KR100814223B1 - Integrated addressing scheme for use in a system having a tree structure - Google Patents

Abstract

The system includes at least one transmitter, at least one repeater (including a router) and optionally at least one receiver, and generally has a tree structure. Commands (each with one address attached) and data may be sent downstream from each transmitter to each repeater coupled to the transmitter and from each repeater to each device coupled to the repeater. Preferably, each router is assigned a router access address (shared with other routers) and a unique router address. In response to the router access address and management command, the router executes a management function. Preferably, each repeater has at least one other common address (e.g., content protection address), and the system implements one protocol, in which the command starts at the root device and moves only downstream. The response only moves upstream, and the commands broadcast by the root device are observed by each repeater, and the response is point-to-point, only by the device in the diameter path between the response-sending device and the root device. Other aspects of the invention are transmitters, repeaters and receivers, and methods of operating them.

Repeater, Router, Tree Structure, Router Access Address, Router Address

Description

INTEGRATED ADDRESSING SCHEME FOR USE IN A SYSTEM HAVING A TREE STRUCTURE}

In a preferred embodiment, the present invention relates to a system having a tree structure and configured to distribute data (e.g. video data) to multiple devices, each repeater in the system having a unique router address.

There are several well known serial links for transmitting video data and other data. One conventional serial link is known as a transition minimized differential signaling interface (“TMDS” link). This link is mainly used for the high speed transfer of video data from the set top box to the television and also for the high speed transfer of video data from the host processor (e.g., personal computer) to the monitor. Among the characteristics of TMDS links are the following characteristics:

1. Video data is encoded and then transmitted as an encoded word (each 8-bit word of digital video data is converted to an encoded 10-bit word before being transmitted);

2. The encoded video data and the video clock signal are transmitted as differential signals (the video clock and the encoded video data are transmitted as differential signals over a pair of conductors without the presence of a ground line);

3. Three conductor pairs are used to transmit the encoded video, and a fourth conductor pair is used to transmit the video clock signal;

4. Signal transmission takes place in one direction from a transmitter (typically associated with a desktop or portable computer, or other host) to a receiver (typically an element of a monitor or other display device).

It is proposed to transmit encrypted video data over a TMDS serial link (eg from a set top box to a television).

Other serial links that are proposed to transmit encrypted video and audio data include the proposed "High Definition Multimedia Interface" developed by Silicon Image, Matsushita Electric, Royal Philips Electronics, Sony, Thomson Multimedia, Toshiba and Hitachi. ) "Interface (" HDMI "link).

In addition, to encrypt digital video data to be transmitted through a "digital video interface" ("DVI" link) adopted by the Digital Display Working Group, and to decrypt the encrypted video data in a DVI receiver, It is proposed to use a cryptographic protocol known as the "High-bandwidth Digital Content Protection" ("HDCP") protocol. The DVI link can be implemented to include two TMDS links (shared a common pair of conductors carrying video clock signals) or one TMDS, as well as additional control lines between the transmitter and the receiver. We will describe the DVI link (including one TMDS link) with reference to FIG. 1. The DVI link of FIG. 1 comprises a transmitter 1, a receiver 3, and the following conductors between the transmitter and the receiver: four conductor pairs (channel 0, channel 1 and channel 2 for video data, and Channel C) for the video clock signal; Bidirectional communication between the monitor and the transmitter associated with the receiver, in accordance with the conventional display data channel standard ("Display Data Channel Standard" of the Video Electronics Standards Association (VESA), Version 2, Rev. 0, dated April 9, 1996). Display data channel ("DDC") lines for; A hot plug detection (HPD) line (where the monitor sends a signal that allows the processor associated with the transmitter to identify the presence of the monitor); An analog line (transmitting analog video to the receiver); And a power line (providing DC power to the receiver and a monitor associated with the receiver). The display data channel standard monitors associated with the receiver, including transmission by the monitor of Extended Display Identification ("EDID") data that specifies various characteristics of the monitor, and transmission by the transmitter of control signals for the monitor. Specifies a protocol for bidirectional communication between the transmitter and the transmitter. The transmitter 1 comprises three identical encoder / serial converter units (units 2, 4 and 5) and additional circuits (not shown). The receiver 3 comprises three identical recovery / decoder units (units 8, 10 and 12) and interchannel alignment circuits 14, and additional circuits (not shown) connected as shown.

As shown in FIG. 1, circuit 2 encodes data to be transmitted over channel 0, and serializes the encoded bits. Similarly, circuit 4 encodes the data to be transmitted over channel 1 (serializes the encoded bits), and circuit 6 encodes the data to be transmitted over channel 2 (and serializes the encoded bits). To convert). Each of the circuits 2, 4, and 6 is controlled by selectively encoding a digital video word (in response to a DE with a high value) or a control or sync signal pair (in response to a DE with a low value). Responsive to a signal (an active high binary control signal called a " data enable " or " DE " signal). Each of the encoders 2, 4, and 6 receives a different pair of control or synchronization signals: the encoder 2 receives horizontal and vertical synchronization signals HSYNC and VSYNC; The encoder 4 receives the control bits CTL0 and CTL1; Encoder 6 receives control bits CTL2 and CTL3. Therefore, each of the encoders 2, 4 and 6 generates an in-band word representing the video data (in response to the DE having a high value), where the encoder 2 is HSYNC (in response to the DE having a low value). And generate an out-of-band word representing the value of VSYNC, encoder 4 generates an out-of-band word representing the values of CTL0 and CTL1 (in response to DE having a low value), and encoder 6 (low value) Generate an out-of-band word representing the values of CTL2 and CTL3). In response to the DE having a low value, each of the encoders 4 and 6 is one of four specific out-of-band words representing the values 00, 01, 10 or 11, respectively, of the control bits CTL0 and CTL1 (or CTL2 and CTL3). Create one.

Other serial links include a set of serial links known as Low Voltage Differential Signaling ("LVDS") links (eg, "LDI", or LVDS Display Interface), each of which is TIA / EIA. Meets the -644 standard or IEEE-1596.3 standard, Ethernet link, Fiber Channel link, Serial ATA link used by disk drives, and others.

The present invention is applicable to a system comprising a device (e.g., a transmitter, a receiver and a repeater) connected by a serial link, and also a device (e.g., a transmitter, a receiver and a repeater) connected by a parallel link. Applicable to the containing system.

The term "channel" as used herein refers to a portion of a link used to transmit data (e.g., a particular conductor or pair of conductors to which data is transmitted between a transmitter and a receiver, and for transmission and / or recovery of data). Special circuitry within the transmitter and / or receiver used), and the technique used to transmit data over the link.

In a multi-drop distribution system (eg, a multi-branch video distribution system), there is one source (transmitter) and one or more receivers (eg, receivers associated with the video display device). All these devices require a unique address. The systems may also include one or more relays that may need their own address. However, it would be desirable for such a system to be able to broadcast several commands from the source to all receivers and repeaters.

In some conventional video distribution systems (e.g., systems whose source transmits video over a video channel of a DVI link), each receiver is connected to a DDC bus (e.g., a DDC line of a DVI link as described above). It is associated with a display device comprising an EDID PROM accessed over. The DDC bus is very similar to the I2C bus. Each EDID PROM in such a system has the same fixed address. Therefore, if the system has a tree structure, it is impossible to reliably read individual EDID PROMs, or it is impossible to know which reception is associated with the display device from which the EDID data has been read.

There is a problem associated with the DDC bus not being designed for large distributed systems. This has an electrical limitation that limits the range, increasing the difficulty of extending or buffering the range.

In some systems having a tree structure (defined later), each receiver includes an HDCP (or other) content protection subsystem (“block”). Each such block must be addressed individually. HDCP does not solve this problem in any (mainly undefined) way of moving data between branches unless it is by the assumption that each branch will be a separate entity.

The present invention seeks to solve these problems and limitations of the prior art in an integrated manner.

In one kind of embodiment, the invention is a communication system comprising at least one transmitter and at least one repeater (and also typically at least one receiver), each transmitter, repeater and receiver being connected to at least one by a link. It is connected to other transmitters, repeaters and receivers. Data (e.g. video data or audio data) and commands (each with an address attached) are down from each transmitter to each receiver connected and from each repeater to each device (relay or receiver) connected. Stream can be sent. Typically, the system has a tree structure, and the transmitter is a root node (sometimes called a "root device").

Preferably, each repeater includes a router to which a unique address (called a "router address") is assigned at the time of repeater manufacture. The router address may be an identification or a serial number, and optionally also used for at least one purpose other than identifying the router. The router address may consist of several parts, including some parts that are common to a particular vendor or device family. For example, the router address may include a vendor ID field, a product ID field and also optionally a device type field, and a sub-code. Only the sub-code needs to be changed from one specific router to the next. Alternatively, a router does not have a unique address (in that the router or the repeater containing the router does not remember the unique address) but is located at a unique location within the system and therefore simply "addressed" by this unique location. Can be. For example, if the system has a tree structure with only one repeater input port per branch, an upstream device (e.g., a transmitter) may attach a command (common address only) to one repeater over a particular link, or Attached without an address, the expression "common address" is not unique for one device in the system, but instead can assert an address shared with at least one other device in the system) The router of is the only router that receives a command and responds to that command.

Preferably, each relay is also assigned a common address (called a "router access" address) to access its router. The router access address is distinct from the router address described above. In response to the correct router access address and attached management function command, the router of the repeater performs the management function. Examples of management functions are the use of routers as identification, status checking and control functions, and conduits to other devices further downstream. Exemplary functions of the latter type include reading data from the downstream repeater (and sending such data to the upstream device that requested the data), and at least one of data, address, and commands from the upstream device to one or more downstream repeaters. Will be sent to. Typically, a repeater that receives a router access address (from an upstream device over a link) is the only relay connected directly to the upstream device over the link. In this case, no collision may occur despite the fact that the router access address is shared by two or more repeaters in the system.

Preferably, each repeater has at least one other common address, and each receiver has at least one common address. Examples of such common addresses include memory (in or associated with a repeater or receiver) containing identification data (e.g., a PROM containing Extended Display Identification (EDID) data or similar identification data, in a monitor associated with the repeater). An "identification data" address for access, and a "content protection" address for accessing the selected content protection subsystem (eg, crypto engine) of the device.

A preferred embodiment of the system includes a repeater configured to execute a certain type of command (eg, to read or otherwise process data received with such a command) only if the command is appended with a unique router address for the repeater. do. For example, one embodiment of a repeater receives a message, a command to send this message to a downstream device (e.g., a downstream repeater), and a router access address (shared by the repeater with at least one other repeater). However, when not receiving the router's router address, the relay responds by executing the command without opening, reading or otherwise processing the message. When this repeater also receives its router address along with a command, message and router access address, the repeater reads the message (in response to this and performs some internal operation, where the "internal operation" is located inside the repeater). One action), and also executes the command by sending a message downstream. In another example, when an embodiment of a repeater receives a command to perform an identification, status check or control operation, the router of the repeater executes the operation specified by the command only if the command is appended with a router address.

Repeaters of the present system typically require that a command (or command and data) execute a type of command (and / or such a command) even if no unique address (e.g., the unique address of the router of the repeater) is appended. To process the data received together). For example, when a repeater receives a "broadcast" command, a message, and a router access address (shared by at least one other repeater with this repeater) but no unique router address, the repeater executes the command. It is also possible to respond (eg by sending commands and messages to each downstream repeater connected) and by reading the message and executing internal operations in response to the message. In a variation of this example, only the message is appended to the broadcast command (no address is appended), and the repeater executes the command (e.g., sends the command and message to each connected downstream repeater), It also responds to commands and messages by reading the message and performing internal operations in response to the message.

In one kind of embodiment, the system has a tree structure and is configured to determine addresses and commands in accordance with the present invention, and at least one relay and at least one to which at least one such address is assigned. Other devices. Preferably, each repeater has a router that performs at least three functions: the ability to gather information about the repeater itself (such as address, capability and status); Switching of routers, which can also be used to isolate the branch of a system that responds or makes noise when not responding properly or when it is not responding properly Well done using function); And broadcasting the commands and / or messages of the routers of the repeaters connected downstream of the repeaters and sending the appropriate responses back upstream.

Preferably, the system implements a new transmission protocol. According to the new transport protocol, commands start at the root device and only move outwards (downstream). The response only moves inward (upstream) towards the root device. The command can be broadcast by the root device, and the command being broadcast is observed by each repeater in the system. The response is point-to-point and is only observed by the device in the diameter path between the response-originating device and the root device. However, commands and responses may not need to share the same communication path. If they do not share the same path, then each channel they share along the path will typically not support communication in both directions at the same time, so the router only sends commands (attached to addresses) downstream over the channel during the first phase. In the sense that each router receives a response (and sends a response upstream) from the downstream device during the next step, each router will need to switch directions between each step of the transaction. Alternatively, the command and response to it would use a completely different path. For example, in one embodiment, the repeater commands commands downstream on one or more video (or video clock) channels of the TMDS link (eg, in a packet between video frames, or on a modulated clock channel). Send, and the receiver receives a response on the DDC bus.

The command (with address) is used to determine the router (using its own preset unique address), the address to which the router should send the command, the command code (eg, write code or read code), and any other suitable data. Can be. The response will typically include result data (if appropriate), and an acknowledgment (completion) code.

Preferred embodiments of the present invention support "split" transactions in the following senses. In the first part of the split transaction, the root device (which may be a repeater if the repeater is the root device of a branch of a larger system) sends an address, command and any associated data to the connected repeater, and the operation has started but not yet. Receive an acknowledgment (eg, a "retry" acknowledgment) indicating that it has not been completed. In the second part of the split transaction, the root device receives an "error" acknowledgment (indicating that the operation is not supported or could not be completed for some other reason) or a completion acknowledgment. In response to receiving the retry acknowledgment, the root device begins another transaction with the same device. This transaction completes or receives a retry response as well.

In a preferred embodiment of the present system, the tree management task is executed by the relay (rather than by the root device) as follows:

Each repeater is responsible for collecting data that characterizes the structure of each branch of the device tree downstream. In this way, the entire tree can be determined in a hierarchical manner, and the root device (and each relay) need only look up devices that are immediately downstream from there (using the appropriate known router address and / or router access address). have;

Each repeater contains one router, which is used as a router for itself and as a router for each branch (downstream of the repeater) that does not contain its own router or routers. This provides backward compatibility and can reduce the cost of implementing a pure "leaf" node (the "leaf" node has no devices connected downstream therefrom). If the tree structure indicates that a particular leaf node does not have a router, a router directly upstream from the leaf node (called "substitute" router) may assume router responsibility for that leaf node. Commands for reading the EDID PROM or HDCP registers within (or associated with) the node may be directed to a surrogate router, which then decodes the command and translates the command as necessary to include the branch containing the leaf node. You can run the necessary functions on the The surrogate router preferably does this separately from other branches and using a predetermined function address;

Each repeater monitors routers connected downstream from the repeater to find "babbling" or other incorrect behavior, and isolates any downstream routers that are not operating properly. The repeater knows the structure of the downstream tree and is able to find and decrypt (e.g., typically find and decrypt each "broadcast" command received from the upstream device) at least some commands it receives from the upstream device. You can do this because you can. In some cases, relays are configured to send commands only to their downstream routers that are expected to respond to commands, but relays send commands to all downstream routers (including those that are not expected to respond to commands). Even when configured to, the repeater is preferably configured to actively disconnect any malfunctioning downstream router;

Each repeater can monitor the status of downstream branches and send "interrupt" (or state change) information upstream to the root device.

In some embodiments of the invention, the commands, addresses and data are transmitted downstream over two or more different channels of the link. In some embodiments, the response to the command is sent upstream on a different channel (or different channels) on a link different from the channel (s) on which the command is sent downstream.

Another aspect of the invention is a transmitter, repeater and receiver for use in any embodiment of the present system, and a method of operating any embodiment of the transmitter, repeater or system of the present invention.

In some embodiments, the repeater of the present invention is a router configured to transmit (but do not translate or otherwise change) commands, addresses and / or data to downstream devices, and also typically to perform identification, status checking and control functions. to be. In other embodiments, the repeater of the present invention may send translated versions of commands, addresses and / or data to downstream devices, and the router's router typically also performs identification, status checking and control functions, and And / or without any other changes) may send the command, address and / or data to the downstream device. For example, in one of the later embodiments, the repeater translates the received data in a predetermined manner (e.g., by decrypting the data, translating the decrypted data, and re-encrypting the translated data). ), The translated data can be sent downstream.

1 is a block diagram of a conventional system including a digital video interface (DVI) link.

2 is a block diagram of a system that may be implemented in accordance with the present invention.

The term "transmitter" is used herein in a broad sense to refer to any unit capable of transmitting data (and optionally encoding and / or encrypting data to be transmitted) over a communication link. The term "receiver" is used herein in the broad sense to refer to any unit capable of receiving (and optionally, decoding and / or decrypting received data) transmitted over a communication link. . Unless otherwise specified, the link can be a TMDS link or some other serial link, but it is not necessary. For example, the term transmitter can refer to a transceiver that performs not only the function of the transmitter but also the function of the receiver.

Other expressions used herein include:

Downstream : A device (eg, an indication) that is the final destination of transmitted data.

   Toward the device).

Upstream : towards the source of one stream (or other amount) of transmitted data

   Facing.

Repeater : Receives content (e.g., encrypted digital data)

   Send tents, or receive content and translate it (e.g.,

   Such as decrypting and / or otherwise altering or translating the content.

   Device configured to transfer tents. One type of repeater (here sometimes

   Referred to as a "switch") receives the data, and in some way

   Send without decrypting or translating. The switch allows for longer links

   Buffer the transmitted data for at least two upstream devices and

   Connected between at least two downstream devices, to any upstream device

   To all downstream devices or any selected one (or subset)

   May be configured to selectively transmit data to the downstream device.

   All downstream links connected to the selected upstream link must have the same resolution and

   Will have timing characteristics).

Router : At least one (and typically more than one) router function

   A subsystem of relays configured to run. Here, the "router function"

   Upstream device (for example, among a number of upstream devices connected to a repeater

   Transmission of content from one) to the downstream device, one from the upstream device

   More downstream devices (e.g., multiple downstream connected to repeaters

   Transfer, or update, the translated version of the content to a selected one of the devices)

   The response of the downstream device to the content from the rim device (or such response).

   A translated version of the answer) to the upstream device. Router is another

   Typically, but not limited to, identification, status check, or control functions

   Configured to execute at least one other management function, such as:

Typically, the present invention is implemented in a system having a tree structure. The expression that the system has a "tree" structure is used herein (including claims) to indicate: that is, the system comprises a transmitter, at least one repeater and also optionally at least one receiver; Each repeater and receiver is connected to the transmitter by a link or to at least one other repeater or receiver; Each transmitter, repeater and receiver is a different node of the system; The transmitter is the root node; The nodes of the system comprise a root node and at least two additional orders of additional nodes to the root node. For example, the system of FIG. 2 has a tree structure and includes a transmitter 1, repeaters 3 and 5 (downstream of the transmitter) connected to the transmitter 1, receivers 7 and 9 connected to the repeater 3; (Downstream of the repeater), and the receiver 11 (downstream of the repeater) connected to the repeater 5. In the system of FIG. 2, the transmitter 1 is the root node, the repeaters 3 and 5 are the primary nodes, and the receivers 7, 9 and 11 are secondary nodes.

In one kind of embodiment, the invention is a communication system comprising at least one transmitter and at least one repeater (and also typically at least one receiver), each relay and receiver being connected by at least one transmitter and And / or to at least one other repeater and / or receiver. Data (e.g., video data or audio data) may be transmitted over each link to at least one repeater at each transmitter and at each repeater to each device (relay or receiver) connected downstream from such repeater. Can be.

Each repeater includes a router. Preferably, the router is provided with a unique address (called a "router address") when the relay is manufactured. The router address may be an identification number (ID) or a serial number, and optionally used for at least one purpose other than identifying the router. For example, the router address can be used in any encryption scheme (eg, can be used as a key selection vector as in the conventional HDCP protocol).

The unique router address can consist of several parts, including some parts that are common to a particular vendor or device family. For example, the router address may include a vendor ID field, a product ID field and also optionally a device type field, and a sub-code. Only the sub-code needs to be changed from one specific router to the next. Preferably, the sub-code is held in some kind of programmable memory (such as EEPROM or FLASH, or laser-trimmed area) of the repeater. The remainder of the router address will not be noticeably changed from relay to relay, so it can be kept in ROM within each relay.

Each repeater also has a common address (to be referred to as a "router access" address) for accessing its router, where the expression "common address" is used herein (including claims), as a device (of a system). Is not unique to, but instead is used to indicate an address shared with at least one other device in the system. The router access address is distinct from the unique "router" address described above. In response to the correct router access address (to which management function commands are attached), the router's router may be identified (such as using the router as an identification, status check, or control function, or the use of the router as a route to another relay further downstream. Not limited) Execute management function. Exemplary functions of the latter type are the reading of data from the downstream repeater (and the transmission of such data to the upstream device that requested the data) and the transfer of data from the upstream device to the downstream repeater. Typically, when a repeater receiving a router access address (from an upstream device over a link) is the only relay connected directly to the upstream device over a link, the router access address is a common address used by two or more repeaters in the system. Despite the fact, no collisions can occur.

In some embodiments of the present system, there is no router with a unique address (in that a router or any repeater containing a router does not remember the unique address). Instead, each router is located in a unique location within the system, so it can simply be "addressed" by this unique location. For example, if the system has a tree structure with only one repeater input port per branch (as in the system of FIG. 2), the upstream device (e.g., transmitter 1 of FIG. 2) is one over a particular link. Since it is possible to assert a command (with only a common address or no address attached) to a relay, the router of this relay is the only router that receives the command and responds to the command.

Preferably each repeater has at least one other common address and each receiver has at least one common address. Typically, each receiver has more than one common address. Examples of such common addresses are "identification data" addresses for accessing memory in a device containing identification data (e.g., a PROM containing the above described Extended Display Identification (EDID) data or similar identification data), and the device. Is a "content protection" address for accessing a selected content protection subsystem (e.g., an HDCP crypto engine, or any other device configured to perform HDCP or non-HDCP content protection functions).

In some embodiments, the repeater of the present system is configured to execute a certain type of command (e.g., read data received with such a command only if the command (or commands and data) is appended with the repeater's unique router address, or To process differently). For example, one such relay may send a message, a command to send the message to a downstream device (eg, a downstream relay), and a router access address (shared by the relay with at least one other relay). When receiving but not receiving its own router address, the repeater responds by executing the command without opening, reading, or otherwise processing the message. In a variation of this example, if the repeater also receives its router address along with the command, message, and router access address, the repeater can read the message (and may perform some internal operation in response to it) and also the message You can execute the command by sending it downstream.

The repeater of the present system may be configured to execute (and / or be accompanied with such a command) a certain type of command even if the command (or command and data) is not appended with a unique address (eg, the router's unique address). To process the data). For example, when a repeater receives "broadcast" commands, messages, and router access addresses (shared with at least one other repeater) but does not receive its own router address, the repeater (each connected down) By sending a command and a message to the stream repeater), and also by reading the message and executing an internal operation in response to the message. In a variation of this example, the broadcast command is appended only by the message (no address is attached), and the repeater executes the command (e.g., by sending a command and message to each connected downstream repeater) and It also reads messages and responds to commands and messages by performing internal operations in response to the messages.

In some embodiments, the broadcast command has an address field that is ignored by each device that receives and executes the broadcast command. Alternatively, the broadcast command has an address field whose content is used (by at least one device that receives and executes the broadcast command) for some purpose that is completely different from the address. The broadcast may include a message (or other data) to be sent with the command, or the message may be attached.

In general, commands received and executed by at least one device of the system may have more than two related addresses (eg, one unique address and one common address), more typically such one The command has only one address associated with it. Each common address is shared by a subset of the devices of the system (eg, where the device implements a bit mask scheme), the subset comprising at least two devices.

The communication system of Figure 2 may be implemented in accordance with the present invention. The system of FIG. 2 has a tree structure and includes a transmitter 1 (root node), a repeater 3 connected to the transmitter 1 by a link 20, and a repeater connected to the transmitter 1 by a link 21. (5), a receiver 7 connected to the repeater 3 by a link 22, a receiver 9 connected to a repeater 3 by a link 23, and a repeater 5 by a link 24; And a connected receiver 11. Repeaters 3 and 5 are primary nodes and receivers 7, 9 and 11 are secondary nodes. The repeater 3 comprises a router 4. The repeater 5 comprises a router 6. The display device 8 is connected to receive video data from the receiver 7, the display device 10 is connected to receive video data from the receiver 9, and the display device 12 is connected to the video from the receiver 11. Is connected to receive data.

Preferably, the transmitter 1 and the receivers 7, 9 and 11 implement content protection (and because each includes a crypto engine), so that the transmitter 1 encrypts the data encrypted via the links 20 and 21. And relays 3 and 5 may send encrypted data to one or more of the links 22, 23 and 24, with each receiver 7, 9 and 11 having a repeater 3 or 5; Can decrypt the encrypted data received. Preferably, each display device 8, 10 and 12 comprises an EDID PROM, which EDID PROM of the device 8 is to be accessed by the transmitter 1 (via the repeater 3 and the receiver 7). The EDID PROM of the device 10 may be accessed by the transmitter 1 (via the repeater 3 and the receiver 9), and the EDID PROM of the device 12 may be connected to the repeater 5 and the receiver ( 11 may be accessed by the transmitter 1.

Typically, the receivers 7, 9 and 11 share the same identification data address. In doing so, each receiver is configured to respond to the identification data address (with the appropriate command attached) by accessing the EDID PROM of the connected display device.

Typically, the receivers 7, 9 and 11 share the same content protection address. In doing so, the content protection subsystem of each receiver executes a content protection operation when an appropriate one of the repeaters 3 and 5 sends these addresses and commands from the content protection subsystem of the transmitter 1 to the receiver. Thereby responding to the content protection address (to which the appropriate command is attached).

According to the invention, each router 4 and 6 has a unique router address, and the repeaters 3 and 5 also share a router access address. These addresses can be used as described above. For example, the transmitter 1 can send the relay 5 a message (via link 21), a command to send this message to a downstream device, and a router access address (but repeater 5). Does not send a unique router address). In this example, router 6 of repeater 5 may respond to these three items by executing a command (by sending a message to receiver 11) without opening, reading, or otherwise processing the message. It is composed. In a variation of the previous example, the transmitter 1 sends (to the relay 5) the unique router address of the repeater 5 with the same commands, messages and router access addresses that the transmitter 1 sent in the previous example. . In this variant, the router 6 of the repeater 5 not only executes the command (sends the message to the receiver 11) but also reads the message (and in response performs certain internal operations). Respond to the two items.

In another example, the repeater 3 may receive a command for transmitting encrypted data (from the transmitter 1) and a router access address to a particular one of the receivers 7 and 9 determined by the command. . In response to the command and router access address, the repeater 3 sends data to the appropriate one of the receivers 7 and 9.

In some implementations of FIG. 2, repeaters 3 and 5 implement content protection functions, each of which is (eg, translation subsystem 25 of repeater 3 or translation subsystem 26 of repeater 5). It includes a crypto engine) within). In some such implementations, the relay 3 may perform content protection operations (e.g., encrypt or decrypt data received from the transmitter 1 in the translation subsystem 25, and convert the encrypted or decrypted data into a router ( 4), and by selectively transmitting an encrypted or decrypted version of the data received from the transmitter 1 to one or both of the receivers 7 and 9 (from the router 4), the appropriate command is Responds to the content protection address). The command may specify which of the receivers 7 and 9 should receive the encrypted or decrypted data.

Repeaters that do not have an EDID PROM and do not implement content protection (eg, a switch-in repeater as defined above) may not require an identification data address or a content protection address, and may not require an EDID or content protection address. May not be configured to respond to. For example, a variation of the repeater 3 in FIG. 1, which consists of only the router 4 without the subsystem 25 (no EDID PROM), is a repeater that is a switch. However, the identification data address and the content protection address may also be assigned to a relay that is simply a switch (these addresses may be shared with at least one other device by such a relay). For example, a variation of the repeater 3 or 5 of FIG. 2 consisting of only a router (e.g., routers 4 or 6) is such that the repeater does not implement content protection (or does not include a cryptographic engine). ) Even if it does not include an EDID PROM, an identification data address and a content protection address may be assigned, in which case this variant of repeater 3 or 5 implements a content protection function and / or comprises an EDID PROM. If replaced by a device, the transmitter 1 may be able to communicate with the replacement device using a predetermined identification data address and / or content protection address.

In some embodiments of the invention, the repeater includes a cryptographic engine, a register that stores a value used by the cryptographic engine to implement the content protection function, and a router. In some cases, the router shares at least some of those registers with the crypto engine.

In an embodiment of the invention where a repeater implements a content protection function and receives a content protection address (from an upstream device) via a link, the receiver is typically the only relay that is directly connected to the upstream device via a link (ie, the link). Is typically a point-to-point link). Therefore, in a typical case, no collision may occur despite the fact that the content protection address is a common address used by two or more repeaters in the system. In response to the content protection command appended with the content protection address, the repeater may execute the command.

The address may be assigned to an apparatus of the system according to the present invention even if the system does not include a repeater and has no tree structure. For example, one such system consists of a transmitter (configured to assert addresses and commands in accordance with the present invention) and at least one other device (assigned at least one such address). In a system where an address has been assigned in accordance with the present invention but does not have a tree structure, the communication between the transmitter and each downstream device preferably occurs as if only a conventional address was assigned to each downstream device. This provides backward compatibility. For example, the transmitter is preferably configured to access the EDID PROM and / or content protection circuitry within (or associated with) that downstream device using a conventional address and a conventional predetermined interface.

In one kind of embodiment, the system has a tree structure and is configured to determine addresses and commands in accordance with the present invention, and at least one relay and at least one to which at least one such address is assigned. Other devices. Preferably, each repeater has a router that performs at least three functions:

The ability to gather information about the repeater itself (such as the address, capabilities and status of the repeater);

The ability to gather equal information about any and all repeaters connected downstream of a repeater. This is done well using the router's switching function, which can also be used to isolate a branch of a system that does not respond properly (or responds or makes a noise when it should not); And

The ability to broadcast commands and / or messages to routers of repeaters connected downstream of the repeater and send the appropriate response back upstream.

Preferably, the system implements a new transport protocol. According to the new transport protocol, commands start at the root device and only move outwards (downstream). The response only moves inward (upstream) towards the root device. The command can be broadcast by the root device, and the command being broadcast is observed by each repeater in the system. The response is point-to-point and is only observed by the device in the diameter path between the response-originating device and the root device. This new transport protocol is different from the protocol used on conventional DDC (I2C) lines, but is compatible with that protocol.

According to the new transport protocol, commands and responses can share the same communication path, but need not be. If they do not share the same path, then each channel they share along the path will typically not support communication in both directions at the same time, so the router only sends commands (attached to addresses) downstream over the channel during the first phase. In the sense that each router receives a response (and sends a response upstream) from the downstream device during the next step, each router will need to switch directions between each step of the transaction. Routers can be easily implemented to function in this manner since there will be a single boundary between transaction steps, and this boundary will be distinct and easily identified.

Alternatively, the command and response to it would use a completely different path. For example, in one embodiment, the repeater commands commands downstream on one or more video (or video clock) channels of the TMDS link (eg, in a packet between video frames, or on a modulated clock channel). Send, and the receiver receives a response on the DDC bus.

The command (with an address) includes a router (using its own preset unique address), an address to which the router should send the command, a command code (e.g., a write code or a read code), and any other suitable data. You can decide. The response will typically include result data (if appropriate), and an acknowledgment (completion) code.

There may be some delay associated with a given operation (eg, upon execution of some commands). Waiting for a long-delay operation to complete is typically undesirable. Therefore, the preferred embodiment of the present invention supports a "split" transaction in the following sense. In the first part of the split transaction, the root device sends an address, command and any associated data to the relay and receives an acknowledgment (eg, a "retry" acknowledgment) indicating that the operation has started but not yet completed. do. In the second part of the split transaction, the root device receives an "error" acknowledgment (indicating that the operation is not supported or could not be completed for some other reason) or a completion acknowledgment. In this regard, the root device may be a repeater, ie a repeater which is the root device of a branch of a larger system.

In response to receiving the retry acknowledgment, the root device initiates another transaction to the same device. This transaction completes or receives a retry response as well.

In the preferred embodiment, the tree management task is off-loaded to the relay device (from the root device) as follows:

(1) Each repeater is responsible for collecting data that characterizes the structure of each branch of the device tree downstream. In this way, the entire tree can be determined in a hierarchical manner, and the root device (and each relay) need only look up devices that are immediately downstream from there (using the appropriate known router address and / or router access address). have;

(2) Each repeater contains one router, which is used as a router for itself and as a router for each branch (downstream of the repeater) that does not contain its own router or routers. This provides backward compatibility and can reduce the cost of implementing a pure "leaf" node (the "leaf" node has no devices connected downstream therefrom). If the tree structure indicates that a particular leaf node does not have a router, the router that is upstream from the leaf node (called "substitute" router) will assume router responsibility for that leaf node. Commands for reading the EDID PROM or HDCP registers within (or associated with) the node may be directed to a surrogate router, which then decodes the command and translates the command as necessary to include the branch containing the leaf node. You can run the necessary functions on the The surrogate router preferably does this separately from other branches and using a predetermined function address;

(3) Each repeater monitors routers connected downstream from the repeater to find "noise" or other incorrect operation, and isolates any downstream routers that are not operating properly. The relay knows the structure of the downstream tree and finds and decrypts at least some commands it receives from the upstream device (eg, typically finds and decrypts each "broadcast" command received from the upstream device). You can do this because you can. In some cases, relays are configured to send commands only to their downstream routers that are expected to respond to commands, but relays send commands to all downstream routers (including those that are not expected to respond to commands). Even when configured to, the repeater is preferably configured to actively disconnect any malfunctioning downstream router;

(4) Each repeater can monitor the status of downstream branches and send "interrupt" (or state change) information upstream to the root device.

Routers of the type described herein, except that routers are optionally implemented (and not required) within repeaters connected as "leaf" nodes (nodes without devices connected downstream of the repeater), It is well implemented within each repeater of the system implementing the invention. A repeater connected as a leaf node may be a leaf node if the leaf node requires at least one router capability (eg, extended diagnostic or control capability, or additional downstream bandwidth or buffering capability) other than switching capability, or If a content protection mechanism (or other function) within requires a router interface for its own use, it may include a router (implementing a whole or a subset of the router functions).

In a system implementing the present invention, tree management preferably occurs as follows:

(1) the root device detects when a new device is connected to the system;

(2) If the new device is a repeater, the repeater will have a router. The root device queries this router to find information about any and all "trees" (branches of the entire system) that are downstream of the new device. The root device makes this information a cohesive map of the entire system. This "map update" operation may take a considerable time, but the structure of the present system allows many operations to proceed side by side with the map update operation. The map update operation can be accomplished without using the command / response capabilities of the preferred embodiment of the present system, although these capabilities can optionally be used when a repeater is present;

(3) Once the updated map is created, the root device preferably uses that updated map to individually address each device in the system using the command / response capabilities of the preferred embodiment of the present invention. Leaf nodes that do not have routers are well addressed through their "substitute" router (s) as described above;

(4) The root device sometimes queries the nearest router (s) to find state change information (each router collects such state change information well from all downstream routers in succession). When a state change is detected, the root device can query each appropriate individual router to find more detailed information.

The router of the embodiment of the present repeater (eg, router 4 of the repeater 3 of FIG. 2) has at least two inputs (each of which can be connected to an upstream device via a link) and at least two outputs (these Each of which may function as a switch). The switch may be a crosspoint switch that allows any of its inputs to be connected to any of its outputs. In a variation of such an implementation, the router functions as two or more switches "ganged" according to the following rules:

No two input ports can be connected together;

Any output port can be connected to only one input port at a time.

   have;

One input port can be connected to more than one output port;

One output port need not be connected to any input port;

A TMDS link (or other multi-channel link) on one input port

   Whenever connected to a TMDS link (or other multi-channel link) on an outgoing port

   Corresponding communication channels should always be connected together.

In another kind of embodiment, the present invention is directed to a method of designing a tree-structured communication system, the system having a transmitter, a primary router configured to assert addresses and commands, and connected to the transmitter downstream from the transmitter. At least one primary repeater, and at least two secondary repeaters, each of which has a secondary router and is configured to be connected to the primary repeater downstream from the primary repeater. . The method includes assigning a router access address to each of the secondary routers such that all secondary routers share the router access address; And assigning a unique router address for each said primary router and each secondary router such that no two primary and secondary routers share one said router address.

Optionally, the method also includes assigning a router access address to each of the primary routers such that both primary and secondary routers share the router access address, and all secondary routers to each additional address. One or two of allocating at least one additional address to each secondary repeater. The at least one additional address may comprise one or two of an identification data address (for use in triggering an access to memory containing identification data), and a content protection address.

While certain forms of the invention have been shown and described, it should be understood that the invention is defined by the claims, and is not limited to the specific embodiments described and illustrated. For example, although some specific embodiments have been described herein as methods or systems for transmitting video data, variations of these embodiments are contemplated in which audio data (or other data) is transmitted rather than video data.

Claims (83)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A communication system having a tree structure comprising a root node and at least two additional orders of additional nodes for the root node, A transmitter configured to assert a command; At least one primary repeater having a first router and coupled to the transmitter downstream from the transmitter; And At least two secondary repeaters, each having a secondary router and each connected to the primary repeater downstream from the primary repeater; Wherein the transmitter is the root node, each of the primary repeater and the secondary repeater is one of the additional nodes, The first router is configured to broadcast at least one of the commands to the secondary repeater and send a response from the secondary repeater upstream to the transmitter. delete delete delete delete delete delete delete delete delete delete A communication system having a tree structure comprising a root node and at least two additional orders of additional nodes for the root node, A transmitter configured to assert a command; At least two primary repeaters, each having a first router and connected to the transmitter downstream from the transmitter; And At least two secondary repeaters each having a secondary router and each connected to one of the primary repeaters downstream from one of the primary repeaters Wherein the transmitter is a root node, each of the primary repeater and the secondary repeater is one of the additional nodes, The transmitter is configured to broadcast at least one of the commands to the primary repeater, each primary repeater sending one of the commands to each of the secondary repeaters coupled to the primary repeater, Configured to respond to one of the commands by executing at least one internal operation in response to one, wherein each of the primary repeaters sends a response upstream to the transmitter from the secondary repeater coupled to the primary repeater. System configured to send. delete In a repeater for use in a communication system, At least one input configured to be connected to an upstream link; At least one output configured to be coupled to the downstream link; And A router connected to each said input and each said output Wherein the router has a router access address and a unique router address, the router is configured to execute a management function in response to a management function command and the router access address, wherein the router is configured to have the second router address be a second command. And to execute at least one other function in response to the second command only when appended to. 51. The repeater of claim 50 wherein the management function is one of an identification, status check, and control function. delete 51. The repeater of claim 50, wherein said management function is an operation in which said router transmits at least one of data, an address and a command to a device connected to one said output through a downstream link. delete delete delete delete delete delete delete delete delete delete In the repeater for use in a communication system having a tree structure having a root node that is a transmitter and at least two different orders of additional nodes to the root node, At least one input configured to be coupled to the transmitter via an upstream link; At least two outputs, each configured to be connected to a different one of said additional nodes via a different one of a set of downstream links; And A router connected to each said input and each said output Wherein, in response to at least one command, the router broadcasts the command to another repeater connected to the output over the downstream link and sends a response from the other repeater to one of the inputs. Repeater composed. delete delete delete delete delete delete delete A transmitter for use in a communication system, At least two outputs, each configured to be connected to a different link; And Circuitry coupled to each of the outputs and configured to assert management function commands and attached router access addresses to each of the outputs for transmission over each link coupled to one of the outputs. Wherein the circuit is further configured to assert a second command and an attached router address to each of the outputs for transmission on each link coupled to one of the outputs. delete delete delete delete delete A transmitter for use in a communication system having a tree structure having a root node that is a transmitter and at least two different orders of additional nodes for the root node, At least two outputs, each configured to be connected to a different link; And Circuitry coupled to each said output for determining a broadcast command to each said output for transmission on each link coupled to one of said outputs Wherein the broadcast command is a command that causes a router to transmit the broadcast command to each repeater connected to the router, and cause the router to execute at least one internal operation. A transmitter configured to assert an address and command, at least one primary repeater having a primary router configured to connect to the transmitter downstream from the transmitter, and each having a secondary router downstream from the primary repeater A method of designing a tree-structured communication system comprising at least two secondary repeaters configured to be connected to a primary repeater, Assigning a router access address to each of the secondary routers such that all the secondary routers share the router access address; And Assigning a unique router address to each of the primary router and each of the secondary routers such that no two of the primary and secondary routers share one unique router address. How to include. delete delete delete delete

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