• the Filler Packet is useful to maintain timing on the link when the host or client have no information to send or exchange. Every host and client needs to be able to send and receive this packet to make effective use of the interface.
• FIG. 9 The format and contents of a Filler Packet are shown in FIG. 9.
• this type of packet is structured to have Packet Length, Packet Type, Filler Bytes, and CRC fields.
• this type of packet is generally identified as a Type 0, which is indicated in the 2-byte Type field.
• the bits or bytes in the Filler Bytes field comprise a variable number of all zero bit values to allow the filler packet to be the desired length.
• the smallest filler packet contains no bytes in this field. That is, the packet consists of only the packet length, packet type, and CRC, and in one embodiment uses a pre-selected fixed length of 6 bytes or a Packet Length value of 4.
• the CRC value is determined for all bytes in the packet including the Packet Length, which may be excluded in some other packet types.
• Video Stream Packets carry video data to update typically rectangular regions of a display device. The size of this region may be as small as a single pixel or as large as the entire display. There may be an almost unlimited number of streams displayed simultaneously, limited by system resources, because all context required to display a stream is contained within the Video Stream Packet.
• the format of one embodiment of the Video Stream Packet (Video Data Format Descriptor) is shown in FIG. 10. As seen in FIG.
• this type of packet is structured to have Packet Length (2 bytes), Packet Type, bClient ID, Video Data Descriptor, Pixel Display Attributes, X Left Edge, Y Top Edge, X Right Edge, Y Bottom Edge, X and Y Start, Pixel Count, Parameter CRC, Pixel Data, and CRC fields.
• This type of packet is generally identified as a Type 16, which is indicated in the 2-byte Type field.
• a Client indicates an ability to receive a Video Stream Packet using RGB, Monochrome, and Y Cr Cb Capability fields of the Display Capability Packet.
• the bClient ID field contains 2 bytes of information that are reserved for a Client ID. Since this is a newly developed communications protocol actual client IDs are not yet known or sufficiently communicable. Therefore, the bits in this field are generally set equal to zero until such ID values are known, at which time the ID values can be inserted or used, as would be apparent to those skilled in the art.
• Each Video Stream Packet generally must contain an integer number of pixels, even though it might not contain an integer number of rows of pixels. This is important if pixels are more than one byte each, or if they are in a packed format as shown in FIG. 12.
• FIGS. 11 a- lid The format and contents employed for realizing the operation of an exemplary Video Data Descriptor field, as mentioned above, are shown in FIGS. 11 a- lid.
• the Video Data Format Descriptor field contains 2 bytes in the form of a 16-bit unsigned integer that specifies the format of each pixel in the Pixel Data in the present stream in the present packet. It is possible that different Video Stream packets may use different pixel data formats, that is, use a different value in the Video Data Format Descriptor, and similarly, a stream (region of the display) may change its data format on- the-fly.
• the pixel data format should comply with at least one of the valid formats for the client as defined in the Display Capability Packet.
• the Video Data Format Descriptor defines the pixel format for the present packet only which does not imply that a constant format will continue to be used for the lifetime of a particular video stream.
• FIGS, lla through lid illustrate how the Video Data Format Descriptor is coded.
• the video data when bits [15:13] are equal to '000', as shown in FIG. lla, then the video data consists of an array of monochrome pixels where the number of bits per pixel is defined by bits 3 through 0 of the Video Data Format Descriptor word. Bits 11 through 4 are generally reserved for future use or applications and are set to zero in this situation.
• bits [15:13] are instead equal to '001', as shown in FIG. lib, then the video data consists of an array of color pixels that each specify a color through a color map (palette).
• bits 5 through 0 of the Video Data Format Descriptor word define the number of bits per pixel, and bits 11 through 6 are generally reserved for future use or applications and set equal to zero.
• bits [15:13] are instead equal to '010', as shown in FIG. lie, then the video data consists of an array of color pixels where the number of bits per pixel of red is defined by bits 11 through 8, the number of bits per pixel of green is defined by bits 7 through 4, and the number of bits per pixel of blue is defined by bits 3 through 0.
• the total number of bits in each pixel is the sum of the number of bits used for red, green, and blue.
• the video data consists of an array of video data in 4:2:2 YCbCr format with luminance and chrominance information, where the number of bits per pixel of luminance (Y) is defined by bits 11 through 8, the number of bits of the Cb component is defined by bits 7 through 4, and the number of bits of the Cr component is defined by bits 3 through 0.
• the total number of bits in each pixel is the sum of the number of bits used for red, green, and blue.
• the Cb and Cr components are sent at half the rate as Y.
• the video samples in the Pixel Data portion of this packet are organized as follows: Cbn, Yn, Crn, Yn+1, Cbn+2, Yn+2, Crn+2, Yn+3, ... where Cbn and Crn are associated with Yn and Yn+1, and Cbn+2 and Crn+2 are associated with Yn+2 and Yn+3, and so on.
• Yn, Yn+1, Yn+2 and Yn+3 are luminance values of four consecutive pixels in a single row from left to right.
• the ordering of the color components is typically chosen to be in the same format as the UYVY FOURCC format used by Microsoft Corporation in its software, although the invention is not limited to this format. If there are an odd number of pixels in a row (X Right Edge - X Left Edge + 1) in the window referenced by the Video Stream Packet then the Y value corresponding to the last pixel in each row will be followed by the Cb value of the first pixel of the next row, and a Cr value is not sent for the last pixel in the row.
• pixels in a packet should contain an even number of pixels. It may contain an odd or even number of pixels in the case where the last pixel of the Pixel Data corresponds to the last pixel of a row in the window specified in the Video Stream Packet header, i.e. when the X location of the last pixel in the Pixel Data is equal to X Right Edge.
• the video data consists of an array of Bayer pixels where the number of bits per pixel is defined by bits 3 through 0 of the Video Data Format Descriptor word.
• the Pixel Pattern is defined by bits 5 and 4 as shown in Error! Reference source not found. (Bayer).
• the order of pixel data may be horizontal or vertical and the pixels in rows or columns may be sent in forward or backward order and is defined by bits 8 through 6 as shown in Error! Reference source not found.. Bits 11 through 9 should be set to zero.
• bit 12 which is designated as "P" specifies whether or not the Pixel Data samples are packed, or byte-aligned pixel data.
• a value of '0' in this field indicates that each pixel in the Pixel Data field is byte-aligned with an MDD interface byte boundary.
• a value of T indicates that each pixel and each color within each pixel in the Pixel Data is packed up against the previous pixel or color within a pixel leaving no unused bits.
• the first pixel in the first video stream packet of a media frame for a particular display window will go into the upper left corner of the stream window defined by an X Left Edge and a Y Top Edge, and the next pixel received is placed in the next pixel location in the same row, and so on.
• the X start value will usually be equal to X Left Edge
• Y start value will usually be equal to Y Top Edge.
• the X and Y start values will usually be set to the pixel location in the screen window that would normally follow after the last pixel sent in the Video Stream Packet that was transmitted in the previous sub- frame.
• the audio stream packets carry audio data to be played through the audio system of the client, or for a stand alone audio presentation device.
• Different audio data streams may be allocated for separate audio channels in a sound system, for example: left-front, right- front, center, left-rear, and right-rear, depending on the type of audio system being used.
• a full complement of audio channels is provided for headsets that contain enhanced spatial- acoustic signal processing.
• a Client indicates an ability to receive an Audio Stream Packet using the Audio Channel Capability and Audio Sample Rate fields of the Display Capability Packet.
• the format of Audio Stream Packets is illustrated in FIG. 13.
• this type of packet is structured to have Packet Length, Packet Type, bClient ID, Audio Channel ID, Reserved 1, Audio Sample Count, Bits Per Sample and Packing, Audio Sample Rate, Parameter CRC, Digital Audio Data, and Audio Data CRC fields.
• this type of packet is generally identified as a Type 32 packet.
• the bClient ID field contains 2 bytes of information that are reserved for a Client ID, as used previously.
• the Reserved 1 field contains 2 bytes that is reserved for future use, and is generally configured at this point with all bits set to zero.
• the Bits Per Sample and Packing field contains 1 byte in the form of an 8-bit unsigned integer that specifies the packing format of audio data.
• the format generally employed is for Bits 4 through 0 to define the number of bits per PCM audio sample.
• Bit 5 then specifies whether or not the Digital Audio Data samples are packed.
• the difference between packed and byte-aligned audio samples is illustrated in FIG. 14.
• a value of O' indicates that each PCM audio sample in the Digital Audio Data field is byte-aligned with an MDDI interface byte boundary, and a value of '1' indicates that each successive PCM audio sample is packed up against the previous audio sample.
• This bit is generally effective only when the value defined in bits 4 through 0 (the number of bits per PCM audio sample) is not a multiple of eight.
• Bits 7 through 6 are reserved for future use and are generally set at a value of zero.
• packet types 1 to 15, 18 to 31, and 33 through 55 are reserved for stream packets to be defined for use in future versions or variations of the packet protocols, as desired for various applications encountered. Again, this is part of making the MDD interface more flexible and useful in the face of ever changing technology and system designs as compared to other techniques. 6.
• Eight data stream types are reserved for use in proprietary applications that may be defined by equipment manufacturers for use with a MDDI link. These are known as User-defined Stream Packets. Such packets may be used for any purpose, but the Host and Client should only employ such packets in situations where the result of such use is very well understood or known. The specific definition of the stream parameters and data for these packet types is left to the specific equipment manufacturers implementing such packet types or seeking their use. Some exemplary uses of the User-defined Stream Packets are to convey test parameters and test results, factory calibration data, and proprietary special use data.
• the format of the user-defined stream packets as used in one embodiment is illustrated in FIG. 15. As shown in FIG. 15, this type of packet is structured to have Packet Length (2 bytes), Packet Type, bClient ID number, Stream Parameters, Parameter CRC, Stream Data, and Stream Data CRC fields.
• the color map packets specify the contents of a color map look-up table used to present colors for a client. Some applications may require a color map that is larger than the amount of data that can be transmitted in a single packet. In these cases, multiple Color Map packets may be transferred, each with a different subset of the color map by using the offset and length fields described below.
• the format of the Color Map Packet in one embodiment is illustrated in FIG. 16. As shown in FIG. 16, this type of packet is structured to have Packet Length, Packet Type, hClient ID, Color Map Item Count, Color Map Offset, Parameter CRC, Color Map Data, and Data CRC fields.
• this type of packet is generally identified as a Type 64 packet (Video Data Format and Color Map Packet) as specified in the Packet Type Field (2 bytes).
• a Client indicates an ability to receive Color Map Packets using the Color Map Size and Color Map Width fields of the Display Capability Packet.
• data is transferred in the reverse direction using a Reverse Link Encapsulation Packet.
• a forward link packet is sent and the MDDI link operation (transfer direction) is changed or turned around the middle of this packet so that packets can be sent in the reverse direction.
• the format of the Reverse Link Encapsulation packet in one embodiment is illustrated in FIG. 17. As shown in FIG. 17, this type of packet is structured to have Packet Length, Packet Type, hCLient ID, Reverse Link Flags, Reverse Rate Divisor, Turn-Around 1 Length, Turn-Around 2 Length, Parameter CRC, All Zero 1, Turn- Around 1, Reverse Data Packets, All Zero 2, Turn- Around 2, and Driver re- enable fields.
• This type of packet is generally identified as a Type 65 packet. For External Mode every host must be able to generate this packet and receive data, and every client must be able to receive and send data to the host. Implementation of this packet is optional for Internal Mode.
• the MDDI link controller behaves in a special manner while sending a Reverse Link Encapsulation Packet.
• the MDD interface has a strobe signal that is always driven by the host as controller of the link.
• the host behaves as if it were transmitting a zero for each bit of the Turn-Around and Reverse Data Packets portions of the Reverse Link Encapsulation packet.
• the host toggles a MDDI_Strobe signal at each bit boundary during the two turn-around times and during the time allocated for reverse data packets.
• the host disables its MDDI data signal line drivers during the time period specified by Turn- Around 1, and the client re- enables its line drivers during the Driver Re-enable field following the time period specified by Turn-Around 2 field.
• the client reads the Turn-Around Length parameter and drives the data signals toward the host immediately after the last bit in the Turn-Around 1 field. That is, the client clocks new data into the link on certain rising edges of the MDDI strobe as specified in the packet contents description below, and elsewhere.
• the client uses the Packet Length and Turn-Around Length parameters to know the length of time it has available to send packets to the host.
• the client may send filler packets or drive the data lines to a zero state when it has no data to send to the host. If the data lines are driven to zero, the host interprets this as a packet with a zero length (not a valid length) and the host does not accept any more packets from the client for the duration of the current Reverse Link Encapsulation Packet.
• the Host drives the MDD Data signals to the logic-zero level during the All Zero 1 field
• a client drives the MDDI data lines to a logic-zero level for at least one reverse link clock period before the start of the Turn Around 2 field, that is during the All Zero 2 field period. This keeps the data lines in a deterministic state during the Turn Around 1 and Turn Around 2 fields time period. If the client has no more packets to send, it may even disable the data lines after driving them to a logic-zero level because the hibernation bias resistors (discussed elsewhere) keep the data lines at a logic-zero level for the remainder of the Reverse Data Packets field, or a duration of about 16 forward link bytes or more.
• the Reverse Link Request field of the Display Request and Status Packet may be used to inform the host of the number of bytes the client needs in the Reverse Link Encapsulation Packet to send data back to the host.
• the host attempts to grant the request by allocating at least that number of bytes in the Reverse Link Encapsulation Packet.
• the host may send more than one Reverse Link Encapsulation Packet in a sub-frame.
• the display may send a Display Request and Status Packet at almost any time, and the host will interpret the Reverse Link Request parameter as the total number of bytes requested in one sub-frame.
• a host needs to know the capability of the client (display) it is communicating with in order to configure the host-to-client link in an generally optimum or desired manner. It is recommended that a display send a Display Capability Packet to the host after forward link synchronization is acquired. The transmission of such a packet is considered required when requested by the host using the Reverse Link Flags in the Reverse Link Encapsulation Packet.
• the Display Capability Packet is used to inform the host of the capabilities of a display. For External Mode every host must be able to receive this packet, and every display must be able to send this packet to fully utilize this interface and protocol. Implementation of this packet is optional for Internal Mode, since the capabilities of the display should already be well defined and known to the host at the time of manufacture or assembly into a single component or unit of some type.
• FIG. 18 The format of the Display Capability packet in one embodiment is illustrated in FIG. 18. As shown in FIG. 18, this type of packet is structured to have Packet Length, Packet Type, Protocol Version, Min Protocol Version, Bitmap Width, Bitmap Height, Monochrome Capability, Color Map Capability, RGB Capability, Y Cr Cb Capability, Display Feature Capability, Data Rate Capability, Frame Rate Capability, Audio Buffer Depth, Audio Stream Capability, Audio Rate Capability, Min Sub-frame rate, and CRC fields. In an exemplary embodiment, this type of packet is generally identified as a Type 66 packet. 10. Keyboard Data Packets
• a keyboard data packet is used to send keyboard data from the client device to the host.
• a wireless (or wired) keyboard may be used in conjunction with various displays or audio devices, including, but not limited to, a head mounted video display/audio presentation device.
• the Keyboard Data Packet relays keyboard data received from one of several known keyboard-like devices to the host. This packet can also be used on the forward link to send data to the keyboard.
• a client indicates an ability to send and receive Keyboard Data Packets using the Keyboard Data Field in the. Display Capability Packet.
• FIG. 19 The format of a Keyboard Data Packet is shown in FIG. 19, and contains a variable number of bytes of information from or for a keyboard. As shown in FIG. 19, this type of packet is structured to have Packet Length, Packet Type, bClient DD, Keyboard Data Format, Keyboard Data, and CRC fields. Here, this type of packet is generally identified as a Type 67 packet.
• the bClient ID is a reserved field, as before, and the CRC is performed over all bytes of the packet.
• the Keyboard Data Format field contains a 2 bytes value that describes the keyboard data format. Bits 6 through 0 should be identical to the Keyboard Data Format field in the Display Capability Packet. This value is not to equal 127. Bits 15 through 7 are reserved for future use and are, therefore, currently set to zero.
• a pointing device data packet is used to send position information from a wireless mouse or other pointing device from the display to the host. Data can also be sent to the pointing device on the forward link using this packet.
• An exemplary format of a Pointing Device Data Packet is shown in FIG. 20, and contains a variable number of bytes of information from or for a pointing device. As shown in FIG. 20, this type of packet is structured to have Packet Length, Packet Type, Pointing Device Data, and CRC fields. In an exemplary embodiment, this type of packet is generally identified as a Type 68 packet in the 1-byte type field.
• a Link Shutdown Packet is sent from the host to the client display to indicate that the MDDI data and strobe will be shut down and go into a low-power consumption "hibernation" state.
• This packet is useful to shut down the link and conserve power after static bitmaps are sent from a mobile communication device to the display, or when there is no further information to transfer from a host to a client for the time being. Normal operation is resumed when the host sends packets again.
• the first packet sent after hibernation is a sub-frame header packet.
• the format of a Display Status Packet is shown in FIG. 21. As shown in FIG. 21, this type of packet is structured to have Packet Length, Packet Type, and CRC fields.
• this type of packet is generally identified as a Type 69 packet in the 1-byte type field, and uses a pre-selected fixed length of 3 bytes.
• the MDDI_Data driver is disabled into a high- impedance state, and the MDDI_Data signals are pulled to a logic zero state using a high- impedance bias network that can be overdriven by the display.
• the strobe signal used by the interface is set to a logic-zero level in the hibernation state to minimize power consumption. Either the host or client may cause the MDDI link to "wake up" from the hibernation state as described elsewhere, which is a key advance for and advantage of the present invention.
• the host needs a small amount of information from the display so it can configure the host-to-display link in a generally optimum manner. It is recommended that the display send one Display Status Packet to the host each sub-frame. The display should send this packet as the first packet in the Reverse Link Encapsulation Packet to ensure that it is delivered reliably to the host.
• the format of a Display Status Packet is shown in FIG. 22. As shown in FIG. 22, this type of packet is structured to have Packet Length, Packet Type, Reverse Link Request, CRC Error Count, and CRC fields. This type of packet is generally identified as a Type 70 packet in the 1-byte type field, and uses a pre-selected fixed length of 8 bytes.
• the Reverse Link Request field may be used to inform the host of the number of bytes the display needs in the Reverse Link Encapsulation Packet to send data back to the host.
• the host should attempt to grant the request by allocating at least that number of bytes in the Reverse Link Encapsulation Packet.
• the host may send more than one Reverse Link Encapsulation Packet in a sub-frame in order to accommodate data.
• the client may send a Display Request and Status Packet at any time and the host will interpret the Reverse Link Request parameter as the total number of bytes requested in one sub-frame. Additional details and specific examples of how reverse link data is sent back to the host are shown below.
• the Bit Block Transfer Packet provides a means to scroll regions of the display in any direction. Displays that have this capability will report the capability in bit 0 of the Display Feature Capability Indicators field of the Display Capability Packet.
• the format of a Bit Block Transfer Packet is shown in FIG. 23. As shown in FIG. 23, this type of packet is structured to have Packet Length, Packet Type, Upper Left X Value, Upper Left Y Value, Window Width, Window Height, Window X Movement, Window Y Movement, and CRC fields. This type of packet is generally identified as a Type 71 packet, and uses a preselected fixed length of 15 bytes.
• the fields are used to specify the X and Y values of the coordinate of the upper left corner of the window to be moved, the width and height of the window to be moved, and the number of pixels that the window is to be moved horizontally, and vertically, respectively. Positive values for the latter two fields cause the window to be moved to the right, and down, and negative values cause movement to the left and up, respectively.
• the Bitmap Area Fill Packet provides a means to easily initialize a region of the display to a single color. Displays that have this capability will report the capability in bit 1 of the Display Feature Capability Indicators field of the Display Capability Packet.
• the format of a Bitmap Area Fill Packet is shown in FIG. 24. As shown in FIG. 24, this type of packet is structured to have Packet Length, Packet Type, Upper Left X Value, Upper Left Y Value, Window Width, Window Height, Data Format Descriptor, Pixel Area Fill Value, and CRC fields. This type of packet is generally identified as a Type 72 packet in the 1- byte type field, and uses a pre-selected fixed length of 17 bytes.
• the Bitmap Pattern Fill Packet provides a means to easily initialize a region of the display to a pre-selected pattern. Displays that have this capability will report the capability in bit 2 of the Display Feature Capability Indicators field of the Display Capability Packet.
• the upper left corner of the fill pattern is aligned with the upper left corner of the window to be filled. If the window to be filled is wider or taller than the fill pattern, then the pattern may repeated horizontally or vertically a number of times to fill the window. The right or bottom of the last repeated pattern is truncated as necessary. If the window is smaller than the fill pattern, then the right side or bottom of the fill pattern may be truncated to fit the window.
• FIG. 25 The format of a Bitmap Pattern Fill Packet is shown in FIG. 25. As shown in FIG. 25, this type of packet is structured to have Packet Length, Packet Type, Upper Left X Value, Upper Left Y Value, Window Width, Window Height, Pattern Width, Pattern Height, Data Format Descriptor, Parameter CRC, Pattern Pixel Data, and Pixel Data CRC fields. This type of packet is generally identified as a Type 73 packet in the 1-byte type field.
• the Communication Link Data Channel Packet provides a means for a display with high-level computing capability, such as a PDA, to communicate with a wireless transceiver such as a cell phone or wireless data port device.
• a wireless transceiver such as a cell phone or wireless data port device.
• the MDDI link is acting as a convenient high-speed interface between the communication device and the computing device with the mobile display, where this packet transports data at a Data Link Layer of an operating system for the device.
• this packet could be used if a web browser, email client, or an entire PDA were built into a mobile display. Displays that have this capability will report the capability in bit 3 of the Display Feature Capability Indicators field of the Display Capability Packet.
• FIG. 26 The format of a Communication Link Data Channel Packet is shown in FIG. 26. As shown in FIG. 26, this type of packet is structured to have Packet Length, Packet Type, Parameter CRC, Communication Link Data, and Communication Data CRC fields. This type of packet is generally identified as a Type 74 packet in the type field.
• the Interface Type Handoff Request Packet enables the host to request that the client or display shift from an existing or current mode to the Type-I (serial), Type-U (2-bit parallel), Type-IU (4-bit parallel), or Type-IV (8-bit parallel) modes. Before the host requests a particular mode it should confirm that the display is capable of operating in the desired mode by examining bits 6 and 7 of the Display Feature Capability Indicators field of the Display Capability Packet.
• the format of a Interface Type Handoff Request Packet is shown in FIG. 27. As shown in FIG. 27, this type of packet is structured to have Packet Length, Packet Type, Interface Type, and CRC fields. This type of packet is generally identified as a Type 75 packet, and uses a pre-selected fixed length of 4 bytes.
• the Interface Type Acknowledge Packet is sent by the display to confirm receipt of the Interface Type Handoff Packet.
• the requested mode Type-I (serial), Type-U (2-bit parallel), Type-UI (4-bit parallel), or Type-IV (8-bit parallel) mode, is echoed back to the host as a parameter in this packet.
• the format of a Interface Type Acknowledge Packet is shown in FIG. 28. As shown in FIG. 28, this type of packet is structured to have Packet Length, Packet Type, Interface Type, and CRC fields. This type of packet is generally identified as a Type 76 packet, and uses a pre-selected fixed length of 4 bytes.
• the Perform Type Handoff Packet is a means for the host to command the display to handoff to the mode specified in this packet. This is to be the same mode that was previously requested and acknowledged by the Interface Type Handoff Request Packet and Interface Type Acknowledge Packet. The host and display should switch to the agreed upon mode after this packet is sent. The display may lose and re-gain link synchronization during the mode change.
• the format of a Perform Type Handoff Packet is shown in FIG. 29. As shown in FIG. 29, this type of packet is structured to have Packet Length, Packet Type, Packet Type, and CRC fields. This type of packet is generally identified as a Type 77 packet in the 1-byte type field, and uses a pre-selected fixed length of 4 bytes.
• This packet allows the host to enable or disable audio channels in the display. This capability is useful so the display (client) can power off audio amplifiers or similar circuit elements to save power when there is no audio to be output by the host. This is significantly more difficult to implement implicitly simply using the presence or absence of audio streams as an indicator.
• the default state when the display system is powered-up is that all audio channels are enabled.
• the format of a Forward Audio Channel Enable Packet is shown in FIG. 30. As shown in FIG 30, this type of packet is structured to have Packet Length, Packet Type, Audio Channel Enable Mask, and CRC fields. This type of packet is generally identified as a Type 78 packet in the 1-byte type field, and uses a pre-selected fixed length of 4 bytes.
• This packet allows the host to enable or disable the reverse-link audio channel, and to set the audio data sample rate of this stream.
• the host selects a sample rate that is defined to be valid in the Display Capability Packet. If the host selects an invalid sample rate then the display will not send an audio stream to the host.
• the host may disable the reverse-link audio stream by setting the sample rate to 255.
• the default state assumed when the display system is initially powered-up or connected is with the reverse-link audio stream disabled.
• the format of a Reverse Audio Sample Rate Packet is shown in FIG. 31. As shown in FIG. 31, this type of packet is structured to have Packet Length, Packet Type, Audio Sample Rate, and CRC fields. This type of packet is generally identified as a Type 79 packet, and uses a pre-selected fixed length of 4 bytes.
• This packet allows the host and a display to exchange messages related to the digital content protection method being used.
• Presently two types of content protection are contemplated, Digital Transmission Content Protection (DTCP), or High-bandwidth Digital Content Protection System (HDCP), with room reserved for future alternative protection scheme designations.
• the method being used is specified by a Content Protection Type parameter in this packet.
• the format of a Digital Content Protection Overhead Packet is shown in FIG. 32. As shown in FIG. 32, this type of packet is structured to have Packet Length, Packet Type, Content Protection Type, Content Protection Overhead Messages, and CRC fields. This type of packet is generally identified as a Type 80 packet.
• the Transparent Color Enable Packet is used to specify which color is transparent in a display and to enable or disable the use of a transparent color for displaying images. Displays that have this capability will report that capability in bit 4 of the Display Feature Capability Indicators field of the Display Capability Packet. When a pixel with the value for transparent color is written to the bitmap, the color does not change from the previous value.
• the format of a Transparent Color Enable Packet is shown in FIG. 33. As shown in FIG. 33, this type of packet is structured to have Packet Length, Packet Type, Transparent Color Enable, Data Format Descriptor, Transparent Pixel Value, and CRC fields. This type of packet is generally identified as a Type 81 packet in the 1-byte type field, and uses a preselected fixed length of 10 bytes.
• the Round Trip Delay Measurement Packet is used to measure the propagation delay from the host to a client (display) plus the Delay from the client (display) back to the host. This measurement inherently includes the delays that exist in the line drivers and receivers, and an interconnect sub-system. This measurement is used to set the turn around delay and reverse link rate divisor parameters in the Reverse Link Encapsulation Packet, described generally above. This packet is most useful when the MDDI link is running at the maximum speed intended for a particular application.
• the MDDI_Stb signal behaves as though all zero data is being sent during the following fields: All Zero, both Guard Times, and the Measurement Period. This causes MDDI_Stb to toggle at half the data rate so it can be used as periodic clock in the display during the Measurement Period.
• FIG. 34 The format of a of Round Trip Delay Measurement Packet is shown in FIG. 34. As shown in FIG. 34, this type of packet is stractured to have Packet Length, Packet Type, Parameter CRC, All Zero, Guard Time 1, Measurement Period, Guard Time 2, and Driver Re-enable fields. This type of packet is generally identified as a Type 82 packet, and uses a pre-selected fixed length of 533 bits.
• FIG. 35 The timing of events that take place during the Round Trip Delay Measurement Packet are illustrated in FIG. 35.
• the host transmits the Round Trip Delay Measurement Packet, shown by the presence of the Parameter CRC and Strobe Alignment fields followed by the All Zero and Guard Time 1 fields.
• a delay 3502 occurs before the packet reaches the client display device or processing circuitry.
• the display receives the packet, it transmits the Oxff, Oxff, 0x0 pattern as precisely as practical at the beginning of the Measurement Period as determined by the display.
• the actual time the display begins to transmit this sequence is delayed from the beginning of the Measurement Period from the point of view of the host.
• the amount of this delay is substantially the time it takes for the packet to propagate through the line drivers and receivers and the interconnect subsystem.
• a similar amount of delay 3504 is incurred for the pattern to propagate from the display back to the host.
• the host In order to accurately determine the round trip delay time for signals traversing to and from the client, the host counts the number of bit time periods occurring after the start of the Measurement Period until the beginning of the Oxff, Oxff, 0x0 sequence is detected upon arrival. This information is used to determine the amount of time for a round trip signal to pass from the host to the client and back again. Then, about one half of this amount is attributed to a delay created for the one way passage of a signal to the client.
• the display disables its line drivers substantially immediately after sending the last bit of the Oxff, Oxff, 0x0 pattern.
• Guard Time 2 allows time for the display's line drivers to go completely to the high-impedance state before the host transmits the Packet Length of the next packet.
• the hibernation pull-up and pull-down resistors (see FIG. 42) ensure that the MDDI_Data signals are held at a valid low level in the intervals where the line drivers are disabled in both the host and display.
• the Forward Link Skew Calibration Packet allows a client or Display to calibrate itself for differences in the propagation delay of the MDDI_Data signals with respect to the MDDI_Stb signal. Without delay skew compensation, the maximum data rate is generally limited to account for potential worst-case variation in these delays. Generally, this packet is only sent when the forward link data rate is configured to a rate of around 50 Mbps or lower. After sending this packet to calibrate the display, the data rate may be stepped up above 50 Mbps.
• the display might synchronize to an alias of the bit period which could cause the delay skew compensation setting to be off by more than one bit time, resulting in erroneous data clocking.
• the highest data rate type of interface or greatest possible Interface Type is selected prior to sending the Forward Link Skew Calibration Packet so that all existing data bits are calibrated.
• FIG. 56 The format of a Forward Link Skew Calibration Packet is shown in FIG. 56. As shown in FIG. 56, this type of packet is structured to have Packet Length (2 bytes), Packet Type, Parameter CRC, Calibration Data Sequence, and CRC fields. This type of packet is generally identified as a Type 83 packet in the type field, and has a pre-selected length of 515. Virtual Control Panel
• VCP Virtual Control Panel
• the use of a Virtual Control Panel allows a host to set certain user controls in a client. By allowing these parameters to be adjusted by the host, the user interface in the client can be simplified because screens that allow a user to adjust parameters such as audio volume or display brightness can be generated by host software rather than by one or more microprocessors in the client.
• the host has the ability to read the parameter settings in the client and to determine the range of valid values for each control.
• the client has the capability to report back to the host which control parameters can be adjusted.
• VCP Codes The control codes (VCP Codes) and associated data values generally specified, are utilized to specify controls and settings in the client.
• the VCP Codes in the MDDI specification are expanded to 16 bits to preserve proper data field alignment in the packet definitions, and in the future to support supplementary values that are unique to this interface or future enhancements.
• the Request VCP Feature Packet provides a means, mechanism, or method for the host to request the current setting of a specific control parameter or all valid control parameters.
• a client responds to a VCP Packet with the appropriate information in a VCP Feature Reply Packet.
• the client indicates an ability to support the Request VCP Feature Packet using bit 20 of the Display Feature Capability Indicators field of the Display Capability Packet.
• FIG. 69 The format of the Request VCP Feature Packet in one embodiment is shown in FIG. 69. As seen in FIG. 69, this type of packet is stractured to have Packet Length, Packet Type, hClient ID, MCCS VCP code, and CRC fields. This type of packet is generally identified in one embodiment as a Type 128, which is indicated in the 2 byte type field. The packet length, which specifies the total number of bytes in the packet not including the packet length field, is typically fixed for this type of packet at a length of 8 bytes.
• the hClient ID field contains a 16-bit unsigned integer reserved for the Client ID. This field is reserved for future use and is typically set to zero.
• the MCCS VCP Code field comprises 2 bytes of information that specifies the MCCS VCP Control Code Parameter. A value in the range of 0 to 255 causes a VCP Feature Reply Packet to be returned with a single item in the VCP Feature Reply List corresponding to the specified MCCS code.
• An MCCS VCP Code of 65535 (Oxffff) requests a VCP Feature Reply Packet with a VCP Feature Reply List containing a Feature Reply List Item for each control supported by the client.
• the values of 256 through 65534, for this field are reserved for future use and presently not in use.
• the VCP Feature Reply Packet provides a means, mechanism, or method for a client to respond to a host request with the current setting of a specific control parameter or all valid control parameters.
• the client sends the VCP Feature Reply Packet in response to the Request VCP Feature Packet. This packet is useful to determine the current setting of a specific parameter, to determine the valid range for a specific control, to determine if a specific control is supported by the client, or to determine the set of controls that are supported by the client.
• a VCP Feature Reply Packet is returned with a single VCP Feature Reply List item corresponding to the unimplemented control that contains the appropriate error code.
• the client indicates an ability to support the VCP Feature Reply Packet using bit 20 of the Display Feature Capability Indicators field of the Display Capability Packet.
• VCP Feature Reply Packet The format of the VCP Feature Reply Packet in one embodiment is shown in FIG. 70. As seen in FIG. 70, this type of packet is stractured to have Packet Length, Packet Type, cClient ID, MCCS Version, Reply Seqeunce Number, VCP Feature Reply List, and CRC fields. This type of packet is generally identified in one embodiment as a Type 129, as indicated in the 2 byte type field.
• the cClient ID field contains information reserved for a Client J_D. This field is reserved for future use and is generally set to zero.
• MCCS Version field contains 2 bytes of information that specifies the Version of the VESA MCCS Specification implemented by the client.
• the 2 byte Reply Sequence Number field contains information or data that specifies the sequence number of the VCP Feature Reply Packets returned by the client.
• the client returns one or more VCP Feature Reply Packets in response to a Request VCP Feature Packet with an MCCS Control Code value of 65535.
• the client may spread the feature reply list over multiple VCP Feature Reply Packets. In this case, the client assigns a sequence number to each successive packet, and the sequence numbers of the VCP Feature Reply Packets sent in response to a single Request VCP Feature Packet starts at zero and increments by one.
• the last VCP Feature List Item in the last VCP Feature Reply Packet should contain an MCCS VCP Control Code value equal to Oxffff to identify that the packet is the last one and contains the highest sequence number of the group of packets returned. If only one VCP Feature Reply Packet is sent in response to a Request VCP Feature Packet then the Reply Sequence Number in that single packet is zero and the VCP Feature Reply List contains a record having an MCCS VCP Control Code equal to Oxfffff.
• the Number of Features in List field contains 2 bytes that specifies the number of VCP Feature List Items that are in the VCP Feature Reply List in this packet, while the VCP Feature Reply List field is a a group of bytes that contain one or more VCP Feature Reply List Items.
• the format of a single VCP Feature Reply List Item in one embodiment is shown in FIG. 71.
• each VCP Feature Reply List Item is exactly 12 bytes in length, and comprises the MCCS VCP Code, Result Code, Maximum Value, and Present Value fields.
• the 2-byte MCCS VCP Code field contains data or infomraitn that specifies the MCCS VCP Control Code Parameter associated with this list item. Only the Control Code values defined in the VESA MCCS Specification version 2 and later are considered as valid.
• the 2-byte Result Code field contains information that specifies an error code related to the request for information regarding the specified MCCS VCP Control. A value of '0' in this field means there is no error, while a value of '1' means the specified control is not implemented in the client. Further values for this field of 2 through 65535 are currently reserved for future use and implementation of other application contemplated by the art, but are not to be used for now.
• the 4-byte Maximum Value field contains a 32-bit unsigned integer that specifies the largest possible value to which the specified MCCS Control can be set. If the requested control is not implemented in the client this value is set to zero. If the value returned is less than 32 bits (4 bytes) in length, then the value is cast into a 32-bit integer leaving the most significant (unused) bytes set to zero.
• the 4-byte Present Value field contains information that specifies the present value of the specified MCCS VCP Continuous (C) or non- continuous (NC) control. If the requested control is not implemented in the client or if the control is implemented but is a table (T) data type, then this value is set to zero. If the value returned is less than 32 bits (4 bytes) in length per the VESA MCCS specification then the value is cast into a 32-bit integer leaving the most significant (unused) bytes set to zero. 29. Set VCP Feature Packet
• the Set VCP Feature Packet provides a means, mechanism, or method for a host to set VCP control values for both continuous and non-continuous controls in a client.
• the client indicates the ability to support the Set VCP Feature Packet using bit 20 of the Display Feature Capability Indicators field of the Display Capability Packet.
• FIG. 72 The format of the Set VCP Feature Packet in one embodiment is shown in FIG. 72.
• this type of packet is structured to have Packet Length, Packet Type, hClient ID, MCCS VCP Code, Number of Vlaues in List, Control Value List, and CRC fields.
• This type of packet is generally identified as a Type 130, as indicated in the 2 byte type field, is 20 bytes long exclusive of the Packet Length field.
• the hClient TD field again uses a 2-byte value to specify or act as a Client TD. This field is reserved for future use and is currently set to zero.
• the MCCS VCP Code field uses 2 bytes of information or values to specify the MCCS VCP Control Code Parameter to be adjusted.
• the 2-byte Number of Values in List Field contains information or values that specifies the number of 16-bit values that exist in the Control Value List.
• the Control Value List will usually contain one item unless the MCCS Control Code relates to a table in the client. In the case of non-table-related controls, The Control Value List will contain a value that specifies the new value to be written to the control parameter specified by the MCCS VCP Code field.
• Control Value List For table-related controls the format of the data in the Control Value List is specified by the parameter description of the specified MCCS VCP Code. If the list contains values that are larger than one byte, then the least-significant byte is transmitted first, consistent with the method defined elsewhere. Finally, the 2-byte CRC field contains a 16-bit CRC of all bytes in the packet including the Packet Length.
• the Request Valid Parameter Packet is used as a means or mechanism to request that a client return a Valid Parameter Reply Packet containing a list of parameters supported by the specified non-continuous (NC) or table (T) control.
• This packet should only specify non-continuous controls or controls that relate to a table in the client, and not specify a MCCS VCP Code value of 65535 (Oxffff) to specify all controls. If a non-supported or invalid MCCS VCP Code is specified then an appropriate error value is returned in the Valid Parameter Reply Packet.
• the client indicates an ability to support the Request Valid Parameter Packet using bit 20 of the Display Feature Capability Indicators field of the Display Capability Packet.
• FIG. 73 The format of the Request Valid Parameter Packet in one embodiment is shown in FIG. 73. As seen in FIG. 73, this type of packet is stractured to have Packet Length, Packet Type, hClient ID, MCCS VCP Code, and CRC fields. This type of packet is generally identified in one embodiment as a Type 131, as indicated in the 2 byte type field.
• the packet length as indicated in the 2-bytes Packet Length Field is generally set to have a total number of bytes in the packet, not including the packet length field of 8.
• the hClient JJD again specifies the Client TD, but is currently reserved for future use, as would be apparent to one skilled in the art, and is set to zero.
• the 2-byte MCCS VCP Code Filed contains a value that specifies the non-continuous MCCS VCP Control Code Parameter to be queried. The value in this field should correspond to a non-continuous control that is implemented in the client.
• the values 256 through 65535 (Oxffff) are typically reserved or considered as invalid, and are considered as an unimplemented control in the error response.
• a Valid Parameter Reply Packet is sent in response to a Request Valid Parameter Packet. It is used as a means, method, or mechanism to identify the valid settings for a non- continuous MCCS VCP control or a control that returns the contents of a table. If the control relates to a table in the client, then the VCP Parameter Reply List simply contains the specific list of sequential table values that were requested. If the contents of the table cannot fit into a single Valid Parameter Reply Packet then multiple packets with sequential Reply Sequence Numbers can be sent by the client.
• a client indicates an ability to support a Valid Parameter Reply Packet using bit 20 of the Display Feature Capability Indicators field of the Display Capability Packet.
• a host may request the contents of a table in the following manner: the host sends a Set VCP Feature Packet containing the necessary or desired parameters such as read/write parameter, LUT offset, and RGB selection; then a Request Valid Parameter Packet that specifies the desired control is sent by the host; then the client returns one or more Valid Parameter Reply Packets containing the table data.
• This sequence of operations performs a similar function as the table reading functions described in the MCCS operation model.
• the corresponding field of this packet will contain a value of 255.
• the corresponding field should contain a value of the parameter in the client.
• FIG. 74 The format of the Valid Parameter Reply Packet for one embodiment is shown in FIG. 74. As seen in FIG. 74, this type of packet is stractured to have Packet Length, Packet Type, cClient TD, MCCS VCP Code, Response Code, Reply Sequence Number, Number Values in List, VCP Parameter Reply List, and CRC fields. This type of packet is generally identified for one embodiment as a Type 132, as indicated in the 2 byte type field.
• the cClient TD field is reserved for the future Client TD, as is known from the above discussions, while the 3-byte MCCS VCP Code Packet contains a value that specifies a non-continuous MCCS VCP Control Code Parameter that is described by this packet. If an invalid MCCS VCP Control Code is specified by a Request Valid Parameter Packet, then the same invalid parameter value will be specified in this field with the appropriate value in the Response Code field. If the MCCS Control Code is invalid then the VCP Parameter Reply List will have zero length.
• the Response Code field contains 2 bytes of information or values that specify the nature of the response related to the request for information regarding the specified MCCS VCP Control. If the value in this field is equal to 0, then no error is considered as being present for this data type, and the last Valid Parameter Reply Packet in the sequence is sent, it having the highest Reply Sequence Number. If the value in this field is equal to 1, then no error is considered as being present, but other Valid Parameter Reply Packets will be sent that have higher sequence numbers. If the value in this field is equal to 2, then the specified control is not considered as being implemented in the client.
• the specified control is not a non-continuous control (it is a continuous control that always has a valid set of all values from zero to its maximum value). Values for this field equal to 4 through 65535 are reserved for future use and generally not to be used.
• the 2-byte Reply Sequence Number field specifies the sequence number of the Valid Parameter Reply Packets returned by the client.
• the client returns one or more Valid Parameter Reply Packets in response to a Request Valid Parameter Packet.
• the client may spread the VCP Parameter Reply List over multiple Valid Parameter Reply Packets. In this latter case, the client will assign a sequence number to each successive packet, and set the Response Code to 1 in all but the last packet in the sequence.
• the last Valid Parameter Reply Packet in the sequence will have the highest Reply Sequence Number and the Response Code contains a value of 0.
• the 2-byte Number of Values in List field specifies the number of 16-bit values that exist in the VCP Parameter Reply List.
• the VCP Parameter Reply List field contains a list of 0 to 32760 2-byte values that indicate the set of valid values for the non-continuous control specified by the MCCS Control Code field.
• the definitions of the non-continuous control codes are specified in the VESA MCCS Specification.
• the CRC field contains a 16-bit CRC of all bytes in the packet including the Packet Length.
• the MDD interface and associate inventive protocol and mechanisms for communicating data over a communications link provides support for multiple image planes that overlap each other and can have varying degrees of transparency.
• a hardware cursor can be implemented using an overlapping image that has a variable X-Y offset.
• the Alpha-Cursor Image Capability Packet is used to define the characteristics of the alpha-cursor image and associated transparency maps in a client.
• a client indicates an ability to support an Alpha-Cursor Image Capability Packet using a parameter value of 133 in the Valid Parameter Reply List of the Valid Status Reply List Packet.
• the packet length specified in the packet length field is set to a fixed value of 20 for one embodiment, not including the packet length field.
• FIG. 75 The format of the Alpha-Cursor Image Capability Packet for one embodiment is shown in FIG. 75. As seen in FIG. 75, this type of packet is stractured to have Packet Length, Packet Type, cClient ID, Alpha-Cursor Identifier, Alpha-Cursor Bitmap Width, Alpha-Cursor Bitmap Height, RGB Capability, Monochrome Capability, Reserved 1, Y Cr Cb Capability, Transparency Map Res., Capability Bits, and CRC fields.
• the cClient ID field is typically reserved for future Client ID use and currently set to zero.
• the Alpha Cursor Identifier field (2 bytes) contains a value that identifies a specific alpha-cursor plane. If the client supports n alpha-cursor image planes then the Alpha- Cursor Identifier has a valid range of 0 to n - 1. In one embodiment, the value n is specified by the Alpha-Cursor Image Planes field of the Display Capability Packet. The client returns a unique Alpha-Cursor Image Capability Packet for each alpha-cursor image plane.
• the 2-byte Alpha-Cursor Bitmap Width field value specifies the width of the alpha- cursor bitmap image expressed as a number of pixels
• the 2-byte Alpha-Cursor Bitmap Height field value specifies the height of the alpha-cursor bitmap image expressed as a number of pixels.
• the RGB Capability field - 2 bytes that contain a 16-bit unsigned integer that specifies the number of bits of resolution that can be displayed in RGB format. If the client cannot use the RGB format then this value is zero.
• the RGB Capability word is composed of three separate values, which in one embodiment are implemented such that: Bits 3 through 0 define the maximum number of bits of blue (the blue intensity) in each pixel; Bits 7 through 4 define the maximum number of bits of green (the green intensity) in each pixel; Bits 11 through 8 define the maximum number of bits of red (the red intensity) in each pixel; with Bits 15 through 12 being reserved for future use in presenting RGB capability information and are set to zero for now.
• the 1-byte Monochrome Capability field is used to specify the number of bits of resolution that can be displayed in monochrome format. If a client cannot use the monochrome format then this value is zero. Bits 7 through 4 are reserved for future use and are, therefore, generally set to zero. Bits 3 through 0 define the maximum number of bits of grayscale that can exist in each pixel. These four bits make it possible to specify that each pixel consists of 1 to 15 bits. If the value is zero then the monochrome format is not supported by the client.
• the 1-byte Reserved 1 field contains a value generally reserved for future use, and as such all bits in this field are set to zero. This will cause subsequent 2-byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address.
• the 2-byte Y Cb Cr Capability field contains values or information that specifies the number of bits of resolution that can be displayed in Y Cb Cr format. If the client cannot use the Y Cr Cb format then this value is zero.
• the Y Cb Cr Capability word is composed of three separate values with: Bits 3 through 0 defining a maximum number of bits that specify the Cr sample; Bits 7 through 4 defining the maximum number of bits that specify the Cb sample; Bits 11 through 8 defining the maximum number of bits that specify the Y sample; and with Bits 15 through 12 being reserved for future use in presenting Y Cb Cr Capability information or values, but currently being set to zero.
• the 1-byte Transparency Map Resolution field contains values or information that specifies the number of bits (depth) in each pixel location of the alpha-cursor image transparency map. This value may range from 1 to 8, If the value is zero then the transparency map is not supported for this alpha-cursor image buffer (the buffer specified by the Alpha-Cursor Identifier Field).
• the 1-byte Capability Bits field provides values or information that contains a set of flags that specify capabilities associated with the alpha-cursor image buffer.
• the flags are defined such that: Bit 0 acts to select Pixel data in the alpha- Cursor Video Stream Packet to be in a packed format. Bit 1 acts to show that transparency map data in the Alpha-Cursor Transparency Packet is in a packet format. An example of byte-aligned and packed transparency map data is shown in FIG. 76. Bit 2 acts to show that the alpha-cursor image plane supports image offset capability using the Alpha-Cursor Image Offset Packet. Bit 3 acts to show that the alpha-cursor image plane can support a color map data format. The same color map table is used for the alpha-cursor image planes as is used for the main image buffer and scaled video streams. The color map is configured using the Color Map Packet described elsewhere.
• Bits 7 through 4 are reserved for future use and are generally, therefore, set to a zero value or logic level..
• the Alpha-Cursor Transparency Map Packet defines the contents of the image transparency map for the specified alpha-cursor image plane. Some applications may require a transparency map that is larger than the amount of data that can be transmitted in a single packet. In these cases, multiple Alpha-Cursor Transparency Map Packets may be sent, each with a different subset of the transparency map by using the Transparency Map X and Y Start fields described below. These fields operate in a similar manner as the X Start and Y Start fields of the Video Stream Packet.
• a client indicates an ability to support the Alpha-Cursor Transparency Map Packet in one embodiment using the Transparency Map Resolution field of the Alpha-Cursor Image Capability Packet for each specific Alpha- Cursor Plane specified by the Alpha-Cursor Identifier field of the Alpha-Cursor Image Capability Packet.
• the packet length and Client TD fields operate as before for other packets discussed above.
• a value of 134 in the Packet Type field is used to identify a packet as a Alpha-Cursor Transparency Map Packet.
• FIG. 76 The format of the Alpha-Cursor Transparency Map Packet for one embodiment is shown in FIG. 76. As seen in FIG. 76, this type of packet is stractured to have Packet Length, Packet Type, hClient ID, Alpha-Cursor Identifier, Transparency Map X Start, Transparency Map Y Start, Transparency Map Resolution, Reserved 1, Parameter CRC, Transparency Map Media, and Transparency Map Data CRC fields.
• the 2-byte Alpha Cursor Identifier field has a value that identifies a specific alpha- cursor plane. If the client supports n alpha-cursor image planes then the Alpha-Cursor Identifier has a valid range of 0 to n - 1.
• the 2-byte Transparency Map X and Y Start fields each specify the absolute X and Y coordinates, where the point (Transparency Map X Start, Transparency Map Y Start) is the first pixel in the Transparency Map Data field below.
• the transparency Map Resolution field (1 byte) contains a value that specifies the resolution of the transparency map and whether or not the data is packed.
• Bits 3 through 0 define the number of bits of resolution that exist in all transparency map table items. Valid values specify the width to be from 1 to 8 bits. Values 0 and 9 through 15 are considered invalid. This value should match the value returned by a client in the Transparency Map Resolution field in the Alpha-Cursor Image Capability Packet. Bits 6 through 4 are reserved for future use and are, therefore, generally shall be set to logic-zero at this time. Bit 7 of this byte specifies whether or not the Transparency Map Data is in packed or byte-aligned form.
• bit 7 is equal to '1' then the Transparency Map Data is in packed form, and if '0' the data is byte-aligned.
• An example of packed and byte-aligned Transparency Map data is shown in Error! Reference source not found.. The value of this bit must match the value of bit 1 of the Capability Bits field of the Alpha-Cursor Image Capability Packet.
• the 1 bute Reserved 1 field is reserved for future use, therefore, all bits in this field are generally set equal to a logic-zero level. One purpose of this field is to cause all subsequent 2 byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address.
• the Parameter CRC field contain a 16-bit CRC of all bytes from the Packet Length to the Reserved 1 field. If this CRC fails to check then the entire packet is to be discarded.
• each transparency map location is 1 to 8 bits in width. If a single transparency map cannot fit into one Alpha and Cursor Transparency Map Packet, then the entire transparency map may be specified by sending multiple packets with different Transparency Map Data and Transparency Map X and Y Start values in each packet.
• the 2-byte Transparency Map Data CRC field contains a 16-bit CRC of only the Transparency Map Data. If this CRC fails to check then the Transparency Map Data can still be used but the CRC error count shall be incremented
• the Alpha-Cursor Image Offset Packet specifies the X and Y offset of the cursor from the upper left corner of the main display image.
• the format of the Alpha-Cursor Image Offset Packet is illustrated in FIG. 77.
• the Alpha-Cursor Image Offset Packet is structured with Packet Length, Packet Type, hClient ID, Alpha-Cursor X Offset, Alpha-Cursor Y Offset, and CRC fields.
• a client indicates the ability to support the Alpha-Cursor Image Offset Packet using bit 2 of the Capability Bits field of the Alpha-Cursor Image Capability Packet for each specific Alpha-Cursor Plane specified by the Alpha-Cursor Identifier field of the Alpha-Cursor Image Capability Packet.
• the packet length is fixed at 10, as shown in the 2-byte Packet Length field.
• a Packet Type of 135 identifies the packet as an Alpha-Cursor Image Offset Packet.
• the 2-byte Alpha-Cursor X and Y Offset fields contain values that specify the horizontal and vertical, respectively, offset of the left-most column and top row, respectively of pixels of the cursor image from the left side and top of the main image.
• the hClient TD - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ID. This field is reserved for future use and shall be set to zero.
• the Alpha-Cursor Video Stream Packet carries video data to update a rectangular region of an alpha-cursor image plane. The size of this region may be as small as a single pixel or as large as the entire display.
• the format of the Alpha-Cursor Video Stream Packet is illustrated in FIG. 78, As shown in FIG 78, in one embodiment the Alpha-Cursor Video Stream Packet is stractured with Packet Length, Packet Type, bClient JD, Video Data Format Attributes, X Left Edge, Y Top Edge, X Rigth Edge, Y Bottom Edge, X Start, Y Start, Pixel Count, Parameter Crc Pixel Data, and Pixel Data CRC fields.
• a client indicates an ability to support the Alpha-Cursor Video Stream Packet and its associated parameters by using the Alpha-Cursor Image Capability Packet for each specific Alpha-Cursor Plane specified by the Alpha-Cursor Identifier field of the Alpha- Cursor Image Capability Packet, and a value of 17 in the packet type field indicates or identifies a packet as being an Alpha-Cursor Video Stream Packet.
• the hClient ID field (2 bytes) is reserved for future use as a Client ID, and is generally set to zero in the meantime, as would be well understood in the art.
• the 2-byte Video Data Format Descriptor field contains information or a value that specifies the format of each pixel in the Pixel Data in the present stream in the present packet.
• the pixel data format must comply with at least one of the valid formats for the alpha-cursor image plane as defined in the Alpha-Cursor Image Capability Packet.
• the Video Data Format Descriptor field contains a value that defines the pixel format for the current packet only and does not imply that a constant format will continue to be used for the lifetime of a particular video stream. Error! Reference source not found, illustrates how the Video Data Format Descriptor is coded.
• the format is as follows:
• the video data when bits [15:13] are '000' then the video data consists of an array of monochrome pixels where the number of bits per pixel is defined by bits 3 through 0 of the Video Data Format Descriptor word. Bits 11 through 4 are then set to zero. When bits [15:13] are '001' then the video data consists of an array of color pixels that each specify a color through a color map (palette). Bits 5 through 0 of the Video Data Format Descriptor word define the number of bits per pixel, and Bits 11 through 6 are set to zero.
• the video data consists of an array of color pixels in raw RGB format where the number of bits per pixel of red is defined by bits 11 through 8, the number of bits per pixel of green is defined by bits 7 through 4, and the number of bits per pixel of blue is defined by bits 3 through 0.
• the total number of bits in each pixel is the sum of the number of bits used for red, green, and blue.
• the video data consists of an array of video data in 4:2:2 Y Cb Cr format with luminance and chrominance information.
• the number of bits per pixel of luminance (Y) is defined by bits 11 through 8
• the number of bits of the Cb component is defined by bits 7 through 4
• the number of bits of the Cr component is defined by bits 3 through 0.
• the Cb and Cr components are sent at half the rate as Y.
• the video samples in the Pixel Data portion of this packet will be organized as follows: Cbn, Yn, Crn, Yn+1, Cbn+2, Yn+2, Crn+2, Yn+3, ...
• Yn, Yn+1, Yn+2 and Yn+3 are luminance values of four consecutive pixels in a single row from left to right.
• the ordering of the color components is the same as the Microsoft UYVY FOURCC format. If there are an odd number of pixels in a row (X Right Edge - X Left Edge + 1) in the window referenced by the Video Stream Packet then the Cb value corresponding to the last pixel in each row will be followed by the Y value of the first pixel of the next row.
• the Pixel Data in a packet shall contain an even number of pixels. It may contain an odd or even number of pixels in the case where the last pixel of the Pixel Data corresponds to the last pixel of a row in the window specified in the Video Stream Packet header, i.e. when the X location of the last pixel in the Pixel Data is equal to X Right Edge.
• bit 12 (designated as "P" in the figures) specifies whether or not the Pixel Data samples are packed. When the value of bit 12 is '0' then each pixel and each color within each pixel in the Pixel Data field is byte-aligned with an MDDI interface byte boundary. When the value of bit 12 is '1' then each pixel and each color within each pixel in the Pixel Data is packed up against the previous pixel or color within a pixel leaving no unused bits.
• the Pixel Data Attributes field (2 byte) has a series of bit values that are interpreted as follows. Bits 1 and 0 select how the display pixel data is routed. For bit values of '11' data is displayed to or for both eyes, for bit values '10', data is routed only to the left eye, and for bit values '01', data is routed only to the right eye.
• Bit 2 indicates whether or not the Pixel Data is presented in an interlace format, with a value of '0' meaning the pixel data is in the standard progressive format, and that the row number (pixel Y coordinate) is incremented by 1 when advancing from one row to the next.
• this bit has a value of 1', the pixel data is in interlace format, and the row number is incremented by 2 when advancing from one row to the next.
• Bit 3 indicates that the Pixel Data is in alternate pixel format. This is similar to the standard interlace mode enabled by bit 2, but the interlacing is vertical instead of horizontal.
• Bit 3 is '0' the Pixel Data is in the standard progressive format, and the column number (pixel X coordinate) is incremented by 1 as each successive pixel is received.
• Bit 3 is '1' the Pixel Data is in alternate pixel format, and the column number is incremented by 2 as each pixel is received.
• Bit 4 indicates whether or not the Pixel data is related to a display or a camera, as where data is being transferred to or from an internal display for a wireless phone or similar device or even a portable computer, or such other devices as discussed above, or the data is being transferred to or from a camera built into or directly coupled to the device.
• Bit 4 is '0' the Pixel data is being transferred to or from a display frame buffer.
• Bit 4 is '1' Pixel data is being transferred to or from a camera or video device of some type, such devices being well known in the art.
• Bit 5 is reserved for future use or applications of the MDD interface and is, therefore, generally set as zero value or '0'.
• Bits 7 and 6 are Display Update Bits that specify a frame buffer where the pixel data is to be written. The more specific effects are discussed elsewhere. For bit values of '01' Pixel data is written to the offline image buffer. For bit values of '00' Pixel data is written to the image buffer used to refresh the display. For bit values of '11' Pixel data is written to all image buffers. The bit values or combination of '10' is treated as an invalid value or designation and Pixel data is ignored and not written to any of the image buffers. This value may have use for future applications of the interface.
• Bits 8 through 15 are reserved for future use and are, therefore, generally set as zero.
• the 2-byte X Start and Y Start fields specify the absolute X and Y coordinates of the point (X Start, Y Start) for the first pixel in the Pixel Data field.
• the 2-byte X Left Edge and Y Top Edge fields specify the X coordinate of the left edge and Y coordinate of the top edge of the alpha-cursor image window filled by the Pixel Data field, while the X Right Edge and Y Bottom Edge fields specify the X coordinate of the right edge, and the Y coordinate of the bottom edge of the alpha-cursor image window being updated.
• the Pixel Count field (2 bytes) specifies the number of pixels in the Pixel Data field below.
• the 2-byte Parameter CRC field contains a CRC of all bytes from the Packet Length to the Pixel Count. If this CRC fails to check then the entire packet is discarded.
• the Pixel Data field contains the raw video information that is to be displayed, and which is formatted in the manner described by the Video Data Format Descriptor field. The data is transmitted one "row" at a time as discussed elsewhere.
• the Pixel Data CRC field (2 bytes) contains a 16-bit CRC of only the Pixel Data. If a CRC verification of this value fails then the Pixel Data can still be used, but the CRC error count is incremented.
• the MDD Interface or protocol mechanism or method provides support for scaled video stream images that allow the host to send an image to the client that is scaled larger or smaller than the original image, and the scaled image is copied to a main image buffer.
• An overview of the Scaled Video Stream functionality and associated protocol support is provided elsewhere, An ability to support scaled video streams is defined by or within the Scaled Video Stream Capability Packet, which is sent in response to a Request Specific Status Packet.
• the Scaled Video Stream Capability Packet defines the characteristics of the scaled video stream source image in or used by a client.
• the format of the Scaled Video Stream Capability Packet is shown generally in FIG. 79.
• a Scaled Video Stream Capability Packet is structured to have Packet Length, Packet Type, cClient TD, Max Number of Streams, Source Max X Size, Source Max Y size, RGB Capability, Monochrome Capability, Reserved 1, Y Cr Cb Capability, Reserved 2, and CRC fields.
• Thr packet length in one embodiment, is selected to be a fixed 20 bytes, as shown in the length field, including the 2-byte cClient TD field, reserved for use for a Client ID, otherwise set to zero, and the .CRC field.
• the client indicates an ability to support the Scaled Video Stream Capability Packet using a parameter value of 143 in the Valid Parameter Reply List of the Valid Status Reply List Packet.
• the 2-byte Maximum Number of Streams field contains a value to identify the maximum number of simultaneous scaled video streams that may be allocated at one time.
• a client should deny a request to allocate a scaled video stream if the maximum number of scaled video streams are already allocated. If less than the maximum number of scaled video streams are allocated the client may also deny an allocation request based on other resource limitations in the client.
• the Source Maximum X Size and Y size fields (2 bytes) specify values for the maximum width and height, respectively, of the scaled video stream source image expressed as a number of pixels.
• the RGB Capability field uses values to specify the number of bits of resolution that can be displayed in RGB format. If the scaled video stream cannot use the RGB format then this value is set equal to zero.
• the RGB Capability word is composed of three separate unsigned values with: Bits 3 through 0 defining a maximum number of bits of blue (the blue intensity) in each pixel, Bits 7 through 4 defining the maximum number of bits of green (the green intensity) in each pixel, and Bits 11 through 8 defining the maximum number of bits of red (the red intensity) in each pixel, while Bits 15 through 12 are reserved for future use in future capability definitions, and are generally set to zero.
• the 1-byte Monochrome Capability field contains a value that specifies the number of bits of resolution that can be displayed in monochrome format. If the scaled video stream cannot use the monochrome format then this value is zero. Bits 7 through 4 are reserved for future use and should, therefore, be set to zero ('0') for current applications, although this may change over time, as will be appreciated by those skilled in the art. Bits 3 through 0 define the maximum number of bits of grayscale that can exist in each pixel. These four bits make it possible to specify that each pixel consists of 1 to 15 bits. If the value is zero, then the monochrome format is not supported by the scaled video stream.
• the Reserved 1 field (here 1 byte) is reserved for future use in providing values related to the Scaled Video Stream Packet information or data. Therefore, currently, all bits in this field are set to a logic '0'.
• One purpose of this field is to cause all subsequent 2-byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address.
• the 2-byte Y Cb Cr Capability field contain values that specify the number of bits of resolution that can be displayed in Y Cb Cr format. If the scaled video stream cannot use the Y Cb Cr format then this value is zero.
• the Y Cb Cr Capability word is composed of three separate unsigned values with: Bits 3 through 0 defining the maximum number of bits that specify the Cr sample; Bits 7 through 4 defining the maximum number of bits that specify the Cb sample; Bits 11 through 8 defining the maximum number of bits specify the Y sample; and with Bits 15 through 12 being reserved for future use and is generally set to zero.
• the 1-byte Capability Bits field contains an 8-bit unsigned integer that contains a set of flags that specify capabilities associated with the scaled video stream.
• the flags are defined as follows: Bit 0 covers Pixel data in the Scaled Video Stream Packet can be in a packed format. An example of packed and byte-aligned pixel data is shown in Error! Reference source not found.Bit 1 is reserved for future use and shall be set to zero; Bit 2 is reserved for future use and shall be set to zero; Bit 3 covers scaled video streams that can be specified in the color map data format.
• the same color map table is used for the scaled video streams as is used for the main image buffer and the alpha-cursor image planes. The color map is configured using the Color Map Packet described in elsewhere; and Bits 7 through 4 are reserved for future use and are generally set to be zero.
• the Reserved 2 field (here 1 byte) is reserved for future use in providing values related to the Scaled Video Stream Packet information or data. Therefore, currently, all bits in this field are set to a logic '0'. One purpose of this field is to cause all subsequent 2-byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address. 37. Scaled Video Stream Setup Packet
• the Scaled Video Stream Setup Packet is used to define the parameters of the scaled video stream and the client uses the information to allocate internal storage for buffering and scaling of the image.
• a stream may be de-allocated by sending this packet with the X Image Size and Y Image Size fields equal to zero. Scaled video streams that have been deallocated may be reallocated later with the same or different stream parameters.
• a client indicates an ability to support the Scaled Video Stream Setup Packet using a parameter value of 143 in the Valid Parameter Reply List of the Valid Status Reply List Packet, and by using a non-zero value in the Maximum Number of Streams field of the Scaled Video Stream Capability Packet.
• Packet definition is illustrated in Error! Reference source not found.. Scaled Video Stream Setup Packet 2 byt ⁇ s 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes
• Packet Length - 2 bytes that contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field.
• the packet length of this packet is always 24.
• a Packet Type of 136 identifies the packet as a Scaled Video Stream Setup Packet.
• hClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ID. This field is reserved for future use and shall be set to zero
• Stream ID - 2 bytes that contain a 16-bit unsigned integer that specifies a unique identifier for the Stream ID. This value is assigned by the host and shall be from zero to the maximum Stream ID value specified in the Display Capability Packet. The host must manage the use of Stream ID values carefully to ensure that each active stream is assigned a unique value, and that streams that are no longer active are deallocated or reassigned.
• the pixel data format must comply with at least one of the valid formats for the alpha-cursor image plane as defined in the Alpha-Cursor Image Capability Packet.
• the Video Data Format Descriptor defines the pixel format for the current packet only and does not imply that a constant format will continue to be used for the lifetime of a particular video stream. Error! Reference source not found, illustrates how the Video Data Format Descriptor is coded.
• the format is as follows:
• the video data consists of an array of color pixels in raw RGB format where the number of bits per pixel of red is defined by bits 11 through 8, the number of bits per
• pixel of green is defined by bits 7 through 4
• the number of bits per pixel of blue is defined by bits 3 through 0.
• the total number of bits in each pixel is the sum of the number of bits used for red, green, and blue.
• the video data consists of an array of video data in 4:2:2 Y Cb Cr format with luminance and chrominance information.
• the number of bits per pixel of luminance (Y) is defined by bits 11 through 8
• the number of bits of the Cb component is defined by bits 7 through 4
• the number of bits of the Cr component is defined by bits 3 through 0.
• the Cb and Cr components are sent at half the rate as Y.
• the video samples in the Pixel Data portion of this packet will be organized as follows: Cbn, Yn, Crn, Yn+1, Cbn+2, Yn+2, Crn+2, Yn+3, ...
• Yn, Yn+1, Yn+2 and Yn+3 are luminance values of four consecutive pixels in a single row from left to right.
• the ordering of the color components is the same as the Microsoft UYVY FOURCC format. If there are an odd number of pixels in a row (X Right Edge - X Left Edge + 1) in the window referenced by the Video Stream Packet then the Cb value corresponding to the last pixel in each row will be followed by the Y value of the first pixel of the next row.
• the Pixel Data in a packet shall contain an even number of pixels. It may contain an odd or even number of pixels in the case where the last pixel of the Pixel Data corresponds to the last pixel of a row in the window specified in the Video Stream Packet header, i.e. when the X location of the last pixel in the Pixel Data is equal to X Right Edge.
• Bits [1 :0] 10 - data is routed to the left eye only.
• Bits [1:0] 01 - data is routed to the right eye only.
• Bit 2 indicates that the Pixel Data is in interlace format.
• Bit 2 is 0 - Pixel Data is in the standard progressive format. The row number (pixel Y coordinate) shall be incremented by 1 when advancing from one row to the next.
• Bit 2 is 1 - Pixel Data is in interlace format. The row number (pixel Y coordinate) shall be incremented by 2 when advancing from one row to the next.
• Bit 3 indicates that the Pixel Data is in alternate pixel format. This is similar to the standard interlace mode enabled by bit 2, but the interlacing is vertical instead of horizontal.
• Bit 3 is 0 - Pixel Data is in the standard progressive format. The column number (pixel X coordinate) shall be incremented by 1 as each successive pixel is received.
• Bit 3 is 1 - Pixel Data is in alternate pixel format. The column number (pixel X coordinate) shall be incremented by 2 as each pixel is received.
• Bit 4 indicates whether the Pixel data is related to the display or the camera.
• Bit 4 is 0 - Pixel Data is to or from the display frame buffer.
• Bit 4 is 1 - Pixel Data is to or from the camera.
• Bit 5 is reserved for future use and shall be set to zero.
• Bits [7:6] 00 - Pixel data is written to the image buffer used to refresh the display.
• Bits [7:6] 11 - Pixel data is written to all image buffers.
• Bits [7:6] 10 - Invalid. Reserved for future use. Pixel data is ignored and not written to any of the image buffers. [00379] Bits 8 through 15 are reserved for future use and shall be set to zero. [00380] X Left Edge - 2 bytes that contain a 16-bit unsigned integer that specifies the X coordinate of the left edge of the destination image. [00381] Y Top Edge - 2 bytes that contain a 16-bit unsigned integer that specifies the Y coordinate of the top edge of the destination image. [00382] X Right Edge - 2 bytes that contain a 16-bit unsigned integer that specifies the X coordinate of the right edge of the destination image.
• Y Bottom Edge - 2 bytes that contain a 16-bit unsigned integer that specifies the Y coordinate of the bottom edge of the destination image.
• X Image Size - 2 bytes that contain a 16-bit unsigned integer that specifies the width of the source image.
• Y Image Size - 2 bytes that contain a 16-bit unsigned integer that specifies the height of the source image.
• CRC - 2 bytes that contain a 16-bit CRC of all bytes in the packet including the Packet Length.
• the Scaled Video Stream Acknowledgement Packet allows a client to acknowledge the receipt of a Scaled Video Stream Setup Packet.
• the client shall indicate its ability to support the Scaled Video Stream Acknowledgement Packet via a parameter value of 143 in the Valid Parameter Reply List of the Valid Status Reply List Packet and via a non-zero value in the Maximum Number of Streams field of the Scaled Video Stream Capability Packet.
• Packet definition is illustrated in. Scaled Video Stream Acknowledgement Packet 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes
• Packet Contents [00389] Packet Length - 2 bytes that contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field. The packet length of this packet is always 10. [00390] Packet Type -A Packet Type of 137 identifies the packet as a Scaled Video Stream Acknowledgement Packet. [00391] cClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client TD. This field is reserved for future use and shall be set to zero. [00392] Stream ID - 2 bytes that contain a 16-bit unsigned integer that specifies a unique identifier for the Stream ID.
• the 2- byte Ack Code field provides values containing a code that describes the outcome of an attempt to update the specified scaled video stream.
• the codes are defined as follows: [00394] 0 - The stream allocation attempt was successful.
• the Scaled Video Stream Packet is used to transmit the pixel data associated with a specific scaled video stream.
• the size of the region reference by this packet is defined by the Scaled Video Stream Setup Packet.
• the client shall indicate its ability to support the Scaled Video Stream Packet via a parameter value of 143 in the Valid Parameter Reply List of the Valid Status Reply List Packet and via a successful scaled video stream allocation response in the Ack Code field of the Scaled Video Stream Acknowledgement Packet.
• FIG. -1 Scaled Video Stream Packet 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes 2 bytes Packet Length - 12 bytes 2 bytes Figure -1, Scaled Video Stream Packet Packet Contents: [00405] Packet Length - 2 bytes that contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field. [00406] Packet Type - 2 bytes that contain a 16-bit unsigned integer. A Packet Type of 18 identifies the packet as a Scaled Video Stream Packet.
• hClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client TD. This field is reserved for future use and shall be set to zero
• Stream ID - 2 bytes that contain a 16-bit unsigned integer that specifies a unique identifier for the Stream ID. This value is specified by the host in the Scaled Video Stream Setup Packet and confirmed in the Scaled Video Stream Acknowledgement Packet.
• Parameter CRC - 2 bytes that contain a 16-bit CRC of all bytes from the Packet Length to the Pixel Count. If this CRC fails to check then the entire packet shall be discarded.
• Pixel Data The raw video information to be scaled and then displayed. Data is formatted in the manner described by the Video Data Format Descriptor field. The data is transmitted a row at a time as defined in section Error! Reference source not found..
• the Request Specific Status Packet provides a means for the host to request that the client send a capability or status packet back to host as specified in this packet.
• the client shall return the packet of the specified type in the next Reverse Link Encapsulation Packet.
• the client will set bit 17 in the Display Feature Capability Indicators field of the Display Capability Packet if the client has the capability to respond to the Request Specific Status Packet.
• the client shall indicate its ability to support the Request Specific Status Packet via bit 21 of Display Feature Capability Indicators field of the Display Capability Packet.
• Request Specific Status Packet Packet Contents [00414] Packet Length - 2 bytes that contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field. The Packet Length of this packet is always 10. [00415] Packet Type - 2 bytes that contain a 16-bit unsigned integer. A Packet Type of 138 identifies the packet as a Request Specific Status Packet. [00416] hClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ID. This field is reserved for future use and shall be set to zero.
• [00426] 56 through 63 - can be used for manufacturer-specific capability and status identifiers. [00427] CRC - 2 bytes that contain a 16-bit CRC of all bytes in the packet including the Packet Length.
• the Valid Status Reply List Packet provides the host with a list of status and capability packets to which the client has the capability to respond.
• the client shall indicate its ability to support the Valid Status Reply List Packet via bit 21 of Display Feature Capability Indicators field of the Display Capability Packet.
• Packet Length - 2 bytes that contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field.
• the Packet Length of this packet is always 10.
• a Packet Type of 139 identifies the packet as a Valid Status Reply Packet.
• cClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client TD. This field is reserved for future use and shall be set to zero.
• the Packet Types that may be included in this list and their meaning are:
• 133 - Alpha-Cursor Image Capability Packet can be sent by the client.
• Packet Processing Delay Parameters Packet can be sent by the client.
• 143 - Scaled Video Stream Capability Packet can be sent by the client.
• 144 - Display Identification Packet can be sent by the client.
• 56 through 63 - can be used for manufacturer-specific capability and status identifiers.
• the Packet Processing Delay Parameters Packet provides a set of parameters to allow the host to compute the time required to complete the processing associated with the reception of a specific packet type. Some commands sent by the host cannot be completed by the client in zero time. The host may poll the status bits in the Display Request and Status Packet to determine if certain functions have been completed by the client, or the host may compute the completion time using the parameters returned by the client in the Packet Processing Delay Parameters Packet. The client shall indicate its ability to support the Packet Processing Delay Parameters Packet via a parameter value of 140 in the Valid Parameter Reply List of the Valid Status Reply List Packet.
• Packet Contents [00446] Packet Length - 2 bytes that contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field. The Packet Length of this packet is always 10. [00447] Packet Type - 2 bytes that contain a 16-bit unsigned integer. A Packet Type of 140 identifies the packet as a Packet Processing Delay Parameters Packet. [00448] cClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ID. This field is reserved for future use and shall be set to zero.
• Each Delay Parameters List Item is exactly 6 bytes in length, and is defined as follows:
• Packet Type for Delay - 2 bytes that contain a 16-bit unsigned integer that specifies the Packet Type for which the following delay parameters apply.
• Pixel Delay - 1 byte that contains an 8-bit unsigned integer that is an index to a delay value.
• the value read from the table is multiplied by the total number of pixels in the destination field of the packet.
• the total number of pixels is the width times the height of the destination area of the bitmap referenced by the packet. Equation 0-1 is used to compute the total delay.
• Horizontal Pixel Delay - 1 byte that contains an 8-bit unsigned integer that is an index to a delay value table (same table as DPVL). The value read from the table is multiplied by the width (in pixels) of the destination field of the packet. Equation 0-1 is used to compute the total delay.
• the TotalPixels, Width, or Height do not apply because those parameters are not referenced in the corresponding packet. In those cases the corresponding Pixel Delay parameter shall be zero.
• the Personal Display Capability Packet provides a set of parameters that describe the capabilities of a personal display device, such as a head-mounted display or display glasses. This enables the host to customize the display information according to the specific capabilities of a client.
• a client indicates an ability to send the Personal Display Capability Packet by using a corresponding parameter in the Valid Parameter Reply List of the Valid Status Reply List Packet.
• Packet Length - 2 bytes that contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field.
• the Packet Length of this packet is always 68.
• a Packet Type of 141 identifies the packet as a Personal Display Capability Packet.
• cClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ID. This field is reserved for future use and shall be set to zero.
• the Sub-Pixel Layout field contains an 8-bit unsigned integer that specifies the physical layout of a sub-pixel from top to bottom and left to right, using value of: 0 to indicate that a sub-pixel layout is not defined; 1 to indicate red, green, blue stripe; 2 to indicate blue, green, red stripe; 3 to indicate a quad-pixel, having a 2-by-2 sub-pixel arrangement of red at the top left, blue at the bottom right, and two green sub-pixels, one at the bottom left and the other at the top right; 4 to indicate a quad-pixel, with a 2-by-2 sub- pixel arrangement of red at the bottom left, blue at the top right, and two green sub-pixels, one at the top left and the other at the bottom right; 5 to indicate a Delta (Triad); 6 to indicate a mosaic with red, green, and blue overlayed (e.g. LCOS display with field- sequential color); and with values 7 through 255 being generally reserved for future use.
• 0 indicates that a sub-pixel layout
• the Pixel Shape field contains an 8-bit unsigned integer that specifies the shape of each pixel that is composed of a specific configuration sub-pixels, using a value of: 0 to indicate that a sub-pixel shape is not defined; 1 to indicate round; 2 to indicate square; 3 to indicate rectangular; 4 to indicate oval; 5 to indicate elliptical; and with the values 6 through 255 being reserved for future use in indicating desired chapes, as can be appreciated by one skilled in the art.
• HFOV field - 1 byte that contains an 8-bit unsigned integer that specifies the horizontal field of view in 0.5 degree increments (e.g. if the HFOV is 30 degrees, this value is 60). If this value is zero then the HFOV is not specified.
• VFOV field - 1 byte that contains an 8-bit unsigned integer that specifies the vertical field of view in 0.5 degree increments (e.g. if the VFOV is 30 degrees, this value is 60). If this value is zero then the VFOV is not specified.
• Visual Axis Crossing field - 1 byte that contains an 8-bit unsigned integer that specifies the visual axis crossing in 0.01 diopter (1/m) increments (e.g. if the visual axis crossing is 2.22 meters, this value is 45). If this value is zero then the Visual Axis Crossing is not specified. ⁇ Note: is the specification of this parameter appropriate for the desired range in most applications? ⁇
• Left Right Image Overlap field - 1 byte that contains an 8-bit unsigned integer that specifies the percentage of overlap of the left and right image.
• the allowable range of the image overlap in percent is 1 to 100. Values of 101 to 255 are invalid and shall not be used. If this value is zero then the image overlap is not specified.
• See Through field - 1 byte that contains an 8-bit unsigned integer that specifies the see-through percentage of image.
• the allowable range of see-through in percent is 0 to 100. Values of 101 to 254 are invalid and shall not be used. If this value is 255 then the see-through percentage is not specified.
• Maximum Brightness field - 1 byte that contains an 8-bit unsigned integer that specifies the maximum brightness in increments of 20 nits (e.g. if the maximum brightness is 100 nits, this value is 5). If this value is zero then the maximum brightness is not specified.
• the display is binocular and can display 2-dimensional (2D) images only.
• the display is binocular and can display 3-dimensional (3D) images.
• Inter-Pupillary Distance Minimum - 1 byte that contains an 8-bit unsigned integer that specifies the minimum inter-pupillary distance in millimeters (mm). If this value is zero then the minimum inter-pupillary distance is not specified.
• Inter-Pupillary Distance Maximum - 1 byte that contains an 8-bit unsigned integer that specifies the maximum inter-pupillary distance in millimeters (mm). If this value is zero then the maximum inter-pupillary distance is not specified.
• Points of Field Curvature List a list of 25 2-byte parameters that specify the focal distance in thousandths of a diopter (1/m) with a range of 1 to 65535 (e.g. 1 is 0.001 diopters and 65535 is 65.535 diopters).
• the 25 elements in the Points of Field Curvature List are labeled Al through E5 as shown in Error! Reference source not found, below.
• the points shall be evenly distributed over the active area of the display.
• Column C corresponds to the vertical axis of the display and row 3 corresponds to the horizontal axis of the display.
• Columns A and E correspond to the left and right edges of the display, respectively.
• rows 1 and 5 correspond to the top and bottom edges of the display, respectively.
• the Display Error Report Packet acts as a mechanism or means for allowing a client to provide a list of operating errors to the host.
• the client may detect a wide range of errors in the course of its normal operation as a result of receiving certain commands from the host. Examples of these errors include: the client may have been commanded to operate in a mode that it does not support, the client may have received a packet containing certain parameters that are out of range or are beyond the capability of the client, the client may have been commanded to enter a mode in an improper sequence.
• the Display Error Report Packet may be used to detect errors during normal operation, but is most useful to the system designer and integrator to diagnose problems in development and integration of host and client systems.
• the client shall indicate its ability to send the Display Error Report Packet via a parameter value of 142 in the Valid Parameter Reply List of the Valid Status Reply List Packet.
• a Packet Type of 142 identifies the packet as a Display Error Report Packet.
• cClient ID - 2 bytes that contain is reserved for the Client ID. This field is reserved for future use and shall be set to zero.
• each Error Report List Item is exactly 4 bytes in length, and has a structure in one embodiment comprising: a 2-byte Display Error Code field that specifies the type of error being reported, a 2-byte Error Sub-code field specifies a greater level of detail regarding the error defined by the Display Error Code packet.
• the specific definition of each Display Error Code is defined by the manufacturer of the client. An Error Sub-code does not have to be defined for every Display Error Code, and in those cases where the Error Sub-code is not defined the value is set to zero.
• the specific definition of each Error Sub-code is defined by the manufacturer of the client.
• the Display Identification Packet allows a client to return identifying data in response to a Request Specific Status Packet.
• a client indicates an ability to send the Display Identification Packet using a parameter value of 144 in the Valid Parameter Reply List of the Valid Status Reply List Packet. It is useful for the host to be able to determine the client device manufacturer name and model number by reading this data from the client. The information may be used to determine if the client has special capabilities that cannot described in the Display Capability Packet. There are potentially two methods, means, or mechanisms for reading identification information from the client. One is through use of the Display Capability Packet, which contains fields similar to those in the base EDID structure.
• the other method is through use of the Display Identification Packet that contains a richer set of information compared to the similar fields in the Display Capability Packet. This allows a host to identify manufacturers that have not been assigned a 3-character EISA code, and allows serial numbers to contain alphanumeric characters.
• the 2- byte Packet Type field contains a value that identifies the packet as a Display Identification Packet. This value is selected to be 144 in one embodiment.
• the cClient ID field (2 bytes) again is reserved for future use for the Client ID, and is generally set to zero.
• the CRC field (2 bytes) contains a 16-bit CRC of all bytes in the packet including the Packet Length.
• a 1-byte Week of Manufacture field contains a value that defines the week of manufacture of the display. In at least one embodiment, this value is in the range of 1 to 53 if it is supported by the client. If this field is not supported by the client, then it is generally set to zero.
• a 1-byte Year of Manufacture field contains a value that defines the year of manufacture of the display. This value is an offset from the year 1990 as a starting point, although other base years could be used. Years in the range of 1991 to 2245 can be expressed by this field. Example: the year 2003 corresponds to a Year of Manufacture value of 13. If this field is not supported by the client it is to be set to a value of zero.
• the Length of Mfr Name, Length of Product Name, and Length of Serial Number fields each contain 2-byte values that specify the length of the Manufacturer Name String field including any null termination or null pad characters, the length of the Product Name String field including any null termination or null pad characters, and the length of the Serial Number String field including any null termination or null pad characters, respectively.
• the Manufacturer Name String, Product Name String, and Serial Number String fields each contain a variable number of bytes specified by the Length Mfr Name, Product Name, and Serial Number fields, respectively, that contain an ASCII string that specifies the manufacturer, product name , and alphanumeric serial number of the display, respectively. Each of these strings are terminated by at least one null character.
• the Alternate Display Capability Packet indicates the capability of the alternate displays attached to the MDDI client controller. It is sent in response to a Request Specific Status Packet. When prompted a client device sends an Alternate Display Capability Packet for each alternate display that is supported. The client shall indicate its ability to send the Alternate Display Capability Packet via a parameter value of 145 in the Valid Parameter Reply List of the Valid Status Reply List Packet.
• the Video stream packet contains 4 bits in the Pixel Data Attributes field to address each alternate display in the client device.
• a Packet Type of 145 identifies the packet as an Alternate Display Capability Packet.
• cClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ID. This field is reserved for future use and shall be set to zero.
• Alt Display Number - 1 byte that contains an 8-bit unsigned integer that indicates the identity of the alternate display with an integer in the range of 0 to 15.
• the first alternate display shall be number 0 and the other alternate displays shall be identified with unique Alt Display Number values with the largest value used being the total number of alternate displays minus 1. Values larger than the total number of alternate displays minus 1 shall not be used.
• Reserved 1 - 1 byte that contains an 8-bit unsigned integer that is reserved for future use. All bits in this field shall be set to zero. The purpose of this field is to cause all subsequent 2 byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address.
• Bitmap Width - 2 bytes that contain a 16-bit unsigned integer that specifies the width of the bitmap expressed as a number of pixels.
• Bitmap Height - 2 bytes that contain a 16-bit unsigned integer that specifies the height of the bitmap expressed as a number of pixels.
• Display Window Width - 2 bytes that contain a 16-bit unsigned integer that specifies the width of the display window expressed as a number of pixels.
• Display Window Height - 2 bytes that contain a 16-bit unsigned integer that specifies the height of the display window expressed as a number of pixels.
• Color Map RGB Width - 2 bytes that contain a 16-bit unsigned integer that specifies the number of bits of the red, green, and blue color components that can be displayed in the color map (palette) display mode. A maximum of 8 bits for each color component (red, green, and blue) can be used. Even though 8 bits of each color component are sent in the Color Map Packet, only the number of least significant bits of each color component defined in this field are used. If the display client cannot use the color map (palette) format then this value is zero.
• the color map RGB Width word is composed of three separate unsigned values:
• Bits 3 through 0 define the maximum number of bits of blue in each pixel. 0 to 8 is valid.
• Bits 7 through 4 define the maximum number of bits of green in each pixel. 0 to 8 is valid.
• Bits 11 through 8 define the maximum number of bits of red in each pixel. 0 to 8 is valid.
• Bits 15 through 12 are reserved for future use and shall be set to zero.
• RGB Capability - 2 bytes that contain a 16-bit unsigned integer that specifies the number of bits of resolution that can be displayed in RGB format. If the client cannot use the RGB format then this value is zero.
• the RGB Capability word is composed of three separate unsigned values:
• Bits 3 through 0 define the maximum number of bits of blue (the blue intensity) in each pixel.
• Bits 7 through 4 define the maximum number of bits of green (the green intensity) in each pixel.
• Bits 11 through 8 define the maximum number of bits of red (the red intensity) in each pixel.
• Bits 15 through 12 are reserved for future use and shall be set to zero.
• Monochrome Capability 1 byte that contains an 8-bit unsigned integer that specifies the number of bits of resolution that can be displayed in monochrome format. If the client cannot use the monochrome format then this value is zero. Bits 7 through 4 are reserved for future use and shall be set to zero. Bits 3 through 0 define the maximum number of bits of grayscale that can exist in each pixel. These four bits make it possible to specify that each pixel consists of 1 to 15 bits. If the value is zero then the monochrome format is not supported by the client.
• Reserved 2 - 1 byte that contains an 8-bit unsigned integer that is reserved for future use. All bits in this field shall be set to zero. The purpose of this field is to cause all subsequent 2 byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address.
• Y Cb Cr Capability - 2 bytes that contain a 16-bit unsigned integer that specifies the number of bits of resolution that can be displayed in Y Cb Cr format. If the client cannot use the Y Cb Cr format then this value is zero.
• the Y Cb Cr Capability word is composed of three separate unsigned values:
• Bits 3 through 0 define the maximum number of bits that specify the Cb sample.
• Bits 7 through 4 define the maximum number of bits that specify the Cr sample.
• Bits 11 through 8 define the maximum number of bits specify the Y sample.
• Bits 15 through 12 are reserved for future use and shall be set to zero.
• Display Feature Capability Indicators - 1 byte that contains an 8-bit unsigned integer that contains a set of flags that indicate the whether specific features in the client are supported. A bit set to one indicates the capability is supported, and a bit set to zero indicates the capability is not supported.
• Bit 0 - the client can accept video data in packed format.
• Bits 1 through 7 - reserved for future use, shall be set to zero.
• the Register Access Packet provides either a host or a client with a means, mechanism, or method to access configuration and status registers in the opposite end of the MDDI link. These registers are likely to be unique for each display or device controller. These registers already exist in many displays that require setting configurations, modes of operation, and have other useful and necessary settings.
• the Register Access Packet allows the MDDI host or client to both write to a register and request to read a register using the MDDI link. When the host or client requests to read a register the opposite end should respond by sending the register data in the same packet type, but also by indicating that this is the data read from a particular register with the use of the Read/Write Info field.
• the Register Access Packet may be used to read or write multiple registers by specifying a register count greater than 1.
• a client indicates an ability to support the Register Access Packet using bit 22 of Display Feature Capability Indicators field of the Display Capability Packet.
• the 2-byte Packet Length field contain a 16-bit unsigned integer that specifies the total number of bytes in the packet not including the packet length field.
• a Packet Type of 146 identifies the packet as a Register Access Packet.
• bClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ED. This field is reserved for future use and shall be set to zero.
• Read/Write Info - 2 bytes that contain a 16-bit unsigned integer that specifies the specific packet as either a write, or a read, or a response to a read, and provides a count of the data values
• bits 13:0 - a 14-bit unsigned integer that specifies the number of 32-bit Register Data items o be transferred in the Register Data List field.
• bits 13:0 specify the number of register data items that are contained in the Register Data List field to be written to client registers starting at the register specified by the Register Address field.
• bit 15 is a 1 in a packet sent by the host bits 13:0 specify the number of register data items that the client shall send to the host.
• the Register Data field in the packet sent by the host shall contain no items and is of zero length.
• bits 13:0 specify the number of register data items that are contained in the Register Data List field.
• Bit 15 shall not be set to 0 in packets sent by the Client. This is not a valid value.
• Register Address 4 bytes that contain a 32-bit unsigned integer that contains the register address that is to be written to or read from. For addressing registers whose addressing is less than 32 bits, the upper bits shall be set to zero.
• Register Data List - a list of 4-byte register data values to be written to client registers or values that were read from client device registers.
• the Frame Sync Packet provides a host an ability to indicate the start of a raster image and allows a client to avoid using the pixel and window addressability features in the Video Stream Packet. This is accomlished by sending a Frame Sync Packet at the start of each frame of the image, and then one Video Stream Packet (with bit 5 set in the Pixel Data Attributes field) is sent for each row of image data.
• a client indicates an ability to support the Frame Sync Packet using bit 23 of the Display Feature Capability Indicators field of the Display Capability Packet.
• Packet Type - 2 bytes that contain a 16-bit unsigned integer.
• a Packet Type of 147 identifies the packet as a Frame Sync Packet.
• bClient ID - 2 bytes that contain a 16-bit unsigned integer reserved for the Client ID.
• the CRC fields appear at the end of the packets and sometimes after certain more critical parameters in a packet that may have a significantly large data field, and thus, an increased likelihood of errors during transfer.
• the CRC generator when only one is used, is re-initialized after the first CRC so that the CRC computations following a long data field are not affected by the parameters at the beginning of the packet.
• the polynomial used for the CRC calculation is known as the CRC-16, or X16 + X15 + X2 + X0.
• a sample implementation of a CRC generator and checker 3600 useful for implementing the invention is shown in FIG. 36.
• a CRC register 3602 is initialized to a value of 0x0001 just prior to transfer of the first bit of a packet which is input on the Tx_MDDI_Data_Before_CRC line, then the bytes of the packet are shifted into the register starting with the LSB first. Note that the register bit numbers in this figure correspond to the order of the polynomial being used, and not the bit positions used by the MDDI.
• the packet contents for the Display Request and Status Packets are: 0x07, 0x46, 0x000400, 0x00 (or represented as a sequence of bytes as: 0x07, 0x00, 0x46, 0x00, 0x04, 0x00, 0x00), and are submitted using the inputs of the multiplexors 3604 and 3606, and NAND gate 3608, the resulting CRC output on the Tx_MDDI_Data_With_CRC line is OxOeal (or represented as a sequence as Oxal, OxOe).
• CRC generator and checker 3600 When CRC generator and checker 3600 is configured as a CRC checker, the CRC that is received on the Rx_MDDI_Data line is input to multiplexor 3604 and NAND gate 3608, and is compared bit by bit with the value found in the CRC register using NOR gate 3610, exclusive-OR (XOR) gate 3612, and AND gate 3614. If there are any errors, as output by AND gate 3614, the CRC is incremented once for every packet that contains a CRC error by connecting the output of gate 3614 to the input of register 3602. Note that the example circuit shown in the diagram of FIG. 36 can output more than one CRC error signal within a given CHECK_CRC_NOW window (see FIG. 37B).
• the CRC error counter generally only counts the first CRC error instance within each interval where CHECK_CRC_NOW is active. If configured as a CRC generator the CRC is clocked out of the CRC register at the time coinciding with the end of the packet.
• FIGS. 37 A and 37B The timing for the input and output signals, and the enabling signals, is illustrated graphically in FIGS. 37 A and 37B.
• the generation of a CRC and transmission of a packet of data are shown in FIG. 37 A with the state (0 or 1) of the Gen_Reset, Check_CRC_Now, Generate_CRC_Now, and Sending_MDDI_Data signals, along with the Tx_MDDI_Data_Before_CRC and Tx_MDDI_Data_With_CRC signals.
• the reception of a packet of data and checking of the CRC value are shown in FIG. 37B, with the state of the GenJReset, Check_CRC_Now, Generate_CRC_Now, and Sending_MDDI_Data signals, along with the Rx_MDDI_Data and CRC error signals.
• a new technique has been developed in which the CRC portion of packets is used to transfer error code information.
• This is generally shown in FIG. 65. That is, one or more error codes are generated by the processors or devices handling the data transfer which indicate specific predefined errors or flaws that might occur within the communication processing or link.
• the appropriate error code is generated and transferred using the bits for the CRC of a packet. That is, the CRC value is overloaded, or overwritten, with the desired error code, which can be detected on the receiving end by an error monitor or checker that monitors the values of the CRC field. For those cases in which the error code matches the CRC value for some reason, the compliment of the error is transferred to prevent confusion.
• the error code may be transferred several times, using a series of packets, generally all, that are transferred or sent after the error has been detected. This occurs until the point at which the condition creating the error is cleared from the system, at which point the regular CRC bits are transferred without overloading by another value.
• a CRC overwriting mechanism or apparatus 6600 is shown using an error detector or detections means 6602, which can form part of other circuitry previously described or known, detects the presence or existence of errors within the communication link or process.
• An error code generator or means 6604 which can be formed as part of other circuitry or use techniques such as look up tables to store preselected error messages, generates one or more error codes to indicate specific predefined errors or flaws that have been detected as occurring. It is readily understood that devices 6602 and 6604 can be formed as a single circuit or device as desired, or as part of a programmed sequence of steps for other known processors and elements.
• a CRC value comparator or comparison means 6606 is shown for checking to see if the selected error code or codes are the same as the CRC value being transferred. If that is the case then a code compliment generator or generation means or device is used to provide the compliment of the error codes as to not be mistaken as the original CRC pattern or value and confuse or complicate the detection scheme. An error code selector or selection means element or device 6610 then selects the error code or value it is desired to insert or overwrite, or their respective compliments as appropriate.
• An error code CRC over-writer or over writing mechanism or means 6612 is a device that receives the data stream, packets, and the desired codes to be inserted and overwrites the corresponding or appropriate CRC values, in order to transfer the desired error codes to a receiving device.
• the error code may be transferred several times, using a series of packets, so the over-writer 6612 may utilize memory storage elements in order to maintain copies of the codes during processing or recall these codes from previous elements or other known storage locations which can be used to store or hold their values as needed, or as desired.
• FIGS. 67 A and 67B The general processing the overwriting mechanism of FIG. 66 is implementing is shown in additional detail in FIGS. 67 A and 67B.
• 67 A an error, one or more, is detected in step 6702 in the communication data or process and an error code is selected in step 6704 to indicate this condition.
• the CRC value to be replaced is checked in a step 6706, and compared to the desired error code in step 6708.
• the result of this comparison is a determination as to whether or not the desired code, or other representative values, will be the same as the CRC value present.
• processing proceeds to a step 6712 where the compliment, or in some cases another representative value, as desired, is selected as the code to insert.
• the compliment or in some cases another representative value, as desired, is selected as the code to insert.
• the packet CRC values are being monitored in a step 6722.
• the CRC values are being monitored by one or more processes within the system to determine if an error in data transfer has occurred and whether or not to request a retransmission of the packet or packets, or to inhibit further operations and so forth, some of which is discussed above.
• the information can also be used to compare values to known or preselected error codes, or representative values and detect the presence of errors. Alternatively, a separate error detection process and monitor can be implemented. If a code appears to be present it is extracted or otherwise noted in step 6724 for further processing.
• step 6726 A determination can be made in step 6726 as to whether or not this is the actual code or a compliment, in which case an additional step 6728 is used to translate the value to the desired code value. In either case the resulting extracted code, compliment, or other recovered values are then used to detect what error has occurred form the transmitted code in step 6730.
• the host When the host restarts the forward link from a hibernation state it drives MDDI_Data to a logic one state for about 150 ⁇ sec and then activates MDDI_Stb and simultaneously drives MDDI_Data to a logic zero state for 50 ⁇ sec, and then starts forward link traffic by sending a sub-frame header packet. This generally allows bus contentions to be resolved before the sub-frame header packet is sent by providing enough settling time between signals.
• the client here a display
• This action causes the host to start or restart data traffic on the forward link (208) and to poll the client for its status.
• the host must detect the presence of the request pulse within 50 ⁇ sec and then begin the startup sequence of driving MDDIJDataO to logic one for 150 ⁇ sec and to logic zero for 50 ⁇ sec.
• the display should not send a service request pulse if it detects MDDI_Data0 in the logic one state for more than 50 ⁇ sec. The nature of selection of the times and tolerances of time intervals related to the hibernation processing and start up sequence are discussed further below.
• FIG. 38 An example of the processing steps for a typical service request event 3800 with no contention is illustrated in FIG. 38, where the events are labeled for convenience in illustration using the letters A, B, C, D, E, F, and G.
• the process commences at point A when the host sends a Link Shutdown Packet to the client device to inform it that the link will transition to a low-power hibernation state.
• the host enters the low- power hibernation state by disabling the MDDI_Data0 driver and setting the MDDI_Stb driver to a logic zero, as shown at point B.
• MDDI_Data0 is driven to a logic-zero level by a high-impedance bias network.
• the client sends a service request pulse to the host by driving MDDIJDataO to a logic one level as seen at point C.
• the host still asserts the logic-zero level using the high-impedance bias network, but the driver in the client forces the line to a logic one level.
• the host recognizes the service request pulse, and asserts a logic one level on MDDIJDataO by enabling its driver, as seen at point D.
• the client then ceases from attempting to assert the service request pulse, and the client places its driver into a high-impedance state, as seen at point E.
• the host drives MDDI_DataO to a logic-zero level for 50 ⁇ sec, as shown at point F, and also begins to generate MDDI_Stb in a manner consistent with the logic-zero level on MDDIJDataO.
• the host After asserting MDDIJDataO to a logic-zero level and driving MDDI_Stb for 50 ⁇ sec, the host begins to transmit data on the forward link by sending a Sub-frame Header Packet, as shown at point G.
• FIG. 39 A similar example is illustrated in FIG. 39 where a service request is asserted after the link restart sequence has begun, and the events are again labeled using the letters A, B, C, D, E, F, and G.
• the process commences at point A when the host again sends a Link Shutdown Packet to the client device to inform it that the link will transition to a low-power hibernation state.
• the host enters the low-power hibernation state by disabling the MDDIJDataO driver and setting the MDDI_Stb driver to a logic zero, as shown at point B.
• MDDIJDataO is driven to a logic-zero level by a high-impedance bias network.
• the host begins the link restart sequence by driving MDDIJDataO to a logic one level for 150 ⁇ sec as seen at point C.
• the display Prior to 50 ⁇ sec passing after the link restart sequence begins the display also asserts MDDIJDataO for a duration of 70 ⁇ sec, as seen at point D. This happens because the display has a need to request service from the host and does not recognize that the host has already begun the link restart sequence.
• the client then ceases attempting to assert the service request pulse, and the client places its driver into a high-impedance state, as seen at point E.
• the host continues to drive MDDIJDataO to a logic one level.
• the host drives MDDIJDataO to a logic zero level for 50 ⁇ sec, as shown at point F, and also begins to generate MDDI_Stb in a manner consistent with the logic zero level on MDDIJDataO.
• the host After asserting MDDIJDataO to a logic-zero level, and driving MDDI_Stb for 50 ⁇ sec, the host begins to transmit data on the forward link by sending a Sub-frame Header Packet, as shown at point G.
• the host drives the MDDIJDataO signal high for 150 ⁇ s, and then drives the MDDIJDataO signal low for 50us while activating the MDDI_Stb line, and then begins to transmit MDDI packets.
• This process works well to advance the state of the art in terms of data rates achievable using the MDDI apparatus and methods.
• more speed in terms of reduced response time to conditions or being able to more quickly select the next step or process are the ability to simplify processing or elements, are always in demand.
• Applicants have discovered a new inventive approach to wake-up processing and timing in which the host uses a clock cycle based timing for the signal toggling.
• the host starts toggling MDDI_Stb from 0 to 10 ⁇ sec after the host drives the MDDIJDataO signal high at the beginning of the wake-up sequence, and does not wait until the signal is driven low.
• the host toggles MDDI_Stb as though the MDDIJDataO signal were always at a logic-zero level. This effectively removes the concept of time from the client side, and the host changes from the prior 150 ⁇ s and 50 ⁇ s periods for the first two states, to 150 clock cycles and 50 clock cycles, for these periods.
• the host now becomes responsible for driving that data line high, and within 10 clock cycles starting to transmit a strobe signal as if the data line was zero. After the host has driven the data line high for 150 clock cycles, the host drives the data line low for 50 clock cycles while continuing to transmit the strobe signal. After it has completed both of these processes, the host can begin to transmit the first sub-frame header packet.
• the client implementation can now use the generated clock to calculate the number of clock cycles that the data line is first high, and then low.
• the number of clock cycles that need to occur in both the data line driven high state is 150 and data line driven low state is 50. This means that for a proper wakeup sequence, the client should be able to count at least 150 continuous clock cycles of the data line being high, followed by at least 50 continuous clock cycles of the data line being low. Once these two conditions are met, the client can begin to search for the unique word of the first sub-frame. A break in this pattern is used as a basis to return the counters to an initial state in which the client again looks for the first 150 continuous clock cycles of the data line being high.
• a client implementation of the invention for host based wakeup from hibernation is very similar to the initial start-up case except that the clock rate is not forced to start at 1Mbps., as discussed earlier. Instead the clock rate can be set to resume at whatever previous rate was active when the communication link went into hibernation. If the host begins transmission of a strobe signal as described above, the client should be able to again count at least 150 continuous clock cycles of the data line being high, followed by at least 50 continuous clock cycles of the data line being low. Once these two conditions have been met, the client can begin the search for the unique word.
• a client implementation of the invention for client based wakeup from hibernation is similar to the host based wakeup except that it starts by having the client driving the data line.
• the client can asynchronously drive the data line without a clock to wake up the host device.
• the host recognizes that the data line is being driven high by the client, it can begin its wakeup sequence.
• the client can count the number of clock cycles generated by the host starting or during its wakeup process. Once the client counts 70 continuous clock cycles of the data being high, it can stop driving the data line high. At this point, the host should already be driving the data line high as well.
• the client can then count another 80 continuous clock cycles of the data line being high to reach the 150 clock cycles of the data line being high, and can then look for 50 clock cycles of the data line being low. Once these three conditions have been met the client can begin to look for the unique word.
• An advantage of this new implementation of wake-up processing is that it removes the need for a time measuring device. Whether this is an oscillator, or capacitor discharge circuit, or other such known devices, the client no longer needs such external devices to determine the start up conditions. This saves money and circuit area when implementing controllers, counters, and so forth on a client device board. While this may not be as advantageous to the client, for the host, this technique should also potentially simplify the host in terms of very high density logic (VHDL) being used for core circuitry.
• VHDL very high density logic
• An advantage of this new implementation of wake-up processing is that it removes the need for a time measuring device. Whether this is an oscillator, or capacitor discharge circuit, or other such known devices, the client no longer needs such external devices to determine the start up conditions. This saves money and circuit area when implementing controllers, counters, and so forth on a client device board. While this may not be as advantageous to the client, for the host, this technique should also potentially simplify the host in terms of very high density logic (VHDL) being used for core circuitry.
• VHDL very high density logic
• FIG. 68A An example of the processing steps for a typical Host-initiated Wake-up with no contention is illustrated in FIG. 68A, where the events are again labeled for convenience in illustration using the letters A, B, C, D, E, F, and G.
• the process commences at point A when the host sends a Link Shutdown Packet to the client device to inform it that the link will transition to a low-power hibernation state.
• point B the host toggles MDDIJStb for about 64 cycles (or as desired for system design) to allow processing by the client to be completed prior to stopping MDDI_Stb from toggling, which stops the recovered clock in the client device.
• the host also initially sets MDDIJDataO to logic-zero level and then disables the MDDIJDataO output in the range of 16 to 48 cycles (generally including output disable propagation delays) after the CRC. It may be desirable to place high-speed receivers for MDDIJDataO and MDDI_Stb in the client in a low power state some time after the 48 cycles after the CRC and prior to the next stage (C).
• the host enters the low-power hibernation state at point or step C, by disabling the MDDIJDataO and MDDI_Stb drivers and placing a host controller in a low power hibernation state.
• the client is also in a low power level hibernation state.
• the host commences the link restart sequence at point D, by enabling the MDDIJDataO and MDDI_Stb driver output.
• the host drives MDDIJDataO to a logic-one level and MDDI_Stb to a logic-zero level for as long as it should take for the drivers to fully enable their respective outputs.
• the host typically waits around 200 nanoseconds after these outputs reach desired logic levels before driving pulses on MMDI_Stb. This allows the client time to prepare to receive.
• the host With the host drivers enabled and MDDIJDataO being driven to a logic-one level, the host begins to toggle MDDI_Stb for a duration of 150 MDDI_Stb cycles, as seen at point E.
• the host drives MDDIJDataO to a logic zero level for 50 cycles, as shown at point F, and the client begins to look for the Sub-frame Header Packet after MDDIJDataO is at a logic-zero level for 40 MDDI_Stb cycles.
• the host begins to transmit data on the forward link by sending a Sub-frame Header Packet, as shown at point G.
• FIG. 68B An example of the processing steps for a typical Client-initiated Wake-up with no contention is illustrated in FIG. 68B, where the events are again labeled for convenience in illustration using the letters A, B, C, D, E, F, G, H, and I.
• the process commences at point A when the host sends a Link Shutdown Packet to inform the client that the link will transition to the low power state.
• the host toggles MDDIJStb for about 64 cycles (or as desired for system design) to allow processing by the client to be completed prior to stopping MDDI_Stb from toggling, which stops the recovered clock in the client device.
• the host also initially sets MDDIJDataO to a logic-zero level and then disables the MDDIJDataO output in the range of 16 to 48 cycles (generally including output disable propagation delays) after the CRC. It may be desirable to place high-speed receivers for MDDIJDataO and MDDIjStb in the client in a low power state some time after the 48 cycles after the CRC and prior to the next stage (C).
• the host enters the low-power hibernation state at point or step C, by disabling the MDDIJDataO and MDDI_Stb drivers and placing a host controller in a low power hibernation state.
• the client is also in a low power level hibernation state.
• the client commences the link restart sequence at point D, by enabling the MDDI_Stb receiver, and also enabling an offset in the MDDI_Stb receiver to guarantee the state of the received version of MDDI Stb is a logic-zero level in the client before the host enables its MDDI Stb driver. It may be desirable for the client to enable the offset slightly ahead of enabling the receiver to ensure the reception of a valid differential signal and inhibit erroneous signals, as desired.
• the Client enables the MDDIJDataO driver while driving the MDDIJDataO line to a logic one level
• the host recognizes the service request pulse from the client, and the host begins the link restart sequence by enabling the MDDIJDataO and MDDLStb driver outputs.
• the host drives MDDIJDataO to a logic-one level and MDDI_Stb to a logic-zero level for as long as it should take for the drivers to enable their respective outputs.
• the host typically waits around 200 nanoseconds after these outputs reach desired logic levels before driving pulses on MDDI_Stb. This allows the client time to prepare to receive.
• the host With the host drivers enabled and MDDIJDataO being driven to a logic-one level, the host begins outputting pulses on MDDI_Stb for a duration of 150 MDDI_Stb cycles, as seen at point F.
• the client recognizes the first pulse on MDDI_Stb it disables the offset in its MDDI_Stb receiver.
• the client continues to drive MDDIJDataO to a logic-one level for 70 MDDI_Stb cycles, and disables its MDDIJDataO driver at point G.
• the host drives MDDIJDataO to a logic-zero level for 50 cycles, and the client begins to look for the Sub-frame Header Packet after MDDIJDataO is at a logic-zero level for 40 MDDI_Stb cycles.
• the host begins to transmit data on the forward link by sending a Sub-frame Header Packet, as shown at point I.
• FIG. 68C An example of the processing steps for a typical Host-initiated Wake-up with contention from the client, that is the client also wants to wake up the link, is illustrated in FIG. 68C.
• the events are again labeled for convenience in illustration using the letters A, B, C, D, E, F, G, H, and I.
• the process commences at point A when the host sends a Link Shutdown Packet to inform the client that the link will transition to the low power state, proceeds to point B where MDDI_Stb is toggled for about 64 cycles (or as desired for system design) to allow processing by the client to be completed, and then to point C, where the host enters the low-power hibernation state, by disabling the MDDIJDataO and MDDI_Stb drivers and placing a host controller in a low power hibernation state.
• the host commences the link restart sequence at point D, by enabling the MDDIJDataO and MDDI_Stb driver output, and begins to toggle MDDI_Stb for a duration of 150 MDDIjStb cycles, as seen at point E.
• the client has not yet recognized that the host is driving MDDIJDataO to a logic-one level so the client also drives MDDIJDataO to a logic-one level. This occurs here because the client has a desire to request service but does not recognize that the host it is trying to communicate with has already begun the link restart sequence.
• the client ceases to drive MDDIJDataO, and places its driver into a high impedance state by disabling its output. The host continues to drive MDDIJDataO to a logic-one level for 80 additional cycles.
• the host drives MDDIJDataO to a logic zero level for 50 cycles, as shown at point H, and the client begins to look for the Sub-frame Header Packet after MDDIJDataO is at a logic-zero level for 40 MDDI_Stb cycles.
• the host begins to transmit data on the forward link by sending a Sub-frame Header Packet, as shown at point I.
• Data in a Non-Return-to-Zero (NRZ) format is encoded using a data-strobe signal or DATA-STB format, which allows clock information to be embedded in the data and strobe signals.
• the clock can be recovered without complex phase lock loop circuitry.
• Data is carried over a bi-directional differential link, generally implemented using a wire-line cable, although other conductors, printed wires, or transfer elements can be used, as stated earlier.
• the strobe signal (STB) is carried over a unidirectional link which is driven only by the host.
• the strobe signal toggles value (0 or 1) whenever there is a back-to-back state, 0 or 1, that remains the same on the Data line or signal.
• FIG. 40 An example of how a data sequence such as bits "1110001011" can be transmitted using DATA-STB encoding is shown in graphical form in FIG. 40.
• a DATA signal 4002 is shown on the top line of a signal timing chart and a STB signal 4004 is shown on a second line, each lime aligned as appropriate (common starting point).
• the STB line 4004 maintains a previous state, thus, the first T state of the DATA signal correlates with the first '0' state for the STB signal, its starting value.
• the STB signal toggles to the opposite state or T in the present example, as is the case in FIG. 40 where the DATA is providing another T value. That is, there is one and only one transition per bit cycle between DATA and STB. Therefore, the STB signal transitions again, this time to '0' as the DATA signal stays at T and holds this level or value as the DATA signal changes level to '0'.
• the STB signal toggles to the opposite state or T in the present example, and so forth, as the DATA signal changes or holds levels or values.
• FIG. 41 An example of circuitry useful for generating the DATA and STB outputs or signals from input data at the host, and then recovering or recapturing the data from the DATA and STB signals at the client, is shown in FIG. 41.
• a transmission portion 4100 is used to generate and transmit the original DATA and STB signals over an intermediary signal path 4102, while a reception portion 4120 is used to receive the signals and recover the data.
• the DATA signal is input to two D-type flip-flop circuit elements 4104 and 4106 along with a clock signal for triggering the circuits.
• the two flip- flop circuit outputs (Q) are then split into a differential pair of signals MDDI_Data0+, MDDIJDataO- and MDDI_Stb+, MDDIjSfb-, respectively, using two differential line drivers 4108 and 4110 (voltage mode).
• a three-input exclusive-NOR (XNOR) gate, circuit, or logic element 4112 is connected to receive the DATA and outputs of both flip-flops, and generates an output that provides the data input for the second flip-flop, which in turn generates the MDDI_Stb+, MDDI_Stb- signals.
• the XNOR gate has the inversion bubble placed to indicate that it is effectively inverting the Q output of the flip- flop that generates the Strobe.
• the MDDI_Data0+, MDDIJDataO- and MDDI_Stb+, MDDI_Stb- signals are received by each of two differential line receivers 4122 and 4124, which generate single outputs from the differential signals.
• the outputs of the amplifiers are then input to each of the inputs of a two-input exclusive-OR (XOR) gate, circuit, or logic element 4126 which produces the clock signal.
• the clock signal is used to trigger each of two D-type flip-flop circuits 4128 and 4130 which receive a delayed version of the DATA signal, through delay element 4132, one of which (4128) generates data '0' values and the other (4130) data T values.
• the clock has an independent output from the XOR logic as well. Since the clock information is distributed between the DATA and STB lines, neither signal transitions between states faster than half of the clock rate. Since the clock is reproduced using the exclusive-OR processing of the DATA and STB signals, the system effectively tolerates twice the amount of skew between the input data and clock compared to the situation when a clock signal is sent directly over a single dedicated data line.
• the MDDI Data pairs, MDDI_Stb+, and MDDI Stb- signals are operated in a differential mode to maximize immunity from the negative affects of noise. Each portion of the differential signal path is source terminated with one-half of the characteristic impedance of the cable or conductor being used to transfer signals. MDDI Data pairs are source terminated at both the host and client ends. Since only one of these two drivers is active at a given time, a termination continuously exists at the source for the transfer link. The MDDI_Stb+ and MDDI_Stb- signals are only driven by the host. [00607] An exemplary configuration of elements useful for achieving the drivers, receivers, and terminations for transferring signals as part of the inventive MDD interface are shown in FIG. 42, while corresponding DC electrical specifications of MDDIJData and MDDI_Stb are shown in Table VII. This exemplary interface uses low voltage sensing, here 200 mV, with less than 1 volt power swings and low power drain.
• the electrical parameters and characteristics of the differential line drivers and line receivers are described in Table VHI. ⁇ Functionally, the driver transfers the logic level on the input directly to a positive output, and the inverse of the input to a negative output. The delay from input to outputs is well-matched to the differential line which is driven differentially. In most implementations, the voltage swing on the outputs is less than the swing on the input to minimize power consumption and electromagnetic emissions. Table VHI presents a minimum voltage swing to be around 0.5V. However, other values can be used, as would be known by those skilled in the art, and the inventors contemplate a smaller value in some embodiments, depending on design constraints. [00609] The differential line receivers have the same characteristic as a high-speed voltage comparator. In FIG.
• the input without the bubble is the positive input and the input with the bubble is the negative input.
• the output is a logic one if: (Vinput+) - (Vinput-) is greater than zero.
• Another way to describe this is a differential amplifier with very large (virtually infinite) gain with the output clipped at logic 0 and 1 voltage levels.
• a host controller 4202 and a client or display controller 4204 are shown transferring packets over the communication link 4206.
• the host controller employs a series of three drivers 4210, 4212, and 4214 to receive the host DATA and STB signals to be transferred, as well as to receive the client Data signals to be transferred.
• the driver responsible for passage of the host DATA employs an enable signal input to allow activation of the communication link generally only when transfer from the host to the client is desired. Since the STB signal is formed as part of the transfer of data, no additional enable signal is employed for that driver (4212).
• the outputs of each of the DATA and STB drivers are connected to termination impedances or resistors 4216a, 4216b, 4216c, and 4216d, respectively.
• Termination resistors 4216a and 4216b will also act as impedances on the input of the client side receiver 4220 for the STB signal processing while additional termination resistors 4216e and 4216f are placed in series with resistors 4216c and 4216d, respectively on the input of the client data processing receiver 4222.
• a sixth driver 4226 in the client controller is used to prepare the data signals being transferred from the client to the host, where driver 4214, through termination resistors 4216c and 4216d, on the input side, processes the data for transfer to the host for processing.
• Two additional resistors 4218a and 4218b are placed between the termination resistors and ground and a voltage source 4220, respectively, as part of the hibernation control discussed elsewhere.
• the voltage source is used to drive the transfer lines to the high or low levels previously discussed to manage the flow of data.
• the above drivers and impedances can be formed as discrete components or as part of a circuit module, or an application specific integrated circuit (ASIC) which acts as a more cost effective encoder or decoder solution.
• ASIC application specific integrated circuit
• the MDDIJPwr acts as the reference ground and the power supply return path or signal for the display device.
• the MDDIJPwr signal acts as the display device power supply which is driven by the host device In an exemplary configuration, for low power applications, the display device is allowed to draw up to 500 mA.
• the MDDIJPwr signal can be provided from portable power sources, such as but not limited to, a lithium-ion type battery or battery pack residing at the host device, and may range from 3.2 to 4.3 volts with respect to MDDI_Gnd.
• portable power sources such as but not limited to, a lithium-ion type battery or battery pack residing at the host device, and may range from 3.2 to 4.3 volts with respect to MDDI_Gnd.
• FIG. 43 The steps and signal levels employed by a client to secure service from the host and by the host to provide such service, are illustrated in FIG. 43.
• the first part of signals being illustrated shows a Link Shutdown Packet being transferred from the host and the data line is then driven to a logic zero state using the high-impedance bias circuit. No data is being transmitted by the client display, or host, which has its driver disabled. A series of strobe pulses for the MDDI_Stb signal line can be seen at the bottom, since MDDI_Stb is active during the Link Shutdown Packet.
• the MDDI_Stb signal line changes to a logic-zero level as well. This represents the termination of the last signal transfer or service from the host, and could have occurred at any time in the past, and is included to show the prior cessation of service, and the state of the signals prior to service commencement. If desired, such as signal can be sent just to reset the communication link to the proper state without a 'known' prior communication having been undertaken by this host device.
• the signal output from the client is initially set at a logic level of zero.
• the client output is at a high impedance, and the driver is disabled.
• the client enables its driver and sends a service request to the host, which is a period of time, designated tservice, during which the line is driven to a logic one level.
• tservice a period of time
• a certain amount of time then passes or may be needed before the host detects the request, termed thost-detect, after which the host responds with a link startup sequence by driving the signal to a logic one level.
• the client de-asserts the request, and disables the service request driver so that the output line from the client goes to a zero logic level again.
• the MDDI_Stb signal is at a logic zero level.
• the host drives the host data output at the '1' level for a period termed trestart-high, after which the host drives the logic level to zero and activates MDDI_Stb for a period termed trestart-low, after which the first forward traffic begins with a Sub-Frame Header Packet, and the forward traffic packets are then transferred.
• the MDDI_Stb signal is active during the trestart-low period and the subsequent Sub-Frame Header Packet.
• Table VIQ shows representative times for the length of the various periods discussed above, and the relationship to exemplary minimum and maximum data rates, where: 1 •-bit Link Data Rate
• FIGS. 41 and 42 are well known, and the function of the elements in FIG. 42 is confirmed by the timing diagram in FIG. 43. Details about the series terminations and hibernation resistors that are shown in FIG. 42 were omitted from FIG. 41 because that information is unnecessary for a description of how to perform the Data-Strobe encoding and recover the clock from it.
• Table IX presents a tabular form of the minimum and maximum desired, versus typical times for certain signal transitions to occur.
• a DataO to DataO transition termed ttdd-(host-output)
• ttbit the minimum time is about ttbit-0.5 nsec
• the maximum is about ttbit+0.5 nsec.
• FIGS. 45 and 46 illustrate the presence of a delay in response that can occur when the host disables or enables the host driver, respectively.
• the host disables the line driver after the desired packets are forwarded, such as the Parameter CRC, Strobe Alignment, and All Zero packets illustrated in FIG. 45 as having been transferred.
• the state of the line does not necessarily switch from '0' to a desired higher value instantaneously, although this is potentially achievable with certain control or circuit elements present, but takes a period of time termed the host Driver Disable Delay period to respond. While it could occur virtually instantly such that this time period is 0 nanoseconds (nsec.) in length, it could more readily extend over some longer period with 10 nsec. being a desired maximum period length, which occurs during the Guard Time 1 or Turn Around 1 packet periods.
• FIG. 46 one sees the signal level change undergone when the host Driver is enabled for transferring a packet such as the Reverse Link Encapsulation Packet or the Round Trip Delay Measurement Packet.
• a packet such as the Reverse Link Encapsulation Packet or the Round Trip Delay Measurement Packet.
• the host driver is enabled and begins to drive a level, here '0', which value is approached or reached over a period of time termed the Host Driver Enable Delay period, which occurs during the Driver Re-enable period, prior to the first packet being sent.
• FIGS.47, and 48 The switching characteristics and timing relationships for the data and strobe signals used to transfer data on the reverse link from the client driver output are shown in FIGS.47, and 48. The typical times for certain signal transitions are discussed below.
• FIG. 47 illustrates the relationship at the host receiver input between the timing of the data being transferred and the leading and trailing edges of the strobe pulses. That is, what is referred to as the set-up time for the rising or leading edge of the strobe signals, tsu-sr and the set-up time for the trailing or falling edge of the strobe signals, tsu-sf.
• a typical length of time for these set-up periods is on the order of a minimum of 8 nanoseconds.
• FIG. 48 illustrates the switching characteristics and corresponding client output delay developed by the reverse data timing.
• FIG. 48 one can see the relationship between the timing of the data being transferred and the leading and trailing edges of the strobe pulses accounting for induced delay. That is, what is referred to as the propagation delay between the rising or leading edge of the strobe signals and the data (valid), tpd-sr, and the propagation delay between the data and the trailing or falling edge of the strobe signals, tpd-sf.
• a typical maximum length of time for these propagation delay periods is on the order of 8 nanoseconds.
• Packets being transferred over a MDDI link are dispatched very rapidly, typically at a rate on the order of 300 Mbps or more, such as 400 Mbps, although lower rates are certainly accommodated, as desired.
• This type of bus or transfer link speed is too great for currently commercially available (economical) general-purpose microprocessors or the like to control. Therefore, a practical implementation to accomplish this type of signal transfer is to utilize a programmable state machine to parse the input packet stream to produce packets that are transferred or redirected to the appropriate audio-visual subsystem for which they are intended.
• Such devices are well known and use circuits generally dedicated to a limited number of operations, functions, or states to achieve a desired high speed or very high speed operation.
• General purpose controllers, processors, or processing elements can be used to more appropriately act upon or manipulate some information such as control or status packets, which have lower speed demands.
• the state machine should pass them through a data buffer or similar processing element to the general-purpose processor so the packets can be acted upon to provide a desired result (effect) while the audio and visual packets are transferred to their appropriate destination for action.
• the states or state machine discussed below might also be implemented using software control of such devices, typically as programs stored on a storage element or media.
• the general purpose processor function can be realized in some embodiments by taking advantage of the processing power, or excess cycles available for, microprocessors (CPUs) in computer applications, or controllers, processors, digital signal processors (DSPs), specialized circuits, or ASICs found in wireless devices, in much the same manner as some modems or graphics processors utilize the processing power of CPUs found in computers to perform some functions and reduce hardware complexity and costs.
• CPUs microprocessors
• DSPs digital signal processors
• specialized circuits or ASICs found in wireless devices
• the display signal processing is synchronized with the forward link channel timing. That is, signals arriving at the display and the display circuits need to be substantially time synchronized for proper signal processing to occur.
• a high level diagram of states achieved by signal processing steps or a method by which such a synchronization can be ' implemented is presented in the illustration of FIG.49. In FIG.
• the possible forward link synchronization "states" for a state machine 4900 are shown being categorized as one ASYNC FRAMES STATE 4904, two ACQUIRING SYNC STATES 4902 and 4906, and three IN-SYNC STATES 4908, 4910, and 4912.
• the display or client such as a presentation device, starts in a pre-selected "no sync" state, and searches for a unique word in the first sub-frame header packet that is detected. It is to be noted that this no sync state represents the minimum communication setting or "fall-back" setting in which a Type I interface is selected.
• the display saves the sub-frame length field.
• sync state processing proceeds accordingly to a state 4904 labeled here as the "async frames" state, which indicates that synchronization has not yet been achieved. This step in the processing is labeled as having encountered cond 3, or condition 3, in FIG. 49. Otherwise, if the frame length is greater than zero, then the sync state processing proceeds to a state 4906 where the interface state is set as "found one sync frame.” This step in the processing is labeled as encountering cond 5, or condition 5, in FIG. 49. In addition, if the state machine sees a frame header packet and good CRC determination for a frame length greater than zero, processing proceeds to the "found one sync frame” state. This is labeled as meeting cond 6, or condition 6, in FIG.49.
• the interface can be configured to accommodate a certain number of "sync errors" prior to deciding that synchronization is lost and returning to the "NO SYNC FRAME" state.
• FIG. 49 once the state machine has reached the "IN-SYNC STATE" and no errors are found, it is continuously encountering a cond 1 result, and remains in the "IN-SYNC” state. However once one cond 2 result is detected, processing changes the state to a "one- sync-error" state 4910.
• the sub-frame length in the sub-frame Header Packet may be set to zero to indicate that the host will transmit only one sub-frame before the link is shut down, and the MDD interface is placed in or configured into an idle hibernation state. In this case, the display must immediately receive packets over the forward link after detecting the sub-frame Header Packet because only a single sub-frame is sent before the link transitions to the idle state. In normal or typical operations, the sub-frame length is non-zero and the display only processes forward link packets while the interface is in those states collectively shown as "IN-SYNC" states in FIG. 49.
• the time required for a display to synchronize to the forward link signal is variable depending on the sub-frame size and the forward link data rate.
• the likelihood of detecting a "false copy" of the unique word as part of the random, or more random, data in the forward link is greater when the sub-frame size is larger.
• the ability to recover from a false detection is lower, and the time taken to do so is longer, when a forward link data rate is slower.
• the host configures the forward link to operate at or below a minimum required, or desired, data rate of 1 Mbps, and configures the sub-frame length and media-frame rate appropriately for a given application. That is, both the forward and reverse links begin operation using the Type-I interface. These parameters are generally only going to be used temporarily while the host determines the capability or desired configuration for the client display (or other type of client device).
• the host sends or transfers a sub-frame Header Packet over the forward link followed by a Reverse Link Encapsulation Packet which has bit '0' of the Request Flags set to a value of one (1), in order to request that the display or client responds with a Display Capability Packet.
• the display acquires synchronization on (or with) the forward link, it sends a Display Capability Packet and a Display Request and Status Packet over the reverse link or channel.
• the host examines the contents of the Display Capability Packet in order to determine how to reconfigure the link for optimal or a desired level of performance.
• the host examines the Protocol Version and Minimum Protocol Version fields to confirm that the host and display use versions of the protocol that are compatible with each other.
• the protocol versions generally remain as the first two parameters of the display capability Packet so that compatibility can be determined even when other elements of the protocol might not be compatible or completely understood as being compatible.
• the packet processor state machine ensures that the CRC checker is controlled appropriately or properly. It also increments a CRC error counter when a CRC comparison results in one or more errors being detected, and it resets the CRC counter at the beginning of each sub-frame being processed.
• the system or client starts with state machine 5000 in the pre-selected "no sync" state 4902, as in FIG. 49.
• the first state change for changing states from the no-sync condition 4902 is in condition 64 which is the discovery of the sync pattern.
• condition 64 is the discovery of the sync pattern.
• the state of the packet processor state machine can be changed to the in-sync state 4908.
• a sync error, condition 62 will cause the state machine to shift to state 4910, and a second occurrence to state 4912.
• This new interface implementation allows the MDD interface link to recognize synchronization failures much more quickly, and, therefore, to recover from them more quickly, as well.
• the client should also add or utilize a sub-frame counter.
• the client checks for the presence of the unique word at the time it is expected to arrive or occur in a signal. If the unique word does not occur at the correct time, the client can recognize that a synchronization failure has occurred much more quickly than if it had to wait several (here three) packet times or periods that were greater than a sub-frame length. If the test for the unique word indicates it is not present, in other words that the timing is incorrect, then the client can immediately declare a link loss of synchronization and move to the no-sync state. The process of checking for the proper unique word presence, adds a condition 65 (cond 65) to the state machine saying that the unique word is incorrect.
• condition 65 cond 65
• This change uses an additional counter or counting function in the client core to count sub-frame length.
• a count down function is used and the transfer of any packet that was currently being processed is interrupted to check for the sub-frame unique word if the counter has expired.
• the counter can count up, with the count being compared to a desired maximum or particular desired value, at which point the current packet is checked. This process protects the client from decoding packets that are incorrectly received on the client with extraordinarily long packet lengths. If the sub-frame length counter needed to interrupt some other packet that was being decoded, a loss of synchronization can be determined since no packet should cross a sub-frame boundary.
• Forward link packets are generally processed according to the exemplary processing listed in Table XII below.
• the MDDI_Stb signal pair toggles to create a periodic data clock at half the forward link data rate. This occurs because the host link controller generates the MDDI_Stb signal that corresponds to the MDDIJDataO signal as if it were sending all zeroes.
• the MDDI_Stb signal is transferred from the host to a client where it is used to generate a clock signal for transferring reverse link data from the display, with which reverse data is sent back to the host.
• a series of delay values 1.5 nsec, 8.0 nsec, 2.5 nsec, 2.0 nsec, 1.0 nsec, 1.5 nsec, 8.0 nsec, and 2.5 nsec, are shown near processing portions for the Stb+/- generation, cable transfer-to-display, display receiver, clock generation, signal clocking, Data0+/- generation, cable transfer-to-host, and host receiver stages, respectively.
• the Reverse Rate Divisor makes it possible for one bit time on the reverse link to span multiple cycles of the MDDI_Stb signal. This means that the reverse link data rate is less than the forward link rate.
• the actual length of signal delays through the interface may differ depending on each specific host-client system or hardware being used. Although not required, each system can generally be made to perform better by using the Round Trip Delay Measurement Packet to measure the actual delay in a system so that the Reverse Rate Divisor can be set to an optimum value.
• a round-trip delay is measured by having the host send a Round Trip Delay Measurement Packet to the display.
• the display responds to this packet by sending a sequence of ones back to the host inside of, or during, a pre-selected measurement window in that packet called the Measurement Period field. The detailed timing of this measurement was described previously.
• the round-trip delay is used to determine the rate at which the reverse link data can be safely sampled.
• the round-trip delay measurement consists of determining, detecting, or counting the number of forward link data clock intervals occurring between the beginning of the Measurement Period field and the beginning of the time period when the Oxff, Oxff, 0x00 response sequence is received back at the host from the client. Note that it is possible that the response from the client could be received a small fraction of a forward link clock period before the measurement count was about to increment. If this unmodified value is used to calculate the Reverse Rate Divisor it could cause bit errors on the reverse link due to unreliable data sampling. An example of this situation is illustrated in FIG.
• signals representing MDDIJData at host, MDDI_Stb at host, forward link data clock inside the host, and a Delay Count are illustrated in graphical form.
• the response sequence was received from the display a fraction of a forward link clock period before the Delay Count was about to increment from 6 to 7. If the delay is assumed to be 6, then the host will sample the reverse data just after a bit transition or possibly in the middle of a bit transition. This could result in erroneous sampling at the host. For this reason, the measured delay should typically be incremented by one before it is used to calculate the Reverse Rate Divisor.
• the reverse link data is sampled by the host on the rising edge of the Reverse Link Clock.
• the counters are initialized so that the first rising edge of the Reverse Link Clock occurs at the beginning of the first bit in the Reverse Link Packets field of the Reverse Link Encapsulation packet. This is illustrated, for the example given below, in FIG. 52.
• the counters increment at each rising edge of the MDDI_Stb signal, and the number of counts occurring until they wrap around is set by the Reverse Rate Divisor parameter in the Reverse Link Encapsulation Packet.
• the reverse link rate is one half of the forward link rate divided by the Reverse Rate Divisor. For example, if the forward link rate is 200 Mbps and the Reverse Rate Divisor is 4 then the reverse link data rate is expressed as:
• FIG. 52 An example showing the timing of the MDDIJDataO and MDDI_Stb signal lines in a Reverse Link Encapsulation Packet is shown in FIG. 52, where the packet parameters used for illustration have the values:
• the first reverse link packet returned from the display is the Display Request and Status Packet having a Packet Length of 7 and a packet type of 70.
• This packet begins with the byte values 0x07, 0x00, 0x46, ... and so forth. However, only the first byte (0x07) is visible in FIG. 52.
• This first reverse link packet is time-shifted by nearly one reverse link clock period in the figure to illustrate an actual reverse link delay. An ideal waveform with zero host to display round-trip delay is shown as a dotted-line trace.
• the MS byte of the Parameter CRC field is transferred, preceded by packet type, then the all zero field.
• the strobe from the host is switching from one to zero and back to one as the data from the host changes level, forming wider pulses. As the data goes to zero, the strobe switches at the higher rate, only the change in data on the data line causes a change near the end of the alignment field. The strobe switches at the higher rate for the remainder of the figure due to the fixed 0 or 1 levels of the data signal for extended periods of time, and the transitions falling on the pulse pattern (edge).
• the reverse link clock for the host is at zero until the end of the Turn Around 1 period, when the clock is started to accommodate the reverse link packets.
• the arrows in the lower portion of the figure indicate when the data is sampled, as would be apparent from the remainder of the disclosure.
• the first byte of the packet field being transferred (here 11000000) is shown commencing after Turn Around 1, and the line level has stabilized from the host driver being disabled.
• the delay in the passage of the first bit, and as seen for bit three, can bee seen in the dotted lines for the Data signal.
• a first region 5302 corresponds to an area of safe operation
• a second region 5304 corresponds to an area of marginal performance
• a third region 5306 indicates settings that are unlikely to function properly.
• the Turn Around 1 field in the Reverse Link Encapsulation Packet and the Guard Time 1 field in the Round Trip Delay Measurement Packet designate values for lengths of time that allow for the host interface drivers to be disabled before the display interface drivers are enabled.
• Turn Around 2 and Guard Time 2 fields provide time values which allow the display drivers to be disabled before the host drivers are enabled.
• the Guard Time 1 and Guard Time 2 fields are generally filled with pre-set or pre-selected values for lengths that are not meant to be adjusted. Depending on the interface hardware being used, these values may be developed using empirical data and adjusted in some instances to improve operation.
• Interface Type Factor is 1 for Type-I, 2 for Type-H, 4 for Type-UI, and 8 for Type-IV. [00665] Combining the two equations from above, one can see that the Interface Type Factor term cancels out, and Turn Around 1 is defined as:
• a 1500 Mbps Type-UI forward link would use a Turn Around 1 delay of:
• the timing margin improves from the point in time when the host is disabled to the time the display is enabled.
• the factors that determine the length of time generally used for Turn Around 2 are the forward link data rate, the maximum disable time of the MDDIJData drivers in the display, and the round-trip delay of the communication link.
• the calculation of the time required to disable the display driver is essentially the same as that for the host driver discussed above, and is defined according to the relationship:
• ForwardLinkDataRate Clocks _to _disable ⁇ A2 DisplayDriverDisableDelay ⁇ InterfaceTypeFacto ⁇ FWD and the allowed value range for Turn Around 2 is expressed as:
• the previous approach to the timing of the reverse link is configured such that the number of clock cycles is counted from the last bit of the Guard Time 1 of a reverse timing packet until the first bit is sampled on the rising edge of an IO clock. That is the clock signal(s) used to time the inputs and outputs for the MDD interface.
• FIG. 64 Examples of the arriving reverse bit and how that bit would look for various reverse rate divisors, is illustrated in FIG. 64, along with a number of clock cycles that have occurred since the last bit of Guard Time 1.
• the optimal sampling point for a reverse rate divisor of one is a clock cycle edge labeled 'b', as that is the only rising edge occurring within the period of the reverse bit.
• the optimal sampling point is probably still clock cycle leading edge 'b' as cycle edge 'c' is closer to a bit edge than 'b'.
• the optimal sampling point is probably clock cycle edge 'd', as it is closer to the back edge of the reverse bit where the value has probably stabilized.
• the optimal sampling point for a reverse rate divisor of one is sampling point clock cycle edge 'a', as that is the only rising edge within the reverse bit time period.
• edge 'b' For a reverse rate divisor of two. the optimal sampling point is edge 'b', and for a reverse rate divisor of four the optimal sampling point is edge 'c'.
• the host can use this technique to find the number of rising clock edges before the rising data edge of the timing packet data is observed on the data line. It can then decide, based on whether the edge occurs between a rising and falling edge or between a falling and rising edge, and what the reverse rate divisor is, how many additional clock cycles to add to a number counter, to reasonably ensure that the bit is always sampled as close to the middle as possible.
• the host can "explore" various reverse rate divisors with the client to determine if a particular reverse rate divisor will work.
• the host (and client) can start with a divisor of one and check the CRC of the reverse status packet received from the client to determine if this reverse rate functions appropriately to transfer data. If the CRC is corrupt, there is probably a sampling error, and the host can increase the reverse rate divisor and try to request a status packet again. If the second requested packet is corrupt, the divisor can be increased again and the request made again. If this packet is decoded correctly, this reverse rate divisor can be used for all future reverse packets.
• This method is effective and useful because the reverse timing should not change from the initial round trip timing estimate. If the forward link is stable, the client should continue to decode forward link packets even if there are reverse link failures. Of course, it is still the responsibility of the host to set a reverse link divisor for the link, since this method does not guarantee a perfect reverse link. In addition, the divisor will depend primarily on the quality of the clock that is used to generate an IO clock. If that clock has a significant amount of jitter, there is a greater possibility of a sampling error. This error probability increases with the amount of clock cycles in the round trip delay.
• This implementation appears to work best for Type-I reverse data, but may present problems for Type-II through Type-IV reverse data due to the skew between data lines potentially being too great to run the link at the rate that works best for just one data pair. However, the data rate probably does not need to be reduced to the previous method even with Type-U through Type-IV for operation.
• This method may also work best if duplicated on each data line to select the ideal or an optimal clock sample location. If they are at the same sample time for each data pair, this method would continue to work. If they are at different sample periods, two different approaches may be used. The first is to select an desired or more optimized sample location for each data point, even if it is not the same for each data pair.
• the host can then reconstruct the data stream after sampling all of the bits from the set of data pairs: two bits for Type-U, four bits for Type-UI, and eight bits for Type-IV.
• the other option is for the host to increase the reverse rate divisor such that the data bits for every data pair can be sampled at the same clock edge.
• Delay skew on the forward link between the MDDIJData pairs and MDDI_Stb can limit the maximum possible data rate unless delay skew compensation is used.
• the differences in delay that cause timing skew are due to the controller logic, the line drivers and receivers, and the cable and connectors as outlined below.
• FIG. 57 A typical interface circuit similar to that shown in FIG. 41, is shown in FIG. 57 for accommodating a Type-I interface link.
• exemplary or typical values for propagation delay and skew are shown for each of several processing or interface stages of an MDDI Type-I forward link. Skew in the delay between MDDI_Stb and MDDIJDataO causes the duty-cycle of the output clock to be distorted. Data at the D input of the receiver flip-flop (RXFF) stage using flip-flops 5728, 5732, must change slightly after the clock edge so that it can be sampled reliably.
• the figure shows two cascaded delay lines 5732a and 5732b being used to solve two different problems with creating this timing relationship. In the actual implementation these may be combined into a single delay element.
• the total delay skew that is significant generally arises or comes from the sum of the skew in the following stages: transmitter flip-flop (TXFF) with flip-flops 5704, 5706; transmitter driver (TXDRVR) with drivers 5708, 5710; the CABLE 5702; receiver line receiver (RXRCVR) with receivers 5722, 5724; and receiver XOR logic (RXXOR).
• Delay 1 5732a should match or exceed the delay of the XOR gate 5736 in the RXXOR stage which is determined by the relationship: t PD - min( Delay 1) > t PD -max( XOR )
• Delay2 The purpose or function of Delay2 is to compensate for the hold-time of the RXFF flip-flop according to the relationship:
• the data may change between two bit periods, n and n+1, very close to the time where bit n+1 is clocked into the receiver flip-flop.
• the maximum data rate (minimum bit period) of an MDDI Type-I link is a function of the maximum skew encountered through all the drivers, cable, and receivers in the MDDI link plus the total data setup into the RXFF stage.
• t SKEW-max.(LINK) * SKEW-raax(TXFF) " * " * SKEW-max(TXDRVR) " " * SKEW-msx. ⁇ CABLE) " * " * SKEW-max(RXRCVR) and the minimum bit period is given by:
• FIG. 59 A typical interface circuit similar to that shown in FIGS. 41 and 57, is shown in FIG. 59 for accommodating Type-U, HI, and IV interface links. Additional elements are used in the TXFF (5904), TXDRVR (5908), RXRCVCR (5922), and RXFF (5932, 5928, 5930) stages to accommodate the additional signal processing.
• TXFF TXDRVR
• RXRCVCR 5922
• RXFF 5932, 5928, 5930
• FIG. 59 exemplary or typical values for propagation delay and skew are shown for each of several processing or interface stages of an MDDI Type-U forward link.
• the maximum link speed is determined by the minimum allowable bit period. This is most affected when MDDIJDataX arrives as late as possible. In that case, the minimum allowable cycle time is given by:
• Physical connections useful for implementing an interface according to the present invention can be realized using commercially available parts such as part number 3260- 8S2(01) as manufactured by Hirose Electric Company Ltd. on the host side, and part number 3240-8P-C as manufactured by Hirose Electric Company Ltd. on the display device side.
• An exemplary interface pin assignment or "pinout" for such connectors used with a Type-I/Type-II interfaces is listed in Table XHI, and illustrated in FIG. 61.
• the shield is connected to the MDDI_Gnd in the host interface, and a shield drain wire in the cable is connected to the shield of the display connector. However, the shield and drain wire are not connected to the circuit ground inside of a display.
• Interconnection elements or devices are chosen or designed in order to be small enough for use with mobile communication and computing devices, such as PDAs and wireless telephones, or portable game devices, without being obtrusive or unaesthetic in comparison to relative device size. Any connectors and cabling should be durable enough for use in the typical consumer environment and allow for small size, especially for the cabling, and relatively low cost.
• the transfer elements should accommodate data and strobe signals that are differential NRZ data having a transfer rate up to around 450 Mbps for Type I and Type II and up to 3.6 Gbps for the 8-bit parallel Type IV version.
• connection elements For internal mode applications there are either no connectors in the same sense for the conductors being used or such connection elements tend to be very miniaturized.
• One example is zero insertion force "sockets" for receiving integrated circuits or elements housing either the host or client device.
• the host and client reside on printed circuit boards with various interconnecting conductors, and have "pins" or contacts extending from housings which are soldered to contacts on the conductors for interconnection of integrated circuits.
• FIGS. 54A and 54B A summary of the general steps undertaken in processing data and packets during operation of an interface using embodiments of the invention is shown in FIGS. 54A and 54B, along with an overview of the interface apparatus processing the packets in FIG. 55.
• the process starts in a step 5402 with a determination as to whether or not the client and host are connected using a communication path, here a cable. This can occur through the use of periodic polling by the host, using software or hardware that detects the presence of connectors or cables or signals at the inputs to the host (such as is seen for USB interfaces), or other known techniques.
• a client Once a client is connected to the host, or visa versa, or detected as being present, either the client or the host sends appropriate packets requesting service in steps 5404 and 5406.
• the client could send either Display Service Request or Status packets in step 5404. It is noted that the link, as discussed above, could have been previously shut down or be in hibernation mode so this may not be a complete initialization of the communication link that follows.
• the client Once the communication link is synchronized and the host is trying to communicate with the client, the client also provides a Display Capabilities packet to the host, as in step 5408. The host can now begin to determine the type of support, including transfer rates, the client can accommodate.
• the host and client also negotiate the type (rate/speed) of service mode to be used, for example Type I, Type U, Type II, and so forth, in a step 5410.
• the host can begin to transfer information.
• the host may use Round Trip Delay Measurement Packets to optimize the timing of the communication links in parallel with other signal processing, as shown in step 5411.
• Sub-Frame Header Packet shown being transferred in step 5412, followed by the type of data, here video and audio stream packets, and filler packets, shown being transferred in step 5414.
• the audio and video data will have been previously prepared or mapped into packets, and filler packets are inserted as needed or desired to fill out a required number of bits for the media frames.
• the host can send packets such as the Forward Audio Channel Enable Packets to activate sound devices.
• the host can transfer commands and information using other packet types discussed above, here shown as the transfer of Color Map, Bit Block Transfer or other packets in step 5416.
• the host and client can exchange data relating to a keyboard or pointing devices using the appropriate packets.
• one of several different events can occur which lead to the host or client desiring a different data rate or type of interface mode.
• a computer or other device communicating data could encounter loading conditions in processing data that causes a slow down in the preparation or presentation of packets.
• a display receiving the data could change from a dedicated AC power source to a more limited battery power source, and either not be able to transfer in data as quickly, process commands as readily, or not be able to use the same degree of resolution or color depth under the more limited power settings.
• a restrictive condition could be abated or disappear allowing either device to transfer data at higher rates. This being more desirable, a request can be made to change to a higher transfer rate mode.
• step 5420 the host sends Interface Type Handoff Request Packets to the client requesting a handoff to another mode, the client sends Interface Type Acknowledge Packets confirming a change is sought, and the host sends Perform Type Handoff Packets to make the change to the specified mode.
• the client and host can also exchange packets relating to data intended for or received from pointing devices, keyboards, or other user type input devices associated primarily with the client, although such elements may also be present on the host side. These packets are typically processed using a general processor type element and not the state machine (5502). In addition, some of the commands discussed above will also be processed by the general processor. (5504, 5508)
• step 5422 After data and commands have been exchanged between the host and client, at some point a decision is made as to whether or not additional data is to be transferred or the host or client is going to cease servicing the transfer. This is shown in step 5422. If the link is to enter either a hibernation state or be shut down completely, the host sends a Link Shutdown packet to the client, and both sides terminate the transfer of data.
• the packets being transferred in the above operations processing will be transferred using the drivers and receivers previously discussed in relation to the host and client controllers.
• These line drivers and other logic elements are connected to the state machine and general processors discussed above, as illustrated in the overview of FIG. 55.
• a state machine 5502 and general processors 5504 and 5508 may further be connected to other elements not shown such as a dedicated USB interface, memory elements, or other components residing outside of the link controller with which they interact, including, but not limited to, the data source, and video control chips for view display devices.
• the processors, and state machine provide control over the enabling and disabling of the drivers as discussed above in relation to guard times, and so forth, to assure efficient establishment or termination of communication link, and transfer of packets.
• Video data buffering requirements are different for moving video images compared to computer graphics. Pixel data is most often stored in a local frame buffer in the client so the image on the display can be refreshed locally.
• MDDI Video Stream Packets update the buffers according to the structure or methodology of: when Display Update Bits equal to '01', pixel data is written to the buffer specified by currentj ⁇ ll; when Display Update Bits equal to '00', pixel data is written to the buffer specified by just_filled; and when Display Update Bits equal to "11", pixel data is written to all buffers.
• the display is refreshed from the buffer specified by the being_displayed pointer. After the display refreshes the last pixel in one frame refresh epoch and before it begins to refresh the first pixel in the next frame refresh epoch the display update process performs the operation of seting beingjrefreshed equal to just_filled;
• the Video Stream Packet contains a pair of Display Update Bits that specify the frame buffer where the pixel data shall be written.
• the Display Capability Packet has three additional bits that indicate which combinations of the Display Update Bits are supported in the client.
• Display Update Bit combinations "00" and "11" support this mode of operation by causing the pixel data to be written to the frame buffer being displayed or to both frame buffers.
• FIG. 92 illustrates how video images are displayed using a pair of frame buffers when video data is transmitted over the MDDI link with the Display Update Bits equal to "01". After a media-frame boundary is detected on the MDDI link, the display refresh process will begin refreshing from the next frame buffer when the refresh process for the frame currently being refreshed is completed.
• FIG 92 An important assumption related to FIG 92 is that the image is received from the host as a continuous stream of pixels that are transmitted in the same order that the client uses to read the pixels from the frame buffer to refresh the display (usually upper-left, reading row by row, to the bottom-right corner of the screen. This is an important detail in the cases where the Display Refresh and Image Transfer operations reference the same frame buffer. [00719] It is necessary for the display refresh frame rate to be greater than the image transfer frame rate to avoid displaying partial images.
• FIG. 93 shows how image fragmentation can occur with a slow display refresh rate, that is the display refresh is slower than the image transfer.
• the video pixel data might occupy a small portion of a media-frame. This could be significant in situations where the display refresh operation and the image transfer reference the same frame buffer. These situations are shown by a cross-hatched shading in FIG. 94, where the pixels read from the buffer to refresh the display might be the pixels written to the buffer two frames ago, or they may correspond to the frame immediately being written to the same frame buffer.
• any-size video window Image frame 1 buffer A frame 2, buffer B frame 3, buffer C frame 4, buffer A frame 5, buffer B frame 6, buffer C Transfer «% — ⁇ — — — — — ⁇ ⁇ — — — — — — — — — - ⁇ — — ⁇ —
• the Packet Processing Delay Parameters Packet uses a table-lookup function to calculate the predicted delay to process certain commands in the client. Values in the table increase in a logarithmic fashion to provide a very wide dynamic range of delay values.
• An exemplary table of delay values useful for implementing embodiments of the invention is found in Table XX below, with corresponding index values versus delay values. Tabel XX (add whole new table)
• the delay is computed by performing a table lookup using the specified parameter as an index into the table. This means a delay is equal to PacketProcessingTable(index). For example: if one of the parameters from the Delay Parameters List Item is an 8-bit value equal to 134, then the delay is equal to PacketProcessingTable(134) which is 16 ⁇ sec. The value 255 indicates that the command completion time cannot be determined by calculation, and that the host must check the Graphics Busy Flags in the Display Request and Status Packet or MCCS VCP Control Parameter B7h. [00726] In some cases this delay is multiplied by the height, width, or number of pixels in the destination image and added to other delays to compute the overall packet processing delay.
• the current protocol version does not appear to directly support multiple client devices.
• most packets contain a reserved Client ID field that can be used to address specific client devices in a system with multiple clients.
• this client ID or these client IDs are set to be zero.
• the sub-frame header packet also contains a field to indicate whether or not the host supports a multiple client system. Therefore, there is a manner in which multiple client devices would likely be connected and addressed in future applications of the MDD interface or protocol to aid system designers to plan for future compatibility with multiple client hosts and clients.
• the Pixel Data Attributes field (2 byte) has a series of bit values that are interpreted as follows. Bits 1 and 0 select how the display pixel data is routed. For bit values of '11' data is displayed to or for both eyes, for bit values '10', data is routed only to the left eye, and for bit values '01', data is routed only to the right eye, and for bit values of '00' the data is routed to an alternate display as may be specified by bits 8 through 11 discussed below.
• Bit 2 indicates whether or not the Pixel Data is presented in an interlace format, with a value of '0' meaning the pixel data is in the standard progressive format, and that the row number (pixel Y coordinate) is incremented by 1 when advancing from one row to the next.
• this bit has a value of T, the pixel data is in interlace format, and the row number is incremented by 2 when advancing from one row to the next.
• Bit 3 indicates that the Pixel Data is in alternate pixel format. This is similar to the standard interlace mode enabled by bit 2, but the interlacing is vertical instead of horizontal.
• Bit 3 is '0' the Pixel Data is in the standard progressive format, and the column number (pixel X coordinate) is incremented by 1 as each successive pixel is received.
• Bit 3 is '1' the Pixel Data is in alternate pixel format, and the column number is incremented by 2 as each pixel is received.
• Bit 4 indicates whether or not the Pixel data is related to a display or a camera, as where data is being transferred to or from an internal display for a wireless phone or similar device or even a portable computer, or such other devices as discussed above, or the data is being transferred to or from a camera built into or directly coupled to the device.
• Bit 4 is '0' the Pixel data is being transferred to or from a display frame buffer.
• Bit 4 is '1' Pixel data is being transferred to or from a camera or video device of some type, such devices being well known in the art.
• Bit 5 is used to indicate when the pixel data contains the next consecutive row of pixels in the display. This is considered the case when Bit 5 is set equal to '1'. When bit 5 is set to '1' then the X Left Edge, Y Top Edge, X Right Edge, Y Bottom Edge, X Start, and Y Start parameters are not defined and are ignored by the client. The Frame Sync Packet defines the next row to be the top row of the image.
• Bits 7 and 6 are Display Update Bits that specify a frame buffer where the pixel data is to be written. There more specific effects are discussed elsewhere. For bit values of '01' Pixel data is written to the offline image buffer. For bit values of '00' Pixel data is written to the image buffer used to refresh the display. For bit values of '11' Pixel data is written to all image buffers. The bit values or combination of '10' is treated as an invalid value or designation and Pixel data is ignored and not written to any of the image buffers. This value may have use for future applications of the interface. [00735] Bits 8 through 11 form a 4-bit unsigned integer that specifies an alternate display or display location where pixel data is to be routed.
• Bits 0 and 1 are equal to 00 in order for the display client to interpret bits 8 through 11 as an alternate display number. If bits 0 and 1 are not equal to 00 then bits 8 through 11 are set to zero. [00736] Bits 12 through 15 are reserved for future use and are generally set as zero
• the 2-byte X Start and Y Start fields specify the absolute X and Y coordinates of the point (X Start, Y Start) for the first pixel in the Pixel Data field.
• the 2-byte X Left Edge and Y Top Edge fields specify the X coordinate of the left edge and Y coordinate of the top edge of the screen window filled by the Pixel Data field, while the X Right Edge and Y Bottom Edge fields specify the X coordinate of the right edge, and the Y coordinate of the bottom edge of the window being updated.
• the Pixel Count field (2 bytes) specifies the number of pixels in the Pixel Data field below.
• the Parameter CRC field (2 bytes) contains a CRC of all bytes from the Packet Length to the Pixel Count.
• the Pixel Data field contains the raw video information that is to be displayed, and which is formatted in the manner described by the Video Data Format Descriptor field. The data is transmitted one "row" at a time as discussed elsewhere.
• the Pixel Data CRC field (2 bytes) contains a 16-bit CRC of only the Pixel Data. If a CRC verification of this value fails then the Pixel Data can still be used, but the CRC error count is incremented.
• the Audio Channel ID field (1 byte) uses an 8 bit unsigned integer value to identify a particular audio channel to which audio data is sent by the client device.
• the physical audio channels are specified in or mapped to physical channels by this field as values of 0, 1, 2, 3, 4, 5, 6, or 7 which indicate the left front, right front, left rear, right rear, front center, sub- woofer, surround left, and surround right channels, respectively.
• An audio channel ID value of 254 indicates that the single stream of digital audio samples is sent to both the left front and right front channels. This simplifies communications for applications such as where a stereo headset is used for voice communication, productivity enhancement apps are used on a PDA, or other applications where a simple User Interface generates warning tones. Values for the ID field ranging from 8 through 253, and 255 are currently reserved for use where new designs desire additional designations, as anticipated by those skilled in the art.
• the Reserved 1 field (1 byte) is generally reserved for future use, and has all bits in this field set to zero. One function of this field is to cause all subsequent 2 byte fields to align to a 16-bit word address and cause 4-byte fields to align to a 32-bit word address.
• the Audio Sample Count field (2 bytes) specifies the number of audio samples in this packet.
• the Bits Per Sample and Packing field contains 1 byte that specifies the packing format of audio data.
• the format generally employed is for Bits 4 through 0 to define the number of bits per PCM audio sample.
• Bit 5 then specifies whether or not the Digital Audio Data samples are packed.
• FIG. 12 illustrates the difference between packed and byte-aligned audio samples.
• a value of '0' for Bit 5 indicates that each PCM audio sample in the Digital Audio Data field is byte-aligned with the interface byte boundary, and a value of T indicates that each successive PCM audio sample is packed up against the previous audio sample. This bit is effective only when the value defined in bits 4 through 0 (the number of bits per PCM audio sample) is not a multiple of eight.
• Bits 7 through 6 are reserved for use where system designs desire additional designations and are generally set at a value of zero.
• the Audio Sample Rate field (1 byte) specifies the audio PCM sample rate.
• the format employed is for a value of 0 to indicate a rate of 8,000 samples per second (sps), a value of 1 indicates 16,000 sps., value of 2 for 24,000 sps, value of 3 for 32,000 sps, value of 4 for 40,000 sps, value of 5 for 48,000 sps, value of 6 for 11,025 sps, value of 7 for 22,050 sps, and value of 8 for 44,100 sps, respectively, with values of 9 through 255 being reserved for future use, so they are currently set to zero.
• the Parameter CRC field (2 bytes) contains a 16-bit CRC of all bytes from the Packet Length to the Audio Sample Rate. If this CRC fails to check appropriately, then the entire packet is discarded.
• the Digital Audio Data field contains the raw audio samples to be played, and is usually in the form of a linear format as unsigned integers.
• the Audio Data CRC field (2 bytes) contain a 16-bit CRC of only the Audio Data. If this CRC fails to check then the Audio Data can still be used, but the CRC error count is incremented.
• the 2-byte Stream ID Number field is used to identify a particular user defined stream.
• the contents of the Stream Parameters and Stream Data fields are typically defined by the MDDI equipment manufacturer.
• the 2-byte Stream Parameter CRC field contains a 16-bit CRC of all bytes of the stream parameters starting from the Packet Length to the Audio Coding byte. If this CRC fails to check then the entire packet is discarded. Both the Stream Parameters and Stream Parameter CRC fields may be discarded if not needed by an end application of the MDD interface, that is, they are considered optional.
• the 2-byte Stream Data CRC field contains a CRC of only the Stream Data.
• Use of the stream data contingent on the CRC being good generally requires that the stream data be buffered until the CRC is confirmed as being good. The CRC error count is incremented if the CRC does not check.
• the 2-byte hClient ID field contains information or values that are reserved for a Client ID, as used previously. Since this field is generally reserved for future use, the current value is set to zero, by setting the bits to '0'.
• the 2-byte Color Map Item Count field uses values to specify the total number of 3- byte color map items that are contained in the Color Map Data field, or the color map table entries that exist in the Color Map Data in this packet. In this embodiment, the number of bytes in the Color Map Data is 3 times the Color Map Item Count.
• the Color Map Item Count is set equal to zero to send no color map data. If the Color Map Size is zero then a Color Map Offset value is generally still sent but it is ignored by the display.
• the Color Map Offset field (4 bytes) specifies the offset of the Color Map Data in this packet from the beginning of the color map table in the client device.
• a 2-byte Parameter CRC field contains a CRC of all bytes from the Packet Length to the Audio Coding byte. If this CRC fails to check then the entire packet is discarded.
• the width of each color map location is a specified by the Color Map Item Size field, where in one embodiment the first bart specifies the magnitude of blue, the second part specifies the magnitude of green, and the third part specifies the magnitude of red.
• the Color Map Size field specifies the number of 3-byte color map table items that exist in the Color Map Data field. If a single color map cannot fit into one Video Data Format and Color Map Packet, then the entire color map may be specified by sending multiple packets with different Color Map Data and Color Map Offsets in each packet. The number of bits of blue, green, and red in each color map data item shall be the same as specified in the Color Map RGB Width field of the Display Capability Packet.
• a 2-byte Color Map Data CRC field contains a CRC of only the Color Map Data. If this CRC fails to check then the Color Map Data can still be used but the CRC error count is incremented.
• Each color map data item is to be transmitted in the order: blue, green, red, with the least significant bit of each component transmitted first.
• the individual red, green, and blue components of each color map item shall be packed, but each color map item (the least significant bit of the blue component) should be byte-aligned.
• Error! Reference source not found. shows an example of color map data items with 6 bits of blue, 8 bits of green, and 7 bits of red.
• the Color Map Item Size in the Color Map Packet is equal to 21, and the Color Map RGB Width field of the Display Capability Packet is equal to 0x0786.
• Color Map Data Formatting 6 bits of blue, 8 bits of green, 7 bits of red
• the Parameter CRC field (2 bytes) contains a 16-bit CRC of all bytes from the Packet Length to the Turn- Around Length. If this CRC fails to check then the entire packet is discarded.
• the Reverse Link Flags field (1 byte) contains a set of flags to request information from the display. If a bit (for example, Bit 0) is set to one then the host requests the specified information from the display using the Display Capability Packet. If the bit is zero then the host does not need the information from the display. The remaining bits (here Bits 1 through 7) are reserved for future use and are set to zero. However, more bits can be used as desired to set flags for the reverse link.
• the Reverse Rate Divisor field (1 byte) specifies the number of MDDI_Stb cycles that occur in relation to the reverse link data clock.
• the reverse link data clock is equal to the forward link data clock divided by two times the Reverse Rate Divisor.
• the reverse link data rate is related to the reverse link data clock and the Interface Type on the reverse link. For a Type I interface the reverse data rate equals the reverse link data clock, for Type ⁇ , Type HI, and Type IV interfaces the reverse data rates equal two times, four times, and eight times the reverse link data clock, respectively.
• the All Zerol field contains a group of bytes that is set equal to zero in value by setting the bits at a logic-zero level, and is used to ensure that all MDDI_Data signals are in the zero state prior to disabling the line drivers during the first Guard Time period, to allow reflected logic-one levels to dissipate prior to disabling the Host's line drivers during the Turn- Around 1 field.
• the length of the All Zero 1 field is greater than or equal to the number of forward link byte transmission times in the round-trip delay of the cable.
• the Turn- Around 1 Length field (1 byte) specifies the total number of bytes that are allocated for Turn- Around 1, establishing the first turn-around period.
• the number of bytes specified by the Turn-Around Length parameter are allocated to allow the MDDI Data line drivers in the Host to disable before the line drivers in the client are enabled.
• the host disable its MDDI_Data line drivers during bit 0 of Turn- Around 1 and the client enables its outputs and drives MDDIJDataO to a logic 0 during the last bit of Turn- Around 1.
• the MDDI_Stb signal behaves as though the Turn Around 1 period were all zeros.
• the recommended length of Turn- Around 1 is the number of bytes required for the MDDI_Data drivers in a host to have the outputs disabled. This is based on the output disable time discussed above, the forward link data rate, and the forward link Interface Type selection being used. A more complete description of the setting of Turn- Around 1 is given above.
• the All Zero 2 field contains a group of bytes that is set equal to zero in value by setting the bits at a logic-zero level, and is used to ensure that all MDDIJData signals are in the zero state to allow reflected logic-one levels to dissipate prior to disabling the host's line drivers during the Turn- Around 1 field.
• the length of the All Zero 2 field is greater than or equal to the number of forward link byte transmission times in the round-trip delay of the cable.
• the Turn- Around 2 Length field (1 byte) specifies the total number of bytes that are allocated for Turn-Around 2, for establishing a second turn-around period.
• the number of bytes is specified by the Turn-Around Length parameter are allocated to allow the MDDI Data line drivers in the client to disable before the line drivers in the host are enabled.
• the client disables its MDDIJData line drivers during bit 0 of Tum-Around 2 and the host enables its outputs and drives MDDIJDataO to a logic 0 during the last bit of Turn- Around 2.
• the MDDI_Stb signal behaves as though the MDDIJDataO were at a logic-zero level during the entire Turn Around 2 period.
• the recommended length of Tum-Around 2 is the number of bytes required for the MDDI_Data drivers in the Display to disable their outputs plus the round-trip delay. A description of the setting of Turn- Around 2 is given above.
• the Reverse Data Packets field contains a series of data packets being transferred from the client to a host. As stated earlier, Filler packets are sent to fill the remaining space that is not used by other packet types.
• the Driver Re-enable field uses 1 byte that is equal to logic-zero to ensure that all MDDIJData signals are re-enabled prior to the Packet Length Field of the next packet.
• the Protocol Version field uses 2 bytes to specify a protocol version used by the client.
• the initial version is set equal to zero
• the Minimum Protocol Version field uses 2 bytes to specify the minimum protocol version that the client can employ or interpret.
• the Display Data Rate Capability field (2 bytes) specifies the maximum data rate the display can receive on the forward link of the interface, and is specified in the form of megabits per second (Mbps).
• the Interface Type Capability field (1 byte) specifies the interface types that are supported on the forward and reverse links.
• Bit 0, Bit 1, or Bit 2 to select either a Type-U, Type- UI or Type-IV mode on the forward link, respectively, and Bit 3, Bit 4, or Bit 5 to select either a Type-U, Type-UI, or Type-IV mode on the reverse link, respectively; with Bits 6 and 7 being reserved and set to zero.
• the Bitmap Width and Height fields (2 bytes) specify the width and height of the bitmap in pixels.
• the Monochrome Capability field (1 byte) is used to specify the number of bits of resolution that can be displayed in a monochrome format. If a display cannot use a monochrome format then this value is set at zero. Bits 7 through 4 are reserved for future use and are, thus, set as zero. Bits 3 through 0 define the maximum number of bits of grayscale that can exist for each pixel. These four bits make it possible to specify values of 1 to 15 for each pixel. If the value is zero then monochrome format is not supported by the display. [00766] The Color Map Capability field (3 bytes) specifies the maximum number of table items that exist in the color map table in the display. If the display cannot use the color map format then this value is zero.
• the RGB Capability field (2 bytes) specifies the number of bits of resolution that can be displayed in RGB format. If the display cannot use the RGB format then this value is equal to zero.
• the RGB Capability word is composed of three separate unsigned values where: Bits 3 through 0 define the maximum number of bits of blue, Bits 7 through 4 define the maximum number of bits of green, and Bits 11 through 8 define the maximum number of bits of red in each pixel. Currently, Bits 15 through 12 are reserved for future use and are generally set to zero.
• the Y Cr Cb Capability field (2 bytes) specifies the number of bits of resolution that can be displayed in Y Cr Cb format. If the display cannot use the Y Cr Cb format then this value is set equal to zero.
• the Y Cr Cb Capability word is composed of three separate unsigned values where: Bits 3 through 0 define the maximum number of bits in the Cb sample, Bits 7 through 4 define the maximum number of bits in the Cr sample, Bits 11 through 8 define the maximum number of bits in the Y sample, and Bits 15 through 12 are currently reserved for future use and are set to zero.
• the Display Feature Capability Indicators field uses 4 bytes that contain a set of flags that indicate specific features in the display that are supported. A bit set to one indicates the capability is supported, and a bit set to zero indicates the capability is not supported. The value for Bit 0 indicates whether or not Bitmap Block Transfer Packet (packet type 71) is supported. The value for Bits 1, 2, and 3 indicate whether or not Bitmap Area Fill Packet (packet type 72), Bitmap Pattern Fill Packet (packet type 73), or Communication Link Data Channel Packet (packet type 74), respectively, are supported.
• the value for Bit 4 indicates whether or not the display has the capability to make one color transparent, while values for bits Bit 5 and 6 indicate if the display can accept video data or audio data in packed format, respectively, and the value for Bit 7 indicates if the display can send a reverse-link video stream from a camera.
• the value for Bits 11 and 12 indicate when the client is communicating either with a pointing device and can send and receive Pointing Device Data Packets, or with a keyboard and can send and receive Keyboard Data Packets, respectively. Bits 13 through 31 are currently reserved for future use or alternative designations useful for system designers and are generally set equal to zero.
• the Display Video Frame Rate Capability field (1 byte) specifies the maximum video frame update capability of the display in frames per second. A host may choose to update the image at a slower rate than the value specified in this field.
• the Audio Buffer Depth field (2 bytes) specifies the depth of the elastic buffer in a Display which is dedicated to each audio stream.
• the Audio Channel Capability field (2 bytes) contains a group of flags that indicate which audio channels are supported by the display (client). A bit set to one indicates the channel is supported, and a bit set to zero indicates that channel is not supported.
• the Bit positions are assigned to the different channels, for example Bit positions 0, 1, 2, 3, 4, 5, 6, and 7 indicate the left front, right front, left rear, right rear, front center, sub-woofer, surround left, and surround right channels, respectively. Bits 8 through 15 are currently reserved for future use, and are generally set to zero.
• a 2-byte Audio Sample Rate Capability field for the forward link, contains a set of flags to indicate the audio sample rate capability of the client device. Bit positions are assigned to the different rates accordingly, such as Bits 0, 1, 2, 3, 4, 5, 6, 7, and 8 being assigned to 8,000, 16,000, 24,000, 32,000, 40,000, 48,000, 11,025, 22,050, and 44,100 samples per second (SPS), respectively, with Bits 9 through 15 being reserved for future or alternative rate uses, as desired, so they are currently set to '0'. Setting a bit value for one of these bits to T indicates that that particular sample rate is supported, and setting the bit to '0' indicates that that sample rate is not supported.
• SPS samples per second
• the Minimum Sub-frame Rate field (2 bytes) specifies the minimum sub-frame rate in frames per second.
• the minimum sub-frame rate keeps the display status update rate sufficient to read certain sensors or pointing devices in the display.
• a 2-byte Mic Sample Rate Capability field for the reverse link, that contains a set of flags that indicate the audio sample rate capability of a microphone in the client device.
• a client device microphone is configured to minimally support at least an 8,000 sample per second rate. Bit positions for this field are assigned to the different rates with bit positions 0, 1, 2, 3, 4, 5, 6, 7, and 8, for example, being used to represent 8,000, 16,000, 24,000, 32,000, 40,000, 48,000, 11,025, 22,050, and 44,100 samples per second (SPS), respectively, with Bits 9 through 15 being reserved for future or alternative rate uses, as desired, so they are currently set to '0'.
• SPS samples per second
• the Content Protection Type field (2 bytes) contains a set of flags that indicate the type of digital content protection that is supported by the Display. Currently, bit position 0 is used to indicate when DTCP is supported and bit position 1 is used to indicate when HDCP is supported, with bit positions 2 through 15 being reserved for use with other protection schemes as desired or available, so they are currently set to zero.
• the Reverse Link Request field (3 byte) specifies the number of bytes the display needs in the reverse link in the next sub-frame to send information to the host.
• the CRC Error Count field (1 byte) indicates how many CRC errors have occurred since the beginning of the media-frame.
• the CRC count is reset when a sub-frame header packet with a Sub-frame Count of zero is sent. If the actual number of CRC errors exceeds 255 then this value generally saturates at 255.
• the Capability Change field uses 1 byte to indicate a change in the capability of the display. This could occur if a user connects a peripheral device such as a microphone, keyboard, or display, or for some other reason.
• Bits[7:0] are equal to 0 then the capability has not changed since the last Display Capability Packet was sent. However, when Bits[7:0] are equal to 1 to 255, the capability has changed.
• the Display Capability Packet is examined to determine the new display characteristics.
• the Window Upper Left Coordinate X Value and Y Value fields use 2 bytes each to specify the X and Y value of the coordinates of the upper left corner of the window to be moved.
• the Window Width and Height fields use 2 bytes each to specify the width and height of the window to be moved.
• the Window X Movement and Y Movement fields use 2 bytes each to specify the number of pixels that the window is to be moved horizontally and vertically, respectively. Typically, these coordinates are configured such that positive values for X cause the window to be moved to the right, and negative values cause movement to the left, while positive values for Y cause the window to be moved down, and negative values cause upward movement.
• Window Upper Left Coordinate X Value and Y Value fields use 2 bytes each to specify the X and Y value of the coordinates of the upper left corner of the window to be filled.
• the Window Width and Height fields (2 bytes each) specify the width and height of the window to be filled.
• the Video Data Format Descriptor field (2 bytes) specifies the format of the Pixel Area Fill Value. The format is the same as the same field in the Video Stream Packet.
• the Pixel Area Fill Value field (4 bytes) contains the pixel value to be filled into the window specified by the fields discussed above. The format of this pixel is specified in the Video Data Format Descriptor field.
• Window Upper Left Coordinate X Value and Y Value fields use 2 bytes each to specify the X and Y value of the coordinates of the upper left corner of the window to be filled.
• the Window Width and Height fields (2 bytes each) specify the width and height of the window to be filled.
• the Pattern Width and Pattern Height fields (2 bytes each) specify the width and height, respectively, of the fill pattern.
• the 2-byte Video Data Format Descriptor field specifies the format of the Pixel Area Fill Value.
• FIG. 11 illustrates how the Video Data Format Descriptor is coded. The format is the same as the same field in the Video Stream Packet.
• the Parameter CRC field (2 bytes) contains a CRC of all bytes from the Packet Length to the Video Format Descriptor. If this CRC fails to check then the entire packet is discarded.
• the Pattern Pixel Data field contains raw video information that specifies the fill pattern in the format specified by the Video Data Format Descriptor. Data is packed into bytes, and the first pixel of each row must be byte-aligned. The fill pattern data is transmitted a row at a time.
• the Pattern Pixel Data CRC field (2 bytes) contains a CRC of only the Pattern Pixel Data. If this CRC fails to check then the Pattern Pixel Data can still be used but the CRC error count is incremented.
• the Parameter CRC field (2 bytes) contain a 16-bit CRC of all bytes from the Packet Length to the Packet Type. If this CRC fails to check then the entire packet is discarded.
• the Communication Link Data field contains the raw data from the communication channel. This data is simply passed on to the computing device in the display.
• the Communication Link Data CRC field (2 bytes) contains a 16-bit CRC of only the Communication Link Data. If this CRC fails to check then the Communication Link Data is still used or useful, but the CRC error count is incremented.
• the Interface Type field (1 byte) specifies the new interface type to use.
• the value in this field specifies the interface type in the following manner. If the value in Bit 7 is equal to '0' the Type handoff request is for the forward link, if it is equal to T, then the Type handoff request is for the reverse link. Bits 6 through 3 are reserved for future use, and are generally set to zero. Bits 2 through 0 are used to define the interface Type to be used, with a value of 1 meaning a handoff to Type-I mode, value of 2 a handoff to Type-U mode, a value of 3 a handoff to Type-HI mode, and a value of 4 a handoff to Type-IV mode. The values of '0' and 5 through 7 are reserved for future designation of alternative modes or combinations of modes.
• the Interface Type field (1 byte) has a value that confirms the new interface type to use. The value in this field specifies the interface type in the following manner. If Bit 7 is equal to '0' the Type handoff request is for the forward link, alternatively, if it is equal to 1' the Type handoff request is for the reverse link. Bit positions 6 through 3 are currently reserved for use in designating other handoff types, as desired, and are generally set to zero.
• bit positions 2 through 0 are used define the interface Type to be used with a value of '0' indicating a negative acknowledge, or that the requested handoff cannot be performed, values of T, '2', '3', and '4' indicating handoff to Type-I, Type-II, Type-in, and Type-IV modes, respectively. Values of 5 through 7 are reserved for use with alternative designations of modes, as desired.
• the 1-byte Interface Type field indicates the new interface type to use.
• the value present in this field specifies the interface type by first using the value of Bit 7 to determine whether or not the Type handoff is for the forward or reverse links.
• a value of '0' indicates the Type handoff request is for the forward link, and a value of T the reverse link.
• Bits 6 through 3 are reserved for future use, and as such are generally set to a value of zero.
• Bits 2 through 0 . are used to define the interface Type to be used, with the values 1, 2, 3, and 4 specifying the use of handoff to Type-I, Type-II, Type-HI, and Type-IV modes, respectively.
• the use of values 0 and 5 through 7 for these bits is reserved for future use.
• the Audio Channel Enable Mask field (1 byte) contains a group of flags that indicate which audio channels are to be enabled in a client. A bit set to one enables the corresponding channel, and a bit set to zero disables the corresponding channel Bits 0 through 5 designate channels 0 through 5 which address left front, right front, left rear, right rear, front center, and sub-woofer channels, respectively. Bits 6 and 7 are reserved for future use, and in the mean time are generally set equal to zero.
• the Audio Sample Rate field(l byte) specifies the digital audio sample rate.
• the values for this field are assigned to the different rates with values of 0, 1, 2, 3, 4, 5, 6, 7, and 8 being used to designate 8,000, 16,000, 24,000, 32,000, 40,000, 48,000, 11,025, 22,050, and 44,100 samples per second (SPS), respectively, with values of 9 through 254 being reserved for use with alternative rates, as desired, so they are currently set to '0'.
• a value of 255 is used to disable the reverse-link audio stream.
• the Sample Format field (1 byte) specifies the format of the digital audio samples.
• Bits[l:0] are equal to '0', the digital audio samples are in linear format, when they are equal to 1, the digital audio samples are in ⁇ -Law format, and when they are equal to 2, the digital audio samples are in A-Law format.
• Bits[7:2] are reserved for alternate use in designating audio formats, as desired, and are generally set equal to zero.
• the Content Protection Type field (1 byte) specifies the digital content protection method that is used. A value of '0' indicates Digital Transmission Content Protection (DTCP) while a value of 1 indicates High-bandwidth Digital Content Protection System (HDCP). The value range of 2 through 255 is not currently specified but is reserved for use with alternative protection schemes as desired.
• the Content Protection Overhead Messages field is a variable length field containing content protection messages sent between the host and client.
• the Transparent Color Enable field (1 byte) specifies when transparent color mode is enabled or disabled. If Bit 0 is equal to 0 then transparent color mode is disabled, if it is equal to 1 then transparent color mode is enabled and the transparent color is specified by the following two parameters. Bits 1 through 7 of this byte are reserved for future use and are typically set equal to zero.
• the Video Data Format Descriptor field (2 bytes) specifies the format of the Pixel Area Fill Value.
• FIG. 11 illustrates how the Video Data Format Descriptor is coded. The format is generally the same as the same field in the Video Stream Packet.
• the Pixel Area Fill Value field uses 4 bytes allocated for the pixel value to be filled into the window specified above.
• the format of this pixel is specified in the Video Data Format Descriptor field.
• the Parameter CRC field (2 bytes) contains a 16-bit CRC of all bytes from the Packet Length to the Packet Type. If this CRC fails to check then the entire packet is discarded.
• the All Zero field (1 byte) contains zeroes to ensure that all MDDIJData signals are in the zero state prior to disabling the line drivers during the first Guard Time period.
• the Guard Time 1 field (8 bytes) is used to allow the MDDIJData line drivers in the host to disable before the line drivers in the client (display) are enabled.
• the host disables its MDDIJData line drivers during bit 0 of Guard Time 1 and the Display enables its line drivers immediately after the last bit of Guard Time 1.
• the Measurement Period field is a 512 byte window used to allow the Display to respond with a Oxff, Oxff, 0x0 at half the data rate used on the forward link. This rate corresponds to a Reverse Link Rate Divisor of 1.
• the Display returns this response immediately at the beginning of the Measurement Period. This response will be received at a host at precisely the round trip delay of the link after the beginning of the first bit of the Measurement Period at the host.
• the MDDI JData line drivers in the Display are disabled immediately before and immediately after the Oxff, Oxff, 0x00 response from the Display.
• Guard Time 2 8 bytes
• Client MDDIJData line drivers to disable before line drivers in the Host are enabled.
• Guard Time 2 is always present but is only required when the round trip delay is at the maximum amount that can be measured in the Measurement Period.
• the Client disables its line drivers during bit 0 of Guard Time 2 and the Host enables its line drivers immediately after the last bit of Guard Time 2.
• the Driver Re-enable field (1 byte) is set equal to zero, to ensure that all MDDIJData signals are re-enabled prior to the Packet Length Field of the next packet.
• the Parameter CRC field (2 bytes) contains a 16-bit CRC of all bytes from the Packet Length to the Packet Type. If this CRC fails to check then the entire packet is discarded.
• the Calibration Data Sequence field contains a 512 byte data sequence that causes the MDDIJData signals to toggle at every data period.
• the MDDI host controller sets all MDDIJData signals equal to the strobe signal.
• the display clock recovery circuit should use only MDDI_Stb rather than MDDI Stb Xor MDDIJDataO to recover the data clock while the Calibration Data Sequence field is being received by the client Display.
• the Calibration Data Sequence will generally be one of the following based on the interface Type being used when this packet is sent:
• Type I Oxaa, Oxaa ... or 0x55, 0x55...
• Type TV Oxff, 0x00, Oxff, 0x00 ... or 0x00, Oxff, 0x00, Oxff ...
• FIGS. 62 A and 62B An example of the possible MDDIJData and MDDI_Stb waveforms for both the Type-I and Type-U Interfaces are shown in FIGS. 62 A and 62B, respectively.

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Multimedia (AREA)
• Computer Hardware Design (AREA)
• General Physics & Mathematics (AREA)
• Physics & Mathematics (AREA)
• Computer Security & Cryptography (AREA)
• Human Computer Interaction (AREA)
• Business, Economics & Management (AREA)
• General Business, Economics & Management (AREA)
• Communication Control (AREA)
• Mobile Radio Communication Systems (AREA)
• Information Transfer Systems (AREA)
• Synchronisation In Digital Transmission Systems (AREA)
• Data Exchanges In Wide-Area Networks (AREA)
• Dc Digital Transmission (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
• Controls And Circuits For Display Device (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (2)

Family

ID=34193262

Family Applications (1)

Country Status (11)

Cited By (17)

Families Citing this family (107)