FR2969329A1 - SYSTEM FOR CONNECTING CHANNEL AUDIO AND VIDEO EQUIPMENT - Google Patents

Abstract

An electronic equipment includes an output interface having a high rate output channel (AVo), a medium rate auxiliary bidirectional channel (AUXo), and a power relay pin (DP_PWRo); an input interface having a high rate input channel (AVi), a medium rate auxiliary bidirectional channel (AUXi), and a power relay pin (DP_PWRi); and a management circuit (16) adapted to organize the relay of a stream from the input channel to the output channel, and the data relay between the auxiliary channels of the input and output interfaces. It includes a power source (12) configured to activate the power relay pin (DP_PWRi) of the downstream interface, regardless of the power supply of the equipment. The interfaces and the management circuit are also powered from the power relay pin (DP_PWRo) of the upstream interface.

Description

TECHNICAL FIELD OF THE INVENTION The invention relates to the connection of several source equipment for digital audio and / or video signals (DVD player, cable / satellite demodulator, transmission box). video access via internet, computer ...) to rendering equipment (television, monitor, projector, home cinema equipment ...). State of the art To connect source equipment to reproduction equipment, digital links are now available according to HDMI and DisplayPort standards, HDMI connections being more common. These digital links are used to transfer uncompressed high-definition video and one-way audio signals. The 1.4A version of the HDMI standard provides audio return channels and remote control (CEC Standard). VESA DisplayPort 1.1A and 1.2 provide for a bidirectional auxiliary channel. To connect multiple source devices to a playback device using HDMI links, a point-to-point connection is made, ie the playback equipment must have as many HDMI connectors as there are sources to connect. If you want to connect more sources, you have to insert separate switch boxes. The choice of the source to be rendered becomes complex. In the analogue world, there was the "SCART" or "Scart" link, which made it possible to connect a certain number of equipment in a chain. The selection of the source to be restored was done by turning on the power of the selected source and putting the equipment in standby between the source and the playback equipment. SUMMARY OF THE INVENTION It can be seen that there is a need in the digital world to connect any number of chain equipment to a rendering equipment.

In particular, it is desired that the inactive equipment of such a chain consumes little energy. This requirement is tending to be satisfied by providing electronic equipment comprising an output interface having a high rate output channel, an auxiliary medium rate bi-directional channel. , and a power relay pin; an input interface having a high rate input channel, a medium rate auxiliary bidirectional channel, and a power relay pin; and a management circuit capable of organizing the relaying of a flow from the input channel to the output channel, and the relaying of data between the auxiliary channels of the input and output interfaces. It includes a power source configured to activate the power relay pin of one of the interfaces, downstream interface, regardless of the power supply of the equipment. The interfaces and the management circuit are also powered from the power relay pin of the other interface, upstream interface. According to one embodiment, the power source is configured to supply the equipment itself or the power relay pin of the downstream interface on control of the management circuit in response to a command received by the auxiliary channel. the upstream interface. According to one embodiment, the high-speed channels are designed to convey digital video and audio signals and the management circuit is able to organize the transmission of digital audio signals through the auxiliary channel of the input interface. In addition, a method is provided for managing a plurality of equipment of the above-mentioned type connected in series by their input and output interfaces, comprising the following steps implemented by a master equipment device arranged upstream of the chain: identifying a target equipment in the chain; enable the power relay pin of the downstream interface of the master device; for each equipment disposed between the master equipment and the target equipment, send it via the auxiliary channel of its upstream interface an activation command of the power relay pin of its downstream interface; and send to the target equipment, through the auxiliary channel of its upstream interface, a power supply command of the equipment. A method of identifying several devices connected in a chain by their input and output interfaces, comprises the following steps implemented by a master equipment arranged upstream of the chain: activate the power relay pin of the downstream interface of the master equipment; for each slave unit in the chain, send it via the auxiliary channel of its upstream interface a command to activate the power relay pin of its downstream interface; and receiving by the auxiliary channel of the downstream interface of the master equipment identification data sent by the slave devices as the management circuits of their interfaces are powered. BRIEF DESCRIPTION OF THE DRAWINGS Other advantages and features will emerge more clearly from the following description of particular embodiments given by way of nonlimiting examples and illustrated with the aid of the attached drawings, in which: FIG. 1 shows schematically a link according to VESA DisplayPort standards; Figure 2 schematically shows a chain of audio / video equipment connected by DisplayPort links; Figure 3 shows schematically an embodiment of relay DisplayPort interfaces incorporated in a device and associated with a power source of the equipment; and Figs. 4a-4c show four states of the relay of Fig. 3 in establishing communication with a selected source. DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION In order to link several digital equipments in a chain, it is envisaged to use a link having a high speed unidirectional channel (capable of transmitting uncompressed high definition video), a bidirectional channel of average rate 25 (sufficient to transmit compressed audio), and a power relay line. The HDMI 1.4 and VESA DisplayPort standards define links that meet these needs. We will prefer the DisplayPort standard because it was partly designed to put equipment in a chain (up to 63 devices from version 1.2), which means that we already have 30 protocols and circuits that are suitable for placing in chain.

FIG. 1 schematically represents a DisplayPort link between a Tx transmitter and an Rx receiver. The link comprises up to four unidirectional broadband lines (Tx to Rx) ML_LnO to ML_Ln3 (from the English term "Main Link Lane" meaning main link channel); a bidirectional average flow line AUX_CH; unidirectional line (Rx to Tx) hot-plug detection Hot_Plug_Detect; and a DP_PWR power relay line. According to VESA DisplayPort version 1.2, the rate on each ML_Ln line can reach 5.4 Gb / s, and the AUX_CH line has a fast mode, designated F-AUX, with a bit rate of 720 Mb / s. The DP_PWR power relay is designed to carry a voltage of 3.3 V at 500 mA. The DisplayPort link was originally designed to connect monitors or other display devices to computer CPUs. An application envisaged for the auxiliary channel AUX_CH is to transmit to the central unit the signals coming from peripherals connected to the monitor, such as the keyboard, the mouse, a camera, a microphone, and other peripherals connected to USB jacks (or other ) provided on the monitor. This makes it possible to connect the monitor equipped with its peripherals by a single cable to the central unit.

It has also been envisaged to connect several chain monitors to the central unit. In this case, each monitor has an input interface and a DisplayPort output interface. The input interface of each monitor is designed to accept multiple video streams. The monitor extracts the stream that is intended for it and relays the others on its output interface, connected to the next monitor that performs a similar operation. The auxiliary channel is used in this case to identify the destination of the video streams, the identifiers and possibilities of the monitors that have been communicated to the central unit by the auxiliary channels when the monitors are powered up or connected. In the applications mentioned above, the power relay line DP_PWR is not used. One envisaged application of this line is to power a low consumption display device, such as an LCD display or a mini video projector.

Figure 2 schematically illustrates an example of audio / video equipment chaining El to E4 using DisplayPort links DP1 to DP3. For example, you want to connect a DVD player, an STB satellite demodulator, and an AVR audio / video amplifier to a TV set.

Each device is equipped with an input interface and a DisplayPort output interface, DP below. The notions of "input" and "output" are to be taken relative to the flow on the broadband lines ML_Ln. A device is put in the chain by connecting its output interface to the input interface of the preceding equipment, the equipment at the top of the chain being an audio / video reproduction device, the TV set in FIG. 3, capable of receiving the audio / video stream from any of the other devices, or several at the same time (split screen, windowing, mosaic). This digital chain, with the management circuits associated with the DP interfaces in each device, could be designed in the same way as an analog SCART-based channel, ie the user starts the process. equipment to watch, for example El, and puts all the equipment (E2) between the equipment to watch and the playback equipment (E3, E4) to sleep. The DP interfaces in standby equipment (E2), powered by the standby system, are configured in this mode to relay the signals from their incoming link to their outgoing link. The amplifier E3 retrieves the audio stream and relays only the video stream V1 to the television E4. In addition, the bidirectional auxiliary channels of the DP links may be used, for example, to transmit RC remote control signals received centrally by one of the equipment, here E3. In addition, the location of a medium rate receiver equipment, such as the amplifier E3, can be arbitrary. If the amplifier E3 is placed at the end of the chain, on the opposite side of the television, the audio stream intended for it can be transmitted to it by the auxiliary channels of the DP links. It is preferred for this purpose that the DP interfaces are at version 1.2 of the standard, allowing a flow amply sufficient for any audio stream on the auxiliary channel. It should be noted that such a channel could also be made from HDMI 1.4 links, with channels dedicated to the audio return and the remote control.

In this example of chaining, it was mentioned that equipment not used between the equipment watched and the playback equipment are put on standby, and not extinguished, so that their DP interfaces are powered to perform their relay function. Even if no equipment is used, it is desired that the DP interfaces transmit the remote control signals to power on a chosen equipment. However, many devices consume a significant amount of energy in standby. This is the case, for example, of a digital video recorder, or PVR, which must be able, even in standby, to record a program. If you have not programmed a recording, you want to be able to turn off the equipment, or put it in a deep sleep state that only feeds the circuits necessary for its remote power-up. It turns out that the current required for the operation of the DP interfaces (as for HDMI interfaces) is relatively important, because these interfaces are designed to transmit signals at high speed, up to 21.6 Gb / s for an interface. DisplayPort 1.2. A current of "deep sleep" is not enough to feed them. The following is a solution to supply only the required interfaces in a chain, while ensuring a minimum power consumption, or extinction, unused equipment. This solution will also enable remote start of equipment even if the intermediate equipment in the chain are de-energized or disconnected from any power source. FIG. 3 schematically shows an embodiment of a DisplayPort relay 10, incorporated in a device and associated with a power source 12 of the equipment. The lower part of the relay 10 corresponds to the input interface DPi. The high-speed input lines receive an AVi audio / video stream from the output interface of the next equipment in the chain. This stream AVi, shaped by a reception circuit Ln Rx, arrives at a first input of a multiplexer 14. A second input of the multiplexer 14 receives a local audio / video stream, that is to say from equipment itself, via a CONV conversion circuit.

The multiplexer 14 is controlled by a management circuit 16 which manages in particular the auxiliary channels AUXi of the input interface and AUXo of the output interface. This output interface DPo is represented at the upper part of the relay 10. The output of the multiplexer 14 supplies the outgoing audio / video stream AVo via a transmission circuit Ln Tx. The power relay line DP_PWRo of the output interface is intended to supply the power required for the relay 10. In other words, it is not intended to supply the relay 10 with the power supply. internal 12 of the equipment. The voltage (3.3V) and current (500mA) values provided for this line by the DisplayPort standards allow this. The supply relay line DP_PWRi of the input interface is, in turn, powered by a dedicated output of the power source 12 of the equipment, under control of the management circuit 16. The source 12 is further provided, under control of the circuit 16, to supply the general power supply PWR of the equipment, or, if appropriate, a standby power supply SBY. In the absence of control by the management circuit 16, the source 12 provides no power. The power required for the source 12 to manage the commands received from the management circuit 16 may be provided, as shown, by the line DP_PWRo. Thus, the source 12 can be completely disconnected from a main source, such as the power grid. The management circuit 16 may be further provided, as shown, for directing a local audio stream A Loc, or even a compressed video stream, to the auxiliary channel AUXi of the input interface. This makes it possible to have an audio reproduction equipment at the end of the chain, and to transmit to it via the auxiliary channels audio signals in the opposite direction of the channels ML_Ln. Furthermore, the equipment can be provided with various interfaces, such as USB or Ethernet, the circuit 16 redirects and provides through the auxiliary channels input and output interfaces. Figures 4a to 4d show different states of a relay of the type of Figure 3 in use in a chain of equipment. The powered elements are represented in solid lines, while the non-powered elements are shown in dashed lines. For the sake of clarity, the high-speed channels of the relay, which behave from the point of view of their power supply, such as the auxiliary channels and the management circuit 16, are not represented. Each intermediate equipment of the chain is provided with a similar relay. Extreme equipment may only be equipped with the input interface or the output interface, depending on whether the equipment is at the head or end of the line. One of the equipment, preferably the one located at the head of the chain, is master and will be provided to manage the other equipment, slaves, of the chain. The master equipment is preferably chosen from those that are necessarily used, for example the television E4 (FIG. 2). It could also be the amplifier E3, in which case it would be placed at the head of the chain, in front of the TV. Figure 4a illustrates a relay of a slave device in an initial state, where all the equipment in the chain is de-energized. Neither the relay nor the equipment itself is powered. The power source 12 is inactive. There is no energy consumption in the equipment. In FIG. 4b, an upstream equipment, for example the master equipment, supplies the line DP_PWRo. The relay elements are powered and ready to operate. In addition, the master equipment transmits on the auxiliary channel an identifier of the target equipment to be activated. This identifier can be the position of the equipment on the chain, each equipment having previously memorized its position. The identifier may also be a unique universal identifier that the master equipment has previously stored. In Figure 4c, it turns out that the equipment is not the target equipment because the management circuit has not recognized the identifier. It is therefore further down the chain. The management circuit controls the source 12 so that it feeds the line DP_PWRi of the input interface DPi. This line feeds the relay of the next downstream equipment, which is found in the state of Figure 4b. The relay is configured to operate as a bridge, that is to say that the multiplexer 14 (FIG. 3) is set to transmit the incoming stream AVi on the output interface DPo. The management circuit 16 further transmits on the AUXi channel the identifier that it has received by the AUXo channel.

In Figure 4d, the equipment turns out to be the target equipment. The management circuit, which has recognized the identifier arriving on the AUXo channel, controls the source 12 to power the equipment. At the same time, the multiplexer 14 (FIG. 3) is set to transmit the local stream AV Loc on the output interface. If it turns out that there is an audio receiver further down the chain, the local audio stream is routed to the AUXi auxiliary channel of the input interface. The steps of FIGS. 4b and 4c for the downstream equipment are then repeated until they reach the audio receiver. According to an alternative to the step of FIG. 4d, the equipment has switched from the off state to the standby state, for example in the case of a digital video recorder programmed for recording. Of course, to define a target equipment, it is preferable that the master equipment knows beforehand the composition of the string. The master can take cognizance of the equipment of the chain during a discovery phase, which can be carried out systematically each time the master equipment is powered up or punctually at the request of the user each time he modifies chain. During this phase, one proceeds according to the steps of Figures 4a to 4c, to activate gradually all relays of equipment in the chain, as if the master sought to activate equipment located at the end of the chain. Each activation of a relay, the master equipment is notified by the auxiliary channels, according to the protocols defined by the DisplayPort standard. These protocols are provided in particular for the equipment that is interconnected to identify each other. The credentials exchanged may contain a unique universal identifier, the make and model of the equipment, the serial number, the recognized flow and flow formats ... Thus, the master equipment receives this information and can constitute a table of the equipment of the chain and their positions. The master equipment may further communicate the positions to the slave devices by the auxiliary channels for storage, for example in their management circuit 16. The slave devices themselves could maintain downstream equipment tables, of which they receive the identifiers by their AUXi channels.

Powering off the entire chain can be performed as follows. The user starts by turning off the master equipment. This disables the DP_PWRi line of its input interface DPi. As a result, the relay of the next downstream equipment is no longer powered. As a result, the power source 12 of this downstream equipment is deactivated, including its DP_PWRi line. The equipment of the chain is thus turned off step by step, starting from the master equipment, at the head of the chain, towards the equipment at the end of the chain. According to this power-down procedure, any communication with the master equipment is interrupted immediately, so that equipment that should remain idle, for example to record at a scheduled time, would also be turned off. To avoid this, a "concerted" extinguishing procedure is preferred. The master equipment controls the extinction step by step starting with the last active equipment at the end of the chain, through the auxiliary channels. It can then establish a dialogue before power off between the master equipment and the slave equipment. For example, the slave device may ignore the power off command and remain in standby to perform a recording, but respond to the chain as if it were powered off, including stopping power to its pin DP_PWRi .

Claims (5)

REVENDICATIONS1. Electronic equipment comprising: - an output interface having a high speed output channel (AVo), a medium rate auxiliary bidirectional channel (AUXo), and a power relay pin (DP_PWRo); an input interface having a high rate input channel (AVi), a medium rate auxiliary bidirectional channel (AUXi), and a power relay pin (DP_PWRi); and - a management circuit (16) able to organize the relay of a flow from the input channel to the output channel, and the data relay between the auxiliary channels of the input and output interfaces; characterized in that it comprises a power source (12) configured to activate the power relay pin (DP_PWRi) of one of the interfaces, downstream interface, regardless of the power supply of the equipment, and the interfaces and the management circuit are powered from the power relay pin (DP_PWRo) of the other interface, upstream interface. 2. Equipment according to claim 1, wherein the power source (12) is configured to power the equipment itself (PWR) or the power relay pin (DP_PWRi) of the downstream interface on command of the management circuit (16) in response to a command received by the auxiliary channel (AUXo) of the upstream interface. 3. Equipment according to claim 1, wherein the high-speed channels are designed to convey digital video and audio signals and the management circuit is able to organize the transmission of digital audio signals through the auxiliary channel (AUXi) of the input interface. 4. A method of managing multiple devices according to claim 2 connected in series by their input and output interfaces, comprising the following steps implemented by a master equipment (E4) arranged upstream of the chain: - identify a device target in the chain; 11 - activate the power relay pin (DP_PWRi) of the downstream interface of the master device; for each equipment placed between the master equipment and the target equipment, send it via the auxiliary channel (AUXo) of its upstream interface a command to activate the supply relay pin (DP_PWRi) of its downstream interface; and - send to the target equipment, via the auxiliary channel (AUXo) of its upstream interface, a power supply command of the equipment. 5. A method of identifying several devices according to claim 2 connected in series by their input and output interfaces, comprising the following steps implemented by a master equipment (E4) arranged upstream of the chain: - activate the power relay pin (DP_PWRi) from the downstream interface of the master equipment; - For each slave unit in the chain, send it via the auxiliary channel (AUXo) of its upstream interface an activation command of the power relay pin of its downstream interface; and - receiving through the auxiliary channel of the downstream interface of the master equipment identification data sent by the slave equipment as the management circuits (16) of their interfaces are powered.