Selected mode signal forwarding between serially chained devices

Abstract

SOLUTION: In described examples, a circuit (500) is adapted to receive an input signal at a local port (562) or a first system port (582). A transceiver (522) is configured to enter a first mode in response to a local wakeup signal and is configured to transmit a system wakeup signal at a second system port (592) in response to the local wakeup signal. A controller (524) is configured to generate the local wakeup signal in response to an energy detected signal. An energy detector (526) is coupled to the first system port (582) and the local port (562) and is configured to generate the energy detected signal in response to detection of energy of one of the first system input signal and the local input signal received by the transceiver (522) in the second mode.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] In some electronic systems, various components are coupled by a physical layer that includes connectors and electrical wiring. In some applications, the limits on the functionality of the various components may be limited by the cost, size, and number of connectors and / or the cost, size, and number of individual wires in the electrical wiring. Summary of the Invention

[0002] In the described example, the circuit is adapted to receive an input signal at the local port or the first system port. The transceiver is configured to enter the first mode in response to the local wake-up signal and to transmit a system wake-up signal at the second system port in response to the local wake-up signal. The controller is configured to generate the local wake-up signal in response to the energy detect signal. The energy detector is coupled to the first system port and the local port and configured to generate the energy detect signal in response to detecting energy in one of the first system input signal and the local input signal received by the transceiver in the second mode. 9 [Brief description of the drawings]

[0003] [Figure 1] FIG. 1 is a system diagram illustrating an example vehicle including an example system adapted to selectively redirect transmissions between serially chained devices of the example system.

[0004] [Diagram 2] 1 is a diagram of an example transmission in an example system adapted to selectively redirect transmissions between serially chained devices.

[0005] [Diagram 3]1 shows a block diagram of an example multi-stream generator adapted to aggregate input streams in an example system adapted to selectively forward transmissions between serially chained devices.

[0006] [Figure 4] FIG. 1 is a block diagram of an example system including at least one stream disaggregator adapted to selectively forward transmissions between serially chained devices.

[0007] [Diagram 5] 1 is a block diagram of an example system including at least one bus unit adapted to generate and transfer a system wake-up signal between serially chained bus units.

[0008] [Figure 6] 6 is a flow chart of an example method of issuing a wake-up signal in the example system of FIG. 5.

[0009] [Figure 7] 6 is a flow chart of an example method of wake-up signal detection and wake-up signal processing of the example system of FIG. 5.

[0010] [Figure 8] FIG. 2 is a block diagram of a first example wake-up signal processing scenario in an example system.

[0011] [Figure 9] FIG. 11 is a block diagram of a second example wake-up signal processing scenario in an example system.

[0012] [Figure 10] FIG. 11 is a block diagram of a third example wake-up signal processing scenario in an example system.

[0013] [Figure 11]FIG. 13 is a block diagram of another example system including at least one stream disaggregator adapted to selectively forward transmissions between serially chained devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In the drawings, like reference numerals indicate like elements and the various features are not necessarily drawn to scale.

[0015] Various electronic systems use components that are coupled together to form the system. As the functionality of the system increases, the complexity of the interconnects increases. As more functionality is added to a system (e.g., in response to increased integration and processing power), the number of terminals on the connector increases, which in turn increases the size, complexity, and / or cost of the connector.

[0016] Some electronic systems may be installed on a transportation platform (such as an aircraft or automobile). Constraints in the construction of the mobile platform (e.g., due to human factors, safety considerations, aerodynamic characteristics, etc.) may limit the space available for the connectors and cabling of the electronic system. Also, access to the connectors and cabling (e.g., for testing, replacement, and / or repair) may be limited (which increases operational costs), such as when the electronic system is installed in the dashboard of a vehicle (which may include at least one airbag).

[0017] An example of an electronic system that may be installed in a mobile platform is an automobile "infotainment" system, in which video data may be generated (or transmitted) by a control unit (e.g., a head unit or other data source). The generated video data may be transmitted to multiple display panels (e.g., a head-up display, an instrument cluster, and a central instrument display). Various cables / connectors are disposed between the control unit and each of the different displays to send different types of display data from the control unit to the different displays. A cable adapted to carry signals between two units (such as a display and a control unit) has a first connector (e.g., a first set of connectors) adapted to connect to a first mating connector of the first unit, a second connector (e.g., a second set of connectors) adapted to connect to a second mating connector of the second unit, and a cable harness (e.g., a flexible cable harness) having insulated wiring arranged to electrically couple signals (e.g., unidirectional and / or bidirectional signals) between the first connector and the second connector.

[0018] In one example, multiple displays may be connected to a control unit in a one-to-multiple configuration, with the connecting cables converging to one location on the control unit (e.g., on the face of the control unit). For example, a master control unit may include a connector and cable pair for communicating with each slave device in the system (e.g., in a star network topology). The convergence of connectors and cables at the control unit creates mechanical spacing issues, and the convergence of multiple connectors located side-by-side occupies significant space in the automobile. Also, the video information (e.g., at least one video stream) from the control unit is high-resolution data that is continuously streamed to each display via a respective connector / cable pair. Because of the point-to-point connection of the star topology, each video stream does not need to be associated with or identified by a networking address. Traditionally, the video data from the head unit transmitted to the display is high-resolution data that is continuously streamed and is not in a format that can be easily networked as in some other data networking applications.

[0019] As described herein, an example system is adapted to selectively route transmissions between serially-chained devices of the example system. For example, the example system may include a control unit coupled to a serial chain of display units (e.g., one end of the serial chain). An example multi-stream generator may be coupled to an output of the control unit such that the example multi-stream generator may encode (e.g., encapsulate) video data from multiple streams into a format adaptable to various types of displays in the serial chain (e.g., daisy-chained displays). Congested mechanical spacing issues due to cable / connector convergence at the control unit location may be mitigated by arranging the example system components as shown in FIG. 1.

[0020] 1 is a system diagram illustrating an example vehicle including an example system adapted to selectively forward transmissions between serially chained devices of the example system. Generally, system 100 is an example system including a host vehicle 110. An example multi-display system 120 may be installed in the host vehicle 110. The example multi-display system 120 may include any number of displays, one end of which may be connected in a serial chain to a control unit.

[0021] An example multi-display system 120 may include a control unit (e.g., head unit 122), a first display (e.g., instrument cluster display CLUSTER 124), a second display (e.g., head-up display HUD 126), and a third display (e.g., central instrument display CID 128). An example multi-display system may include one or more head units 122. The head units 122 are adapted to receive sensor data (e.g., from a camera or instrument sensor) and generate a video stream in response to the sensor data. Each head unit 122 transmits at least one generated video stream, each of which is received by a multi-stream generator 123. However, the use of multiple head units complicates the system, creates additional failure nodes, increases costs, and occupies more space in a limited area, for example.

[0022] The multi-stream generator 123 (MG) may include an input (e.g., a video input) coupled to (e.g., may be included in) the head unit 122 and may include an output coupled to an input of the stream disaggregator 125 (e.g., via cable 133). In some examples, the multi-stream generator 123 may receive video streams from each head unit 122. In some examples, the multi-stream generator 123 may receive video streams from at least one head unit 122 (e.g., such that one or more video streams may be generated by the head unit 122 for stream aggregation by the multi-stream generator 123).

[0023] The stream disaggregator 125 may have a first output (e.g., a local output) that is coupled to (e.g., may be included in) the display CLUSTER 124, and may have a second output (e.g., a system output) that is coupled to an input of the stream disaggregator 127 (e.g., via cable 135).

[0024] The stream disaggregator 127 may include a first output (e.g., a local output) that is coupled (e.g., may be included) in the display HUD 126, and may include a second output (e.g., a system output) that is coupled (e.g., via cable 137) to an input of the stream disaggregator 129.

[0025] The stream disaggregator 129 (SD) may have a first output (e.g., a local output) that is coupled to (e.g., may be included in) the display CD 128, and may have a second output (e.g., a system output) that is optionally coupled (e.g., via another cable, not shown) to an input of an optional stream disaggregator (not shown) for display. Other stream disaggregators may be serially coupled to the tail of a serial chain connecting serially chained displays (e.g., the tail of the serial chain is opposite the end of the serial chain connected to the head unit 122) (an example wiring network is described hereinafter in connection with FIG. 4).

[0026] Compared to a star topology display system for three displays (which includes three cables and respective connectors that converge at a location on the control unit), the serially chained display system described herein reduces space and mechanical constraints (e.g., resulting in constraints reduced to the space of one connector / cable connected at the head unit 122).

[0027] The multi-stream generator 123 is arranged to encode high-resolution real-time video data (including video-related data) into a packet format. The operation of the multi-stream generator is described hereinafter with reference to FIG. 3. The multi-stream generator 123 may be arranged as a serializer (e.g., adapted to output video data serially, where the video data may be received asynchronously by the multi-stream generator 123 in serial or parallel format) and / or may be arranged to output video data in parallel. Each packet may include an identifier (e.g., a stream identifier) ​​to identify the particular video stream that was encoded and / or to identify the destination of the packet (e.g., to identify the display to which the packet is addressed). The identifier may be parsed by the stream disaggregators according to a mode (e.g., default or programmed configuration) associated with the respective stream disaggregator. Each packet is received by at least one stream disaggregator for forwarding (and / or decoding / deserialization).

[0028] The stream disaggregators (e.g., 133, 135, and 137) are arranged to receive packets (e.g., having an identifier to indicate a destination display) and select between a stream disaggregator first output (e.g., a local output for combining the information to a locally combined display) and a stream disaggregator second output (e.g., a system output for forwarding the information to at least one other stream disaggregator).

[0029] 2 is a diagram of an example transmission in an example system adapted to selectively forward transmissions between serially chained devices. Generally, transmission 200 is an example transmission arranged in a packet format. The example transmission may include streaming data for streaming video. The streaming video data may include audio data combined with (e.g., synchronized with) the streaming video. The streaming data may include content for displaying moving images and / or still images.

[0030] In a first example packet (such as packet 210), packet 210 includes a control (CTL) field 211, a payload (e.g., STREAM_PAYLOAD) field 212, an error correction code (ECC) field 213, a stream / destination (STRM) field 214, a reserved field 215, and a continuation (CONT) field 216.

[0031] Field 211 may indicate whether the stream payload (e.g., field 212) contains command data or streaming data. The command data contained in field 212 may include, for example, a start command to start playing a selected video stream, a configuration command, for example, to configure a mode and select a specific protocol (e.g., from among various proprietary or industry standards) for a particular stream disaggregator to communicate with a connected local display (e.g., a local display to which it is pointed and cabled) and set a playback channel for a particular display (e.g., for playing at least one selected stream that includes a selected STRM field 214 value), a routing command, which is a command to select at least one stream to be routed to a local display (e.g., of a particular stream disaggregator), and / or a forwarding command to select at least one stream to be forwarded to another stream disaggregator (so that the first disaggregator forwards the selected stream from the first stream disaggregator to a second disaggregator and head unit downstream). In one example, configuration data may be pre-programmed into a particular stream disaggregator (e.g., during system integration such as at an automobile factory) (e.g., thereby reducing configuration time) and command data may be used to reprogram a given configuration during operation (e.g., the given configuration may be pre-programmed or programmed during operation).

[0032] The streaming data included in field 212 may include video (e.g., still or dynamic video) information, audio information, or a combination thereof. The resolution of the streaming data may be selected to provide video (and / or sound) quality equivalent to a particular display and / or target functionality. The streamed video data may include pixel information. An example pixel may include 8 bits of red information, 8 bits of green information, and 8 bits of blue information. The number of pixel rows and columns may be selected to generate video frames corresponding to the capabilities of a particular display screen. The video frames may be encoded as transmitted symbols and / or compressed information for transmission and subsequent decoding by a target display. The video frames may be streamed (e.g., transmitted as a timed sequence of video frames associated with a particular video "feed").

[0033] Field 213 includes an ECC code (e.g., for error detection and correction). The number of bits in field 213 may be increased (e.g., from one parity bit to a larger number of bits) to provide a higher level of detection and even correction of errors that may occur in packet 210 being transmitted and received. A receiver may evaluate the ECC code of a received packet against other bits of the received packet to, for example, correct a corrupted packet and / or request a retransmission of the original packet (e.g., original packet data) (e.g., by transmitting upstream). The length of the ECC field may be selected to provide a level of performance for a particular functionality (e.g., for a dashboard display compared to a less critical infotainment display unit for viewing by rear seat passengers).

[0034] Field 214 includes information useful for identifying a display to which a received packet is to be routed. The number of bits in field 214 is sufficient to uniquely identify a particular stream (e.g., video channel) and / or display (e.g., at least one display for consuming and playing the stream associated with the received packet). In a first example, field 214 includes enough bits to identify a particular stream (e.g., a channel number) and the stream disaggregator is programmed (e.g., via a configuration command described herein) to route the received packet to at least one display (e.g., which is set to a channel number so that one or more displays may play the same stream). In a second example, field 214 includes enough bits to identify a particular display (e.g., an instrument panel or an electronic side-view "mirror" display) on which a particular received packet is to be displayed. In a third example, field 214 includes enough bits to indicate a code for selecting a predefined routing configuration for consuming (e.g., routing to a local display) and / or forwarding a particular received packet. In a fourth example, field 214 includes sufficient bits to include a combination (eg, some or all combinations) of the functionality described herein for the first, second, and third examples.

[0035] Field 215 is reserved for carrying data for undefined (e.g., unpublished or not yet published) purposes. For example, the reserved fields do not necessarily carry data useful in earlier systems, but may be used to carry information useful in later systems, thereby avoiding the need to change packet length to make room for carrying information that is implemented later. Field 215 may contain enough bits to extensively transmit and receive packets having a common packet length (e.g., according to a subsequent protocol standard associated with at least one existing FPD standard, or according to a proprietary protocol that is later developed).

[0036] Field 216 indicates whether the packet is the last packet in the stream. In an example where field 216 indicates that the packet is the last packet in the stream, a display consuming the packet may take an action in response to an indication that the particular received packet is the last packet in the stream. An example action (e.g., that may be taken in response to an indication that the particular received packet is the last packet in the stream) may be a provisional action (e.g., a quickly reversible action) such as dimming a display selected to display the stream associated with the particular received packet. Packet transmission and forwarding is described hereinafter with reference to FIG. 4.

[0037] In a second example packet (such as packet 220), packet 220 includes a control (CTL) field 221, a stop (e.g., STREAM_STOP) field 222, an error correction code (ECC) field 223, a stream / destination (STRM) field 224, and a reserved field 225.

[0038] Field 221 may indicate whether the stream payload includes command data (such as a stop command in field 222). The command data included in field 222 may include a stop command. In response to a transmitted stop command, the downstream stream disaggregator and display identified by field 224 may power down, reinitialize, and / or reallocate previously allocated resources to display the stream associated with the received packet (e.g., the packet including the stop command). In one example, field 222 may include a command to terminate operation of programmable hardware adapted to display video information (e.g., a code in stop field 222 may indicate that the instant packet is the last packet in the video stream indicated by field 224).

[0039] Field 223 contains ECC code (eg, for error detection and correction), such as the code contained in field 213 .

[0040] Field 224 is a field similar to field 214 and may contain information to indicate which stream the packet is associated with and / or to indicate the display to which the packet should be sent.

[0041] Field 225 is a field similar to field 215. A continue field, such as field 216, need not be implemented in a packet that contains a stop field, since the presence of the stop field can be used to determine that the packet containing the stop field is the last packet in a stream. By using the stop field to indicate that the stream should be terminated, the space used by the continue field in a packet with a stop field is freed up and reserved for potential future use (e.g., future use for any purpose).

[0042] 3 is a block diagram of an example multi-stream generator adapted to aggregate input streams in an example system adapted to selectively forward transmissions between serially-chained devices. The multi-stream generator 300 is an example multi-stream generator that may be disposed on a substrate 302. The multi-stream generator 302 includes an input (e.g., receiver 310) adapted to receive at least one video stream from a selected head unit, and an output (e.g., transmitter 390) adapted to forward a packetized video stream to a first stream disaggregator. The packetized video stream may be generated (e.g., sourced) by a video source (such as a digital camera) according to a MIPI (Mobile Industry Peripheral Interface) Camera Serial Interface (CSI). The video source for generating the example video 0-video 7 streams may include a sensor (e.g., sensor 402), which may include various cameras, such as backup or side-view cameras, each arranged to generate a respective video stream. The video source for generating the example video 0 through video 7 streams may also include the head unit (e.g., head unit 401) itself, which may generate at least one video stream for display in response to a sensor, such as sensor 402 (described below in connection with FIG. 4).

[0043] In one example, the clock generator 304 is disposed on the substrate 302 and is adapted to generate clock signals such as a video pixel clock (VP clock), a video link layer clock (vclk_link), a frame clock (clk_frame), and a lane clock (clk_div40). In some examples, some of the clock signals may be generated by circuit elements not included on the substrate 302. The architecture of the multi-stream generator is also scalable (e.g., by powers of two) such that the multi-stream generator may aggregate (address by including a sufficient number of bits in fields 214 and 224) a selected number of video streams (e.g., eight or more). In some examples, the receiver may include a transmitter such that information may be transmitted (e.g., in a second, opposite direction) from the example receiver 310. The multi-stream generator 300 may be adapted to transmit data bidirectionally (e.g., at 165 megabits per second upstream and 13 gigabits per second downstream). An example of bidirectional transmission / reception of transmitted data is described in U.S. Patent No. US9,363,067, issued June 7, 2016, entitled "Data Signal Transceiver Circuitry for Providing Simultaneous Bidirectional Communication Over a Common Conductor Pair," which is incorporated herein by reference. [Patent Document 1] U.S. Patent Number US9,363,067

[0044] For a first video stream (e.g., video In0) in the exemplary multi-stream generator 300, a pixel aligner 312 is adapted to sample the first video transmission to align (e.g., synchronize) the sampled data with an internal clock (e.g., VP Clock) of the multi-stream generator 300, and to generate horizontal synchronization (hsync) and vertical synchronization (vsync) information (e.g., for identifying pixel locations of the received pixel data). The sampled data is verified by checking (and possibly correcting) errors with a 32-bit cyclic redundancy checker (CRC) 314. The verified information is stored in a video buffer 322 and temporally associated with the hsync and vsync information. Thus, for example, start and stop packets may be associated with the beginning and end of a displayed video frame, respectively. Video streams may be received (e.g., from a head unit) as serial or parallel streams, accessed from a system memory (e.g., frame memory), and / or transmitted / accessed by a combination thereof.

[0045] Stream mapper 330 is adapted to receive stream (e.g., video In0 stream) information and associated hsync and vsync signals from video buffer 322. In response to the video buffer 322 information and associated hsync and vsync signals, stream mapper 330 is configured to associate a particular video stream with a particular display (e.g., by setting a value of a STRM field, such as field 214 or field 224).

[0046] The lane-0 link layer 332 is arranged to generate signals (for example) adapted to control physical layer parameters for transmitting data on lane-0 in accordance with a system protocol (for example, the FPD protocol described hereinafter). The lane-1 link layer 334 is arranged to generate link control signals (for example) adapted to control physical layer parameters for transmitting data across lane-1 in accordance with a system protocol. The link control signals may be generated synchronously to (for example, in response to) a video link layer clock.

[0047] Packets from a particular stream (e.g., video In0 stream) may be transmitted over either lane-0 or lane-1 in response to an allocation made by a transmit distributor (TX distributor) 342. The TX distributor 342 may allocate at least one transmit lane so that pixels of a video frame may be transmitted at a rate sufficient to achieve the frame rate of the display indicated by the STRM field. A first output of the TX distributor 342 is coupled to transmit lane-0 data to an input of the framer 352, and a second output of the TX distributor 342 is coupled to transmit lane-1 data to an input of the framer 354. The pixels of the video frame may be transmitted synchronously with a frame clock. In some examples, a particular lane may be associated with a respective display (e.g., as a system design choice), such that a video stream may be associated with (e.g., forwarded to) a respective display. In some examples, the lanes may be dynamically allocated based on network traffic such that the lanes carry different video streams (e.g., where a stream disaggregator is adapted to associate received packets of a particular video stream with a particular display and, in response, forward / transmit packets of a given video stream toward the correct display).

[0048] Framer 352 and framer 354 are adapted to generate transmission frames according to a system protocol, such as a low-voltage differential-signaling (LVDS) protocol. The system protocol may be an LVDS standard, such as a Platform Panel Display Link (FPD) protocol (e.g., FPD-Link I, FPD-Link II, FPD-Link III, and any subsequent standard related to at least one existing FPD standard). The system protocol may also include "sub-LVDS standards," current-mode and / or voltage-mode drivers / receivers, and other low-power, high-speed signaling protocols (including Gigabit Multimedia Serial Link GMSL). The FPD framer 362 is adapted to align data for transmission within a transmission frame, the FPD encoder 372 is adapted to encode the aligned data as symbols for transmission within the transmission frame, and the FPD frame physical aligner (FRAME PHY ALIGN) 382 is adapted to buffer the encoded symbols for synchronous transmission by a transmitter 390 over lane-0 (e.g., clocked by a lane clock). The FPD framer 364 is adapted to align data for transmission within a transmission frame, the FPD encoder 374 is adapted to encode the aligned data as symbols for transmission within the transmission frame, and the FPD frame physical aligner (FRAME PHY ALIGN) 384 is adapted to buffer the encoded symbols for synchronous transmission by a transmitter 390 over lane-1. The encoded symbols may be decoded by a receiver, such as receiver 422, and encoded by a stream forwarder (e.g., a stream transmitter), such as stream forwarder 426, as described hereinafter.

[0049] For a second video stream (e.g., Video In7) in the exemplary multi-stream generator 300, a pixel aligner 316 is adapted to sample the video transmission, align the sampled data to an internal clock of the multi-stream generator 300, and generate horizontal synchronization (hsync) and vertical synchronization (vsync) information. The sampled data is verified by checking for errors with a 32-bit cyclic redundancy checker (CRC) 318. The verified information is stored in a video buffer 324 and temporally associated with the hsync and vsync information, so that, for example, start and stop packets can be associated with the beginning and end, respectively, of a video frame to be displayed.

[0050] Stream mapper 330 is adapted to receive stream (e.g., video In7 stream) information and associated hsync and vsync signals from video buffer 324. In response to the video buffer 324 information and associated hsync and vsync signals, stream mapper 330 is configured to associate a particular video stream with a particular display (e.g., by setting a value of a STRM field, such as field 214 or field 224).

[0051] Lane-2 link layer 336 is arranged to generate signals (for example) adapted to control physical layer parameters for transmitting data on lane-2 in accordance with a system protocol. Lane-3 link layer 338 is arranged to generate signals (for example) adapted to control physical layer parameters for transmitting data via lane-3 in accordance with a system protocol.

[0052] Packets from a particular stream (e.g., the video In7 stream) may be transmitted over either lane-2 or lane-3 in response to an allocation made by a transmit distributor (TX distributor) 344. The TX distributor 344 may allocate at least one transmit lane so that pixels may be transmitted at a rate sufficient to achieve the frame rate of the display indicated by the STRM field. A first output of the TX distributor 344 is coupled to transmit lane-2 data to an input of a framer 356, and a second output of the TX distributor 344 is coupled to transmit lane-1 data to an input of a framer 358.

[0053] Framer 356 and framer 358 are adapted to generate transmission frames according to a system protocol, such as a Low Voltage Differential Signaling (LVDS) protocol. The system protocol may be an LVDS standard, such as the Flat Panel Display (FPD) Link Protocol, Revision 4. FPD framer 366 is adapted to align data for transmission within a transmission frame, FPD encoder 376 is adapted to encode the aligned data as symbols for transmission within the transmission frame, and FPD frame physical aligner (FRAME PHY ALIGN) 386 is adapted to buffer the encoded symbols for synchronous transmission by transmitter 390 over lane-2. The FPD framer 368 is adapted to align data for transmission within a transmission frame, the FPD encoder 378 is adapted to encode the aligned data as symbols for transmission within the transmission frame, and the FPD frame physical aligner (FRAME PHY ALIGN) 388 is adapted to buffer the encoded symbols for synchronous transmission by the transmitter 390 via lane-3.

[0054] Other video inputs (e.g., Video In2 through Video In6), lane outputs (e.g., Lane-4 through Lane-15), and circuit elements may be included so that the system bandwidth is sufficient to handle (for example) more displays (e.g., for instrument, side and rear view, navigation, passenger infotainment systems) and / or higher resolutions. As described hereinafter in connection with FIG. 4, the outputs (e.g., multi-stream outputs) are coupled to at least one stream disaggregator for coupling selected video streams to respective local displays. While local displays need not be coupled to stream disaggregators, wiring requirements (e.g., number of connectors, cables, and conductors) in a system with multiple displays and video streams increases to wire local displays that are not coupled to a stream disaggregator.

[0055] 4 is a block diagram of an example system including at least one stream disaggregator adapted to selectively forward transmissions between serially-chained devices. For example, system 400 is an example system including head unit 401, multi-stream generator 410, stream disaggregator 420 (e.g., locally coupled to local display 404 via cable 405), stream disaggregator 430 (e.g., locally coupled to local display 406 via cable 407), and stream disaggregator 440 (e.g., locally coupled to local display 408 via cable 409). Stream disaggregators 420, 430, and 440 may be adapted to transmit data bidirectionally (e.g., at 165 megabits per second upstream or 13 gigabits per second downstream).

[0056] In one example, the head unit 401 is coupled to receive sensor information from the sensors 402. The sensors 402 can be a set of sensors associated with the electronic systems of a vehicle (e.g., the vehicle 110). Such sensors can include sensors adapted to sense the location of driver controls (e.g., gear shift, lights, steering wheel, turn signal lever, and other controls), vehicle attributes (e.g., speed, gas level temperature, fuel flow, tire pressure, seat belts, and other attributes), and positioning (e.g., radar, satellite navigation, cameras, lane and curve sensors, and other related information). The head unit 401 is adapted to generate output information (e.g., video information) in response to the sensor information. Additional head units 401 can be coupled between the various sensors 402 and the multi-stream generator 410.

[0057] The head unit 401 is adapted to generate video information for display on a local display 404 (e.g., this may be the CLUSTER 124), a local display 406 (e.g., this may be the head-up display HUD 126), and a local display 408 (e.g., this may be the central instrument display CID 128). For example, the head unit may generate a first video stream of an operational vehicle dashboard (e.g., for displaying on a display panel for replacing a mechanical gauge), a second video stream for the HUD (e.g., for displaying navigation information on a virtual screen on the windshield), and a third video stream for the CID (e.g., for displaying real-time images from a rear-facing backup camera). The head unit 401 is adapted, for example, to output the video streams as individual bitstreams.

[0058] The multi-stream generator 410 is a multi-stream generator such as the multi-stream generator 300 described above. The multi-stream generator 410 is coupled to a video output (e.g., each of the video outputs) of the head unit 401 and is adapted to combine independent video streams (e.g., at least two) of the video streams received from the head unit 401 into an integrated (e.g., multi-stream) video stream using a system protocol. The multi-stream generator is adapted to packetize information from the integrated video stream (e.g., including at least two video streams) and transmit the integrated video stream (multi-stream). Thus, the multi-stream generator is arranged as a source node of the integrated video stream.

[0059] Each individual packet (generated by the multi-stream generator) includes an identification field, such as a STRM identifier, that may identify a selected display (e.g., an addressed display and / or an addressed node) as the destination of the packet. The multi-stream generator 410 is adapted to couple the encoded packets to a source output (e.g., of a source node) of the multi-stream generator 410. A first cable (411) is connected between the multi-stream generator 410 (e.g., a source node) and a first stream disaggregator (e.g., stream disaggregator 420). The first cable includes sufficient conductors (and associated insulation / shielding) to carry information for all lanes (e.g., at least one lane) over which video information is transmitted.

[0060] The stream disaggregator 420 includes a local link controller 421, stream inputs (such as receiver 422), a stream selector 423, a demultiplexer (DEMUX) 424, and a switch 427 (which includes a local exporter 425 and a stream forwarder 426). The receiver 422 may include a physical layer receiver, the local exporter 425 may include a physical layer driver, and the stream forwarder 426 may include a physical layer driver. The receiver 422 has a receiver output. The receiver 422 has a receiver input adapted to receive input data (e.g., an aggregated video stream) from an output of a source node (e.g., multi-stream generator 410). The input data may be (and / or may include) an incoming packet that includes an identification field, and the incoming packet is sent by the source node. The input data may be received as serial or parallel data. The input data is received according to a system protocol (e.g., FPD protocol) that is different from a local protocol (e.g., eDP protocol described hereafter).

[0061] The stream selector 423 includes a selector output. The stream selector 423 is coupled to a receiver output (e.g., of the receiver 422), and the stream selector 423 is configured to generate a destination indication at the selector output (e.g., of the stream selector 423). For example, the stream selector 423 is adapted to monitor the receiver 422 for received transmissions (e.g., packets 210 and 220) for STRM field content (e.g., which may include feature data) and to program the demultiplexer (DEMUX) 424 in response thereto. In one example, the stream selector 423 is adapted to generate a destination indication in response to an identification field (the stream selector 423 is optionally adapted to receive the identification field).

[0062] The switch 427 includes a switch local output and a switch system output. The switch 427 is coupled to an output of the receiver 422 (or optionally coupled to an input of the receiver 422) and is adapted to generate a transmission (e.g., an output signal) at a switch local output (e.g., a first output of the switch) in response to an indication of the stream selector 423 output and the input data, and is adapted to generate a transmission at a switch system output in response to the input data. The switch local output is adapted to be coupled to a first destination node, and the switch system output is adapted to be coupled to a second destination node. For example, the switch 427 is adapted to generate an output packet adapted to be transmitted at a switch local output (e.g., local exporter 425) in response to the identification field, e.g., when the identification field indicates that the packet should be exported to the local display 404. In one example, the switch 427 is adapted to route the input data to a switch system output (e.g., stream forwarder 426) in response to a destination indication, for example when the destination indication at the output of the stream selector 423 indicates that the packet should be forwarded to another display (e.g., the packet should not be exported to the local display 404). In another example, the switch 427 forwards (e.g., transmits) all input data received by the stream disaggregator 420, which input data is combined from the receiver inputs 422 (this combining may include combining the input data via the receiver 422 itself and the receiver 422 outputs), such that the transmissions at the switch system outputs are generated by the switch 427 in response to the input data (e.g., regardless of the content of the stream fields 214 and 224).

[0063] The demultiplexer 424 includes a first output adapted to be coupled to a first destination node, and the demultiplexer 424 includes a second output adapted to be coupled to a second destination node. For example, the demultiplexer 424 includes a first output adapted to be coupled to a local display 404 via a local exporter 425. The first destination node is a local (e.g., local to the stream disaggregator 420 instance) node address that may be associated with at least one display node address. In this example, the demultiplexer 424 includes a second output adapted to be coupled to a local display 406 (for example) via a stream forwarder 426, a cable 412, and a stream disaggregator 430. The second destination node is a non-local node address that may be associated with a display node address that indicates a node address other than the node address associated with the first destination node. The node addresses may be logical addresses of various display nodes, while the stream field content identifies a particular video stream (e.g., may be selectively received by one or more displays having different logical addresses). The stream selector may be dynamically programmed (e.g., in response to a received control packet) to direct a selected video stream to a local display associated with the stream selector. The stream forwarder 426 is coupled to the switch system output, the stream forwarder adapted to transmit according to the system protocol.

[0064] In one example, the demultiplexer 424 is adapted to couple (e.g., by switching) an incoming packet to a first output of the switch and a second output of the switch in response to a destination indication. In one example, the demultiplexer 424 is adapted to generate a packet at a selected one of at least the first output of the switch and the second output of the switch in response to an identification field. In one example, the demultiplexer 424 is adapted to generate a packet destination indication in response to an identification field of the incoming packet.

[0065] The local link controller is a local controller coupled to a switch local output, which is adapted to transmit to a display. The local link controller 421 is adapted to monitor transmissions (e.g., packets 210 and 220) received by the receiver 422 for commands (e.g., function data). The local link controller 421 is adapted to control the transmission of packets from the switch local output according to a local protocol (e.g., a protocol different from the system protocol).

[0066] The local exporter 425 is coupled to a first output of the demultiplexer 424, where the local exporter 425 includes an exporter output adapted to be coupled to a display. For example, a first output of the demultiplexer 424 is coupled to an input of the local exporter 425. An exporter output of the local exporter 425 may be coupled (e.g., connected) to the local display 404.

[0067] The output of the local exporter 425 includes a local protocol. In one example, the local protocol is a display port protocol, such as the embedded Display port (eDP) standard of the Video Electronics Association of America (VESA). Thus, input data may be received by the receiver 422 according to a system protocol (e.g., FDP) that is different from at least one of the local protocols. Other display port protocols that may be supported as local protocols include DisplayPort (DP), Open Liquid Crystal Display Interface (OpenLDI), and Mobile Industry Processor Interface (MIPI) Display Serial Interface (DSI), and Camera Serial Interface (CSI). A first local protocol (e.g., 405) of a first display (e.g., 404) may be a different protocol than a second local protocol (e.g., 407) of a second display (e.g., 406).

[0068] The stream disaggregator 420 may be programmed to operate according to a protocol associated with a particular display locally coupled to the local exporter 425. For example, the multi-stream generator 410 may configure the stream disaggregator 420 by sending a start command to the local link controller 421 that includes an indication of the selected protocol. The indication of the selected protocol may be included, for example, within the stream payload 212. In an example system, a first stream disaggregator (e.g., 420) is adapted to select a first local protocol (e.g., 405) and a second stream disaggregator (e.g., 430) is adapted to select a second local protocol that is a different protocol than the first local protocol.

[0069] In an example system with two displays, a first cable (e.g., 411) is coupled between an output of the multi-stream generator 410 and an input of the first stream disaggregator 420, and a second cable (e.g., 412) is coupled between a second output of the first stream disaggregator 420 and an input of the second stream disaggregator 430. In an example system with two displays, received packets (e.g., encoded packets) of the first video stream are sent via the first cable (e.g., via a first switch local output) to the first display, and received packets (e.g., encoded packets) of the second video stream are sent via the first cable and the second cable (e.g., via a first switch system output and a second switch local output) to the second display.

[0070] In an example with at least two displays, the stream disaggregator 430 may include a second receiver having a second receiver input having a second receiver output adapted to receive second input data from the first switch local output; a second selector having a second selector output, the second selector coupled to the second receiver, the second selector configured to generate a second destination indication at the second selector output; and a second switch having a second switch local output and a second switch system output, the second switch coupled to the second receiver, the second switch adapted to generate a transmission at the second switch local output in response to an indication of the second selector output and the second input data, and the second switch adapted to generate a transmission at the second switch system output in response to the second input data.

[0071] In an example system having at least two displays, the stream disaggregator 430 further includes a second local controller coupled to a second switch local output adapted to transmit to the second display, and the second local exporter arranged to transmit data to the second display in response to a start command of a packet including a second destination indication indicating the second display.

[0072] In another example system with at least two displays, a head unit is adapted to generate at least two video streams at an output of the head unit, a multi-stream generator is coupled to the output of the head unit and adapted to generate encoded packets containing information from the at least two video streams and send the encoded packets to a source output, the input data including packets from one of the at least two video streams. The encoded packets may be encoded by an encoder such as FDP encoders 372, 374, 376, and 378, and the encoded packets may be decoded by a receiver (e.g., receiver 422 of a downstream stream disaggregator).

[0073] In an example system with at least two displays, the system includes a head unit adapted to generate at least two video streams; a multi-stream generator coupled to the head unit, the multi-stream generator adapted to generate encoded packets including an identification field and including information from the at least two video streams and combine the encoded packets to an output of the multi-stream generator; and a first stream disaggregator having a first stream input coupled to the output of the multi-stream generator, the first stream disaggregator having a first output adapted to combine the received encoded packets to the first display according to a first local protocol in response to the identification field of the received encoded packets indicating a node address of the first display; a first stream disaggregator having a second output adapted to forward received encoded packets in response to the identification field of the received encoded packets indicating a node address other than the first display node address; and a second stream disaggregator having a second stream coupled to the second output of the first stream disaggregator, the second stream disaggregator having a first output adapted to couple received encoded packets to the second display according to a second local protocol in response to the identification field of the received encoded packets indicating the second display node, and the second stream disaggregator having a second output adapted to forward received encoded packets in response to the identification field of the received encoded packets indicating a node address other than the second display node address.An example system may further include a third stream disaggregator having a third stream input coupled to the second output of the second stream disaggregator, the third stream disaggregator having a first output adapted to couple the received encoded packet to a third display in response to the identification field of the received encoded packet indicating the third display node address, and the third stream disaggregator having a second output adapted to forward the received encoded packet in response to the identification field of the received encoded packet indicating a node address other than the third display node address. The example system may further include a first cable coupled between an output of the multi-stream generator and the first stream input, and a second cable coupled between a second output of the first stream disaggregator and the second stream disaggregator, where the encoded packets of the first video stream are transmitted via the first cable to the first display and the encoded packets of the second video stream are transmitted via the first cable and the second cable to the second display. In the example system, the first local protocol may be a different protocol than the second local protocol.

[0074] An example method for networking a multi-display system may include operations such as sending a first transmission to a first display, including information from the received encoded packet, in response to the identification field of the received encoded packet indicating a node address of the first display; forwarding a second transmission including information from the received encoded packet in response to the identification field of the received encoded packet indicating a node address other than the first display node address; sending a third transmission to a second display, including information from the received encoded packet, in response to the identification field of the received encoded packet indicating the second display; and forwarding a fourth transmission including information from the received encoded packet in response to the identification field of the received encoded packet indicating a node address other than the second display node address. When the received encoded packet is a first encoded packet, the example method may further include generating a first encoded packet in response to information received from the first video stream and generating a second encoded packet in response to information received from the second video stream, transmitting the first encoded packet of the first video stream to a first display via a first cable, and transmitting the second encoded packet of the second video stream to a second display via the first cable and the second cable. The example method may further include generating the first video stream in response to sensors of the vehicle including the first display and the second display.

[0075] In an example system with three displays, a first cable (e.g., 411) is coupled between an output of the multi-stream generator 410 and an input of the first stream disaggregator 420, a second cable (e.g., 412) is coupled between a second output of the first stream disaggregator 420 and an input of the second stream disaggregator 430, and a third cable (e.g., 413) is coupled between a second output of the second stream disaggregator 430 and an input of the third stream disaggregator 440. In an example system with three displays, received encoded packets of a first video stream are transmitted via a first cable (e.g., via a first switch local output) to a first display, received encoded packets of a second video stream are transmitted via the first cable and a second cable (e.g., via a first switch system output and a second switch local output) to a second display, and received encoded packets of a third video stream are transmitted via the first cable, the second cable, and a third cable (e.g., via the first switch system output, the second switch system output, and a third switch local output) to a third display.

[0076] In accordance with examples described herein, additional displays and video streams can be added to multiple display units without increasing the number of cables coupled (e.g., physically coupled) to the head unit 401 and / or multi-stream generator 410 (for example).

[0077] 5 is a block diagram of an exemplary system including at least one bus unit adapted to generate and transfer a system wake-up signal between serially chained bus units. For example, system 500 is an exemplary system including head unit 401 (e.g., coupled to sensor 402), first bus unit 510 (e.g., locally coupled to head unit 401 via local port 561 and cable 560), second bus unit 520 (e.g., locally coupled to touch display 572 via local port 562 and cable 405), third bus unit 530 (e.g., locally coupled to touch display 573 via local port 563 and cable 407), and fourth bus unit 540 (e.g., locally coupled to touch display 574 via local port 564 and cable 409). Bus units 510, 520, 530, and 540 may be adapted to transmit data bidirectionally (e.g., at 165 megabits per second upstream or 13 gigabits per second downstream). Bus units 520, 530, and 540 may be serializers and / or deserializers (e.g., SERDES) and / or disaggregators (such as 420, 430, and 440, respectively).

[0078] In an example wake-up sequence generally described hereafter, the second bus unit 520 may be configured from a power-saving mode to an active mode (e.g., awakened) by a local wake-up signal generated in response to a wake-up event detected at the touch display 572. In response to the local wake-up signal, the second bus unit 520 may generate and transmit a system wake-up signal to the first bus unit 510 (e.g., so that the system wake-up signal is transmitted in an upstream direction and, in response, the first bus unit 510 is awakened). Similarly, the second bus unit 520 may generate and transmit a system wake-up signal to the third bus unit 530 (e.g., so that the system wake-up signal is transmitted in a downstream direction and, in response, the third bus unit 5 is awakened). In this example, the third bus unit 530 may generate a subsequent wake-up signal in response to receiving the system wake-up signal and transmit the wake-up signal to the fourth bus unit 540 (e.g., so that a system wake-up signal is transmitted downstream and, in response, the third bus unit 530 is awakened). Other wake-up sequences are described hereinafter (e.g., in connection with FIGS. 8, 9, and 10).

[0079] In the first example system, system 500 includes a first bus unit (FBU) 510 having a first system port (e.g., downstream D-port 591), an FBU local port (e.g., local L-port 561), an FBU wakeup input, an FBU transceiver 512, an FBU controller 514, and an FBU energy detector 516. The FBU transceiver 512 is coupled to the FBU first system port, the FBU local port, and the FBU wakeup input.

[0080] The FBU first system port (e.g., 591) is adapted to receive the FBU first system input signal. The FBU local port (e.g., 561) is adapted to receive the FBU local input signal. The FBU transceiver 512 is configured to transmit data of the FBU first system input signal to the FBU local port (e.g., 561) in an FBU first mode (e.g., active mode). The FBU transceiver 512 is configured to save power in an FBU second mode. The FBU transceiver 512 is configured to enter the FBU first mode in response to an FBU local wakeup signal. The FBU transceiver 512 is configured to transmit an FBU system wakeup signal at one of the FBU first system port (e.g., 591) and the FBU local port (e.g., 561) in response to the FBU local wakeup signal.

[0081] The FBU controller 514 has an FBU energy detect input and an FBU wakeup output coupled to the FBU wakeup input. The FBU controller 514 is configured to generate an FBU local wakeup signal at the FBU wakeup output in response to the FBU energy detect signal.

[0082] FBU energy detector 516 has an FBU energy detect output coupled to the FBU energy detect input. FBU energy detector 516 is coupled to the FBU first system port (e.g., via bus 551) and the FBU local port (e.g., via node 561a). FBU energy detector 516 is configured to generate an FBU energy detect signal at the FBU energy detect output in response to FBU detection of energy in one of the FBU first system input signal (e.g., via node 561a) and the FBU local input signal received by FBU transceiver 512 in the FBU second mode.

[0083] In the first exemplary system, system 500 further includes a second bus unit (SBU) 520 having an SBU first system port (e.g., upstream U-port 582). The SBU first system port is coupled to an FBU first system port (e.g., downstream D-port 591). The SBU first system port (e.g., 582) is adapted to receive an FBU system wakeup signal, and the FBU first system port (e.g., 591) is adapted to receive an SBU system wakeup signal (e.g., when transmitted by SBU 520 via the SBU first system port).

[0084] SBU 520 may further include an SBU second system port (e.g., downstream D-port 592), an SBU local port (e.g., local L-port 562), an SBU wakeup input, an SBU transceiver 522, an SBU controller 524, and an SBU energy detector 526. SBU transceiver 522 is coupled to the SBU first system port, the SBU second system port, the SBU local port, and the SBU wakeup input.

[0085] The SBU first system port (e.g., 582) is adapted to receive an SBU first system input signal, the SBU second system port (e.g., 592) is adapted to receive an SBU second system input signal, and the SBU local port (e.g., 562) is adapted to receive an SBU local input signal. The SBU transceiver 522 is configured to transmit data of the SBU first system input signal to the SBU second system port (e.g., 592) in an SBU first mode (e.g., active mode), and the SBU transceiver 522 is configured to save power in an SBU second mode (e.g., power save mode). The SBU transceiver 522 is configured to enter the SBU first mode in response to an SBU local wakeup signal. The SBU transceiver 522 is configured to transmit an SBU system wakeup signal at one of the SBU first system port and the SBU second system port in response to the SBU local wakeup signal.

[0086] In general, SBU 520 may detect a wake-up signal on any of the SBU first system port (e.g., 582), the SBU second system port (e.g., 592), and the SBU local port (e.g., 562). SBU 520 is configured to generate (in response to the detected wake-up signal) a subsequent wake-up signal to be transmitted to the port that received the detected wake-up signal. In a first scenario, a wake-up signal is detected via the SBU local port (e.g., 562), and in response, SBU transceiver 522 transmits a system wake-up signal via the SBU first system port (e.g., 582) and via the SBU second system port (e.g., 592). In a second scenario, a wake-up signal is detected via the SBU first system port (e.g., 582), and in response, the SBU transceiver 522 transmits a system wake-up signal via the SBU second system port (e.g., 592) and transmits a local wake-up signal via the SBU local port (e.g., 562). In a third scenario, a wake-up signal is detected via the SBU second system port (e.g., 592), and in response, the SBU transceiver 522 transmits a system wake-up signal via the SBU first system port (e.g., 582) and transmits a local wake-up signal via the SBU local port (e.g., 562). In response to the SBU 522 receiving a system wake-up signal from either the FBU 510 or the third bus unit 530, transmitting a local wake-up signal to the touch display 572 may signal the touch display to convert from a power save mode to an active mode.

[0087] The SBU controller 524 has an SBU energy detect input and an SBU wakeup output coupled to the SBU wakeup input and is configured to generate an SBU local wakeup signal at the SBU wakeup output in response to the SBU energy detect signal.

[0088] SBU energy detector 526 has an SBU energy detect output coupled to the SBU energy detect input. SBU energy detector 526 is coupled to the SBU first system port (e.g., 582), the SBU second system port (e.g., 592), and the SBU local port (e.g., 562). SBU energy detector 526 is configured to generate an SBU energy detect signal at the SBU energy detect output in response to SBU detection of energy in one of the SBU first system input signal (e.g., via node 582a), the SBU second system input signal (e.g., via bus 552), and the SBU local input signal (e.g., via node 562a) received by SBU transceiver 522 in the SBU second mode.

[0089] In the first exemplary system, system 500 further includes a third bus unit (TBU) 530 having a TBU first system port (e.g., upstream U-port 583), an optional TBU second system port (e.g., downstream D-port 593), a TBU local port (e.g., local L-port 563), a TBU wakeup input, a TBU transceiver 532, a TBU controller 534, and a TBU energy detector 536. The TBU first system port (e.g., 583) is coupled to the SBU second system port (e.g., 592). The TBU transceiver 532 is coupled to the TBU first system port, the optional TBU second system port, the TBU local port, and the TBU wakeup input.

[0090] The TBU first system port (e.g., 583) is adapted to receive a TBU first system input signal, the optional TBU second system port (e.g., 593) may be adapted to receive a TBU second system input signal, and the TBU local port (e.g., 563) is adapted to receive a TBU local input signal. The TBU transceiver 532 is configured to transmit data of the TBU first system input signal to one of the TBU local port (e.g., 563) and the TBU second system port (e.g., 593) in the TBU first mode (e.g., active mode), and the TBU transceiver 532 is configured to save power in the TBU second mode (e.g., power save mode). The TBU transceiver 532 is configured to enter the TBU first mode in response to a TBU local wakeup signal. The TBU transceiver 532 is configured to transmit a TBU system wakeup signal at one of the TBU first system port and the TBU local port in response to the TBU local wakeup signal. The SBU second system port (e.g., 592) is adapted to receive the TBU system wakeup signal (e.g., in response to a TBU system wakeup signal being transmitted by the TBU 530 via the TBU first system port).

[0091] In general, TBU 530 may detect a wake-up signal on any of the first system port (e.g., 583), the TBU second system port (e.g., 593), and the TBU local port (e.g., 563). TBU 530 is configured to generate (in response to the detected wake-up signal) a subsequent wake-up signal to be transmitted to the port on which the detected wake-up signal was received. In a first scenario, a wake-up signal is detected via the TBU local port (e.g., 563), and in response, TBU transceiver 532 transmits a system wake-up signal via the TBU first system port (e.g., 583) and via the TBU second system port (e.g., 593). In a second scenario, a wake-up signal is detected via the TBU first system port (e.g., 583), and in response, the TBU transceiver 532 transmits a system wake-up signal via the TBU second system port (e.g., 593) and transmits a local wake-up signal via the TBU local port (e.g., 563). In a third scenario, a wake-up signal is detected via the TBU second system port (e.g., 593), and in response, the TBU transceiver 532 transmits a system wake-up signal via the TBU first system port (e.g., 583) and transmits a local wake-up signal via the TBU local port (e.g., 563). In response to the TBU 532 receiving a system wake-up signal from either the SBU 510 or the third bus unit 530, transmitting a local wake-up signal to the touch display 573 may signal (e.g., command) the touch display to convert from a power-save mode to an active mode.

[0092] The TBU controller 534 has a TBU energy detect input and a TBU wakeup output coupled to the TBU wakeup input. The TBU controller 534 is configured to generate a TBU wakeup signal at the TBU wakeup output in response to the TBU energy detect signal.

[0093] The TBU energy detector 536 has a TBU energy detect output coupled to the TBU energy detect input. The TBU energy detector 536 is coupled to the TBU first system port (e.g., 583), the TBU second system port (e.g., 593), and the TBU local port (e.g., 563). The TBU energy detector 536 is configured to generate a TBU energy detect signal at the TBU energy detect output in response to TBU detection of energy in one of the TBU first system input signal (e.g., via node 583a), the optional TBU second system input signal (e.g., via bus 553), and the TBU local input signal (e.g., via node 563a) received by the TBU transceiver 532 in the TBU second mode.

[0094] In the first exemplary system, the system 500 may further include additional (e.g., optional) bus units to extend the system bus of the serial chain. For example, the fourth bus unit 540 has a first system port (e.g., upstream U-port 584), a second system port (e.g., downstream D-port 594), a local port (e.g., local L-port 564), a wake-up input, a transceiver 542, a controller 544, and an energy detector 546. The first system port (e.g., 584) is coupled to the TBU second system port (e.g., 593).

[0095] The first system port (e.g., 584) is adapted to receive a first system input signal, the optional second system port (e.g., 594) may be adapted to receive a second system input signal, and the local port (e.g., 564) is adapted to receive a local input signal. The transceiver 542 is configured to transmit data of the first system input signal to one of the local port (e.g., 564) and the second system port (e.g., 594) in a first mode (e.g., an active mode), and the transceiver 542 is configured to save power in a second mode (e.g., a power save mode). The transceiver 542 is configured to enter the first mode in response to a local wake-up signal. The transceiver 542 is configured to transmit a system wake-up signal at one of the first system port and the local port in response to the local wake-up signal. The TBU second system port (e.g., 593) is adapted to receive a fourth bus unit generated system wake-up signal (e.g., in response to a fourth bus unit system wake-up signal being transmitted by the fourth bus unit 540 via the fourth bus unit's first system port).

[0096] The controller 544 has an energy detect input and a wakeup output, the wakeup output coupled to the wakeup input, and is configured to generate a local wakeup signal at the wakeup output in response to the energy detect signal.

[0097] The energy detector 546 has an energy detect output coupled to the energy detect input. The energy detector 546 is coupled to the first system port (e.g., 584), the second system port (e.g., 594), and the local port (e.g., 564). The energy detector 546 is configured to generate an energy detect signal at the energy detect output in response to detecting energy in one of the first system input signal (e.g., via node 584a), the optional second system input signal (e.g., via bus 554), and the local input signal (e.g., via node 564a) received by the transceiver 542 in the second mode.

[0098] In the first example system, system 500 further includes a user interface (UI) device, such as one of touch displays 572, 573, and 574. Touch display 572 is coupled to switch 527 (e.g., similar to switch 427) of transceiver 522 of SBU 520 via cable 405 and local port 562, touch display 573 is coupled to switch 537 (e.g., similar to switch 437) of transceiver 532 of TBU 530 via cable 407 and local port 563, and touch display 574 is coupled to switch 547 (e.g., similar to switch 447) of transceiver 542 of fourth bus unit 540 via cable 409 and local port 564.

[0099] With respect to the FBU 510, a UI device (e.g., sensor 402 and head unit 401) includes a UI port (e.g., 560) that is coupled to an FBU local port (561), which is adapted to receive user input (such as user touch, user voice, user manipulation, proximity detection, and physical or electronic indications). The FBU 510 is configured to generate a user wake-up signal at the UI port in response to the user input. The FBU 510 is configured to generate an SBU system wake-up signal in response to the user wake-up signal. The SBU 520 is configured to generate an SBU local wake-up signal in response to the FBU system wake-up signal.

[0100] With respect to SBU 520, a UI device (e.g., touch display 572) includes a UI port (e.g., 405) coupled to an SBU local port (562), the UI device adapted to receive user input. SBU 520 is configured to generate a user wakeup signal at the UI port in response to the user input. SBU 520 is configured to generate an SBU system wakeup signal in response to the user wakeup signal. FBU 510 is configured to generate an FBU local wakeup signal in response to the SBU system wakeup signal, and TBU 530 is configured to generate an FBU local wakeup signal in response to the SBU system wakeup signal.

[0101] With respect to the TBU 530, a UI device (e.g., touch display 573) includes a UI port (e.g., 407) coupled to a TBU local port (563), the UI device adapted to receive user input. The TBU 530 is configured to generate a user wake-up signal at the UI port in response to the user input. The TBU 530 is configured to generate a TBU system wake-up signal in response to the user wake-up signal. The SBU 520 is configured to generate an SBU local wake-up signal in response to the TBU system wake-up signal, and the fourth bus unit 540 is configured to generate a fourth bus unit local wake-up signal in response to the TBU system wake-up signal.

[0102] With respect to the fourth bus unit 540, a UI device (e.g., touch display 574) includes a UI port (e.g., 409) coupled to the fourth bus unit's local port (564), the UI device adapted to receive user input. The fourth bus unit 540 is configured to generate a user wake-up signal at the UI port in response to the user input. The fourth bus unit 540 is configured to generate a fourth bus unit system wake-up signal in response to the user wake-up signal. The TBU 530 is configured to generate a TBU local wake-up signal in response to the fourth bus unit system wake-up signal, and additional bus units in any serial chain are configured to generate their respective unit local wake-up signals in response to the bass unit system wake-up signal of an adjacent serial chain.

[0103] In the second example system, the system 500 includes a power management system 508. The power management system 508 includes power managers such as a PMIC (power manager integrated circuit) 518 coupled to the FBU 510, a PMIC 528 coupled to the SBU 520, a PMIC 538 coupled to the TBU 520, and a PMIC 548 coupled to the fourth bus unit 540. The PMIC 518, PMIC 528, PMIC 538, and PMIC 548 may be included on a common substrate or may be included on a substrate that includes the bus unit to which each PMIC and / or combinations thereof are coupled. For example, power to operate the power manager and control of the energy detection circuitry may be provided (e.g., coupled) via a VDDKA (first power rail keep alive) power signal (which reduces power consumption, e.g., in a power saving mode).

[0104] In the second example system, the system 500 includes a circuit (such as the SBU 520) that includes a transceiver (eg, 522), a controller (eg, 524), and an energy detector (eg, 526).

[0105] The transceiver (e.g., 522) has a first system port (e.g., a first selected one of 582 and 592), a second system port (e.g., a second selected one of 582 and 592, which is different from the first selected one of 582 and 592), a local port (e.g., 562), and a wakeup input. The first system port is adapted to receive a first system input signal, the second system port is adapted to receive a second system input signal, and the local port is adapted to receive a local input signal. The transceiver is configured to transmit data of the first system input signal to the second system port in a first mode, the transceiver is configured to save power in a second mode, the transceiver is configured to enter the first mode in response to a local wakeup signal, and the transceiver is configured to transmit a system wakeup signal at the second system port in response to the local wakeup signal.

[0106] A controller (e.g., 524) has an energy detect input and a wakeup output, the wakeup output coupled to the wakeup input, and is configured to generate a local wakeup signal at the wakeup output in response to the energy detect signal.

[0107] An energy detector (e.g., 526) has an energy detect output coupled to the energy detect input. The energy detector is coupled to the first system port and the local port. The energy detector is configured to generate an energy detect signal at the energy detect output in response to detecting energy in one of the first system input signal and the local input signal received by the transceiver in the second mode.

[0108] In one example, the transceiver is further configured to transmit data of the second system input signal to the first system port in the first mode. In this example, the system wake-up signal may include a wake-up pattern.

[0109] In another example, the transceiver is further configured, in the second mode, to transmit a system wakeup signal at the first system port in response to the local wakeup signal.

[0110] In yet another example, the energy detector is configured to detect energy in one of the first system input signal and the local input signal. In this example, the energy detector may be coupled to the second system port, and the energy detector may be configured to detect energy in the second system input signal. In this example, the energy detector is configured to generate an energy detect signal at an energy detect output in response to detecting energy in the second system input signal received by the transceiver in the second mode.

[0111] In a further example, the controller is further coupled to the first system port and the local port. The controller is further configured to detect a wake-up pattern in one of the first system input signal and the local input signal in response to the energy detect signal. In this example, the controller may further include a data valid output, the controller configured to generate a data valid signal at the data valid output in response to detecting the wake-up pattern in one of the first system input signal and the local input signal. In this example, the energy detector may further include a data valid input and an enable power output, the data valid input coupled to the data valid output, the energy detector further configured to generate an enable power signal at the enable power output. In this example, the circuit may further include a power manager, the power manager including an enable power input and a power supply output, the enable power input coupled to the enable power output, the power manager configured to generate a power signal at the power supply output in response to the enable power signal. In this example, the controller further includes a power supply input, the power supply input coupled to the power supply output, the controller further configured to generate a local wake-up signal in response to the power signal. In an example system, the power manager circuitry may further include a logic enable output, and the controller may further include a logic enable input, the logic enable input coupled to the logic enable output, the power manager may further be configured to generate a logic enable signal at the logic enable output in response to the power signal, and the controller may further be configured to generate a local wake-up signal in response to the logic enable signal.

[0112] 6 is a flow chart of an example method of wake-up signal issuance of the example system of FIG. 5. The example method 600 may include various techniques described hereinafter. In various implementations, the described operations do not necessarily have to be performed in the order described. In the example method 600, the method may begin at 605.

[0113] At 605, the method may include receiving a first wake-up signal by a first port of a first bus unit (FBU). For example, the first wake-up signal may be generated by head unit 401 in response to sensor 502. The first wake-up signal may be received by FBU 510 at local port 561. The method may continue at 610.

[0114] At 610, the method may include applying power to a second port of the FBU in response to the first wake-up signal. For example, a power management circuit element, such as the PMIC 518, may couple operating power to a transmitter (e.g., of the transceiver 512) so that the transmitter may exit a power saving mode and enter an active mode (e.g., where a signal may be transmitted). In one example, the power may be coupled by energizing a power supply. In another example, a system clock may be started (e.g., issued) so that additional power is drawn in response to switching of active CMOS circuit elements being toggled by the started system clock. In some implementations, the entire bus unit may be placed in an active mode by applying power to active circuit elements of all bus units in response to the received wake-up signal. The method may continue at 615.

[0115] At 615, the method may include transmitting a second wake-up signal by a second port of the FBU in response to the first wake-up signal. For example, a transmitter portion of the transceiver 512 may transmit the second wake-up signal from a second port (e.g., the first system port 591). The method may continue at 620.

[0116] At 620, the method may include receiving a second wake-up signal by a first port of a second bus unit (SBU). For example, the second wake-up signal may be generated by FBU 510 in response to the first wake-up signal. The second wake-up signal may be received by SBU 520 at first system port 582. The method may continue at 625.

[0117] At 625, the method may include applying power to a second port of the SBU in response to the second wake-up signal. For example, power management circuitry, such as the PMIC 528, may couple operating power to the transmitter (e.g., the transceiver 522) such that the transmitter may exit a power save mode and enter an active mode (e.g., where a signal may be sent). The method may continue at 630.

[0118] At 630, the method may include transmitting a third wake-up signal by a second port of the SBU in response to the second wake-up signal. For example, the transmitter portion of the transceiver 522 may transmit the third wake-up signal from a second port (e.g., second system port 592). The transmitter portion of the transceiver 522 may optionally send a local wake-up signal from a third port (e.g., 562) to a locally coupled device (e.g., touch display 572) in response to the second wake-up signal. The method may continue at 635.

[0119] At 635, the method may include receiving a third wake-up signal by a first port of a third bus unit (TBU). For example, the third wake-up signal may be generated by SBU 520 in response to the second wake-up signal. The third wake-up signal may be received by TBU 530 at first system port 582. The method may continue at 625.

[0120] At 640, the method may include applying power to the TBU in response to the third wake-up signal. For example, power management circuitry, such as PMIC 538, may couple operating power to TBU 530 such that TBU 530 may exit a power save mode and enter an active mode (e.g., where signals may be actively received and transmitted). Thus, in the system 500 described herein, local wake-up events may be issued across and through the serial chain of bus units.

[0121] 7 is a flow chart of an example method of wake-up signal detection and wake-up signal processing for the example system of FIG. 5. The example method 700 may include various techniques described hereinafter. In various implementations, the described operations do not necessarily have to be performed in the order described. In the example method 700, the method may begin at 705.

[0122] At 705, the method may include monitoring, by an energy detector (e.g., 526), ​​a wake-up mode signal. For example, the wake-up mode signal may be a VDDKA signal that may provide operating power to the energy detector of the bus unit. The method may continue at 710.

[0123] If the wake-up mode signal is asserted at 710 , then the method continues at 715 , otherwise the method continues at 705 .

[0124] At 715, the method may include monitoring the incoming signal for signal energy by an energy detector (e.g., 526). For example, the energy detector of the bus unit may compare the field strength, current, and / or voltage levels carried by the conductors against a threshold value to detect quantized changes in the incoming signal. The signal net (e.g., signal line) may be a dedicated wake-up signal conductor or may be used for other purposes (e.g., a signal lane for receiving video stream information from an upstream source) while the bus unit is operating in the active mode. The method may continue at 720.

[0125] If signal energy is detected at 720 , then the method continues at 725 , otherwise the method continues at 705 .

[0126] At 725, the method may include asserting an enable power signal by an energy detector (e.g., 526) in response to detecting the signal energy. The method continues at 730.

[0127] At 730, the method may include asserting, by an energy detector (e.g., 526), ​​an energy detect signal in response to detecting the signal energy. The method continues at 735.

[0128] At 735, the method may include applying power by a power management interface controller (e.g., 528) to a controller (e.g., 524) of the bus unit in response to the asserted enable power signal. The method continues at 740.

[0129] At 740, the method may include asserting, by a power management interface controller (e.g., 528), a logic enable signal in response to the enable power signal. For example, the logic enable signal may be asserted after a period of time following application of power to allow logic circuitry of the controller to stabilize. The method continues at 745.

[0130] At 745, the method may include determining, by a controller (e.g., 524), a start time of a valid detection period. For example, the controller may determine a start time of a valid detection period (e.g., start a timer) in response to the logic enable signal. During this valid detection period, an input signal (e.g., a potential wake-up signal) is evaluated for valid data (e.g., a wake-up pattern). The method continues at 750.

[0131] At 750, the method may include evaluating, by a controller (e.g., 524) of the bus unit, a received signal of the input signal for valid data. For example, the input signal may be evaluated to determine the presence of a wake-up pattern. The valid data may also include a wake-up code configured to identify the bus unit from which the wake-up signal was received in the input signal. The wake-up pattern may be encoded to reduce entropy (e.g., to reduce false positives due to injected noise). The method continues at 755.

[0132] At 755 , the method continues at 780 if valid data is detected, otherwise the method continues at 760 .

[0133] At 760, the method continues at 765 if the valid detection period has expired (eg, the valid detection period has passed), otherwise the method continues at 750.

[0134] At 765, the method may include indicating, by a controller of the bus unit (eg, 524), that no valid data was detected. The method continues at 770.

[0135] At 770, the method may include deasserting, by an energy detector (e.g., 526), ​​an enable power signal in response to an indication that valid data was not detected. For example, the enable power signal may be deasserted by negating an active low signal (e.g., valid data), which, when active low, indicates that valid data was detected. The method continues at 775.

[0136] At 775, the method may include removing power from the bus unit's controller (e.g., 524) by a power management interface controller (e.g., 528) in response to the enable power signal being deasserted. The method continues at 705.

[0137] At 780, the method may include a bus unit (e.g., bus unit 520, a first bus unit including energy detector 526 and controller 524) transmitting a wake-up signal (e.g., a second wake-up signal) to another bus unit (e.g., a second bus unit such as bus unit 510 and / or 530). For example, the first bus unit may send a second wake-up signal to a second bus unit, the second wake-up signal being encoded with an identifier of the first bus unit, the second bus unit being not the bus unit to which the first wake-up signal was sent. The wake-up signal may include a repeating pattern such that the wake-up signal may be transmitted (e.g., repeatedly transmitted) over a valid detection period. The length (e.g., duration) of the valid detection period may be selected for each bus unit. In one example, the wake pattern includes three start bits "101", four address bits "0010" (which indicate bus unit 520), and an even parity bit "1", so that the transmitted wake pattern is a repeatable pattern of eight bits "10100101". When the received pattern does not include the correct parity bits and does not include the start bits "101", the data valid signal is deasserted (e.g., set high) by controller 524 to indicate that the received wake pattern is not valid, and as a result, energy detector 526 does not assert the enable power signal in response to the invalid wake pattern.

[0138] 8 is a block diagram of a first example wake-up signal processing scenario in an example system. In this example, system 800 includes serially concatenated bus units such as 810, 820, 830, and 840. The bus units may be deserializers (which may include both serialization and deserialization circuits themselves) and / or disaggregators (as described above in connection with FIG. 4).

[0139] The FBU 810 may be similar to the multi-stream generator 410 and / or the FBU 510. The FBU 810 may be locally coupled to various devices (e.g., the sensor 402 and the head unit 401) and may generate a local wake-up signal in response to input generated by any coupled sensor. The FBU 810 is upstream of the SBU 820 (e.g., with respect to the majority direction of video stream flow in the main channel of the system bus). The FBU 810 is coupled to the SBU 820 via a cable 801. The cable 801 (and each of the cables 802, 803, and 804) may be a cable harness that includes conductors (e.g., twisted pair, coaxial, or optical fiber) for transmitting and / or receiving the wake-up signal. In some examples, in an active mode, a conductor reserved as a "lane" for video streaming may be used to transmit a wake-up signal to an adjacent bus unit in a power saving mode.

[0140] The FBU 810 is coupled to a second bus unit (SBU) 820 via cable 801. The SBU 820 is locally coupled to a touch display 826 (which may be similar to the touch display 572) via cable 824, where the SBU 820 is configured to disaggregate video in active mode (by switch 822) and send the disaggregated stream to the touch display 826. The SBU 820 is coupled to a third bus unit (TBU) 830 via cable 802. The TBU 830 is locally coupled to a touch display 836 (which may be similar to the touch display 573) via cable 834, where the TBU 830 is configured to disaggregate video in active mode (by switch 832) and send the disaggregated stream to the touch display 836. The TBU 830 is coupled to a fourth bus unit 840 via cable 803. A fourth bus unit 840 is locally coupled to a touch display 846 (which may be similar to touch display 574) via cable 844, and the fourth bus unit 840 is configured to disaggregate video in active mode (via switch 842) and send the disaggregated stream to the touch display 846. The fourth bus unit 840 may be coupled to an adjacent (e.g., downstream) bus unit via cable 804 (even more downstream bus units may be chained in series along the system bus, with each additional downstream unit locally coupled to similar circuitry).

[0141] In a first example scenario, a first bus unit (e.g., FBU 810) is configured to generate (e.g., transmit) a system wake-up signal 850 at a first time (e.g., time T0) in response to a user wake-up signal (e.g., generated by the sensor 402 and head unit 401). The system wake-up signal 850 is generated at a first output (e.g., cable 801). A second bus unit (e.g., SBU 820) is configured to generate (e.g., transmit) a system wake-up signal 851 at a second time (e.g., time T1 following the first time) in response to the system wake-up signal 850. The system wake-up signal 851 is generated at a second output (e.g., cable 802). A third bus unit (e.g., TBU 830) is configured to generate (e.g., transmit) a system wake-up signal 852 at a third time (e.g., time T2 following the second time) in response to the system wake-up signal 851. The system wake-up signal 852 is generated at a third output (e.g., cable 803). A fourth bus unit (e.g., fourth bus unit 840) is configured to generate (e.g., transmit) a system wake-up signal 853 at a fourth time (e.g., time 3 following the third time) in response to the system wake-up signal 852. The system wake-up signal 853 is generated at a fourth output (e.g., cable 804).

[0142] 9 is a block diagram of a second example wake-up signal processing scenario in an example system. In this example, system 900 includes serially concatenated bus units such as 910, 920, 930, and 940. The bus units may be deserializers and / or disaggregators.

[0143] FBU910 may be similar to multi-stream generator 410 and / or FBU510. FBU910 may be locally coupled to various devices (e.g., sensor 402 and head unit 401) and may generate a local wake-up signal in response to input generated by any coupled sensor. FBU910 is upstream of SBU920. FBU910 is coupled to SBU920 via cable 901. Cable 901 (and each of cables 902, 903, and 904) may be a cable harness including conductors for transmitting and / or receiving a wake-up signal. In some examples, conductors reserved as "lanes" for video streaming in active mode may be used to transmit a wake-up signal to an adjacent bus unit in power saving mode.

[0144] The FBU 910 is coupled to a second bus unit (SBU) 920 via cable 901. The SBU 920 is locally coupled to a touch display 926 (which may be similar to the touch display 572) via cable 924, where the SBU 920 is configured to disaggregate video (by switch 922) in active mode and send the disaggregated stream to the touch display 926. The SBU 920 is coupled to a third bus unit (TBU) 930 via cable 902. The TBU 930 is locally coupled to a touch display 936 (which may be similar to the touch display 573) via cable 934, where the TBU 930 is configured to disaggregate video (by switch 932) in active mode and send the disaggregated stream to the touch display 936. The TBU 930 is generated to a fourth bus unit 940 via cable 903. The fourth bus unit 940 is locally coupled to a touch display 946 (which may be similar to touch display 574) via cable 944, and the fourth bus unit 940 is configured to disaggregate the video (via switch 942) in active mode and send the disaggregated stream to the touch display 946. The fourth bus unit 940 may be coupled to an adjacent (e.g., downstream) bus unit via cable 904 (more downstream bus units may be serially chained along the system bus, and each of the additional downstream units may be locally coupled using similar circuitry).

[0145] In a second example scenario, a first bus unit (e.g., SBU 920) is configured to generate (e.g., transmit) a system wake-up signal 950 at a first time (e.g., time T0) in response to a user wake-up signal (e.g., generated by the touch display 926). The system wake-up signal 950 is generated at a first output (e.g., cable 901). The first bus unit (e.g., SBU 920) is further configured to generate (e.g., transmit) a system wake-up signal 951 at a first time (e.g., time T0) in response to a user wake-up signal (e.g., generated by the touch display 926). The system wake-up signal 951 is generated at a second output (e.g., cable 902). A second bus unit (e.g., TBU 930) is configured to generate (e.g., transmit) a system wake-up signal 952 at a second time (e.g., time T1 following the first time) in response to the system wake-up signal 951. The system wake-up signal 952 is generated at a third output (e.g., cable 903). A third bus unit (e.g., fourth bus unit 940) is configured to generate (e.g., transmit) a system wake-up signal 953 at a third time (e.g., time T2 following the second time) in response to the system wake-up signal 952. The system wake-up signal 953 is generated at a fourth output (e.g., cable 904).

[0146] 10 is a block diagram of a third example wake-up signal processing scenario in an example system. In this example, a system 1000 includes serially concatenated bus units such as 1010, 1020, 1030, and 1040. The bus units may be deserializers and / or disaggregators.

[0147] The FBU 1010 may be similar to the multi-stream generator 410 and / or the FBU 510. The FBU 1010 may be locally coupled to various devices (e.g., the sensor 402 and the head unit 401) that may generate a local wake-up signal in response to input generated by any coupled sensor. The FBU 1010 is upstream of the SBU 1020. The FBU 1010 is coupled to the SBU 1020 via the cable 1001. The cable 1001 (and each of the cables 1002, 1003, and 1004) may be a cable harness that includes conductors for transmitting and / or receiving the wake-up signal. In some examples, the conductors reserved as "lanes" for video streaming in active mode may be used to transmit the wake-up signal to adjacent bus units that are in power saving mode.

[0148] The FBU 1010 is coupled to a second bus unit (SBU) 1020 via cable 1001. The SBU 1020 is locally coupled to a touch display 1026 (which may be similar to touch display 572) via cable 1024, where the SBU 1020 is configured to disaggregate video (by switch 1022) in active mode and send the disaggregated stream to the touch display 1026. The SBU 1020 is coupled to a third bus unit (TBU) 1030 via cable 1002. The TBU 1030 is locally coupled to a touch display 1036 (which may be similar to touch display 573) via cable 1034, where the TBU 1030 is configured to disaggregate video (by switch 1032) in active mode and send the disaggregated stream to the touch display 1036. TBU 1030 is coupled to a fourth bus unit 1040 via cable 1003. The fourth bus unit 1040 is locally coupled to a touch display 1046 (which may be similar to touch display 574) via cable 1044, and the fourth bus unit 1040 is configured to disaggregate video (by switch 1042) in active mode and send the disaggregated stream to the touch display 1046. The fourth bus unit 1040 may be coupled to an adjacent (e.g., downstream) bus unit via cable 1004 (where more downstream bus units may be chained in series along the system bus, and each of the additional downstream units may be locally coupled using similar circuitry).

[0149] In a third example scenario, a first bus unit (e.g., SBU 1030) is configured to generate (e.g., transmit) a system wake-up signal 1050 at a first time (e.g., time T0) in response to a user wake-up signal (e.g., generated by the touch display 1036). The system wake-up signal 1050 is generated at a first output (e.g., cable 1002). The first bus unit (e.g., SBU 1030) is further configured to generate (e.g., transmit) a system wake-up signal 1051 at a first time (e.g., time T0) in response to a user wake-up signal (e.g., generated by the touch display 1036). The system wake-up signal 1051 is generated at a second output (e.g., cable 1003). A second bus unit (e.g., TBU 1020) is configured to generate (e.g., transmit) a system wake-up signal 1052 at a second time (e.g., time T1 following the first time) in response to the system wake-up signal 1050. The system wake-up signal 1052 is generated at a third output (e.g., cable 1001). A third bus unit (e.g., fourth bus unit 1040) is configured to generate (e.g., transmit) a system wake-up signal 1053 at a second time (e.g., time T1 following the first time) in response to the system wake-up signal 1051. The system wake-up signal 1053 is generated at a fourth output (e.g., cable 1004).

[0150] 11 is a block diagram of another example system including at least one stream disaggregator adapted to selectively forward transmissions between serially-chained devices. For example, system 1100 is an example system including a source 1101, a serializer 1110 (coupled to source 1101 via cable 1102), a deserializer 1120 (e.g., locally coupled to a local display 1104 via cable 1105), a deserializer 1130 (e.g., locally coupled to a local display 1106 via cable 1107), and a deserializer 1140 (e.g., locally coupled to a local display 1108 via cable 1109).

[0151] The cables 1111, 1112, and 1113 each include a physical medium over which a system protocol (e.g., a system bus) is implemented. The system protocol can be either unidirectional or bidirectional. In implementing a bidirectional system protocol, a first bidirectional serial link is established between the serializer 1110 and the deserializer 1120 via the cable 1111 (which is coupled between the serializer 1110 and the deserializer 1120), a second bidirectional serial link is established between the deserializer 1120 and the deserializer 1130 via the cable 1112 (which is coupled between the deserializer 1120 and the deserializer 1130), and a third bidirectional serial link is established between the deserializer 1130 and the deserializer 1140 via the cable 1113 (which is coupled between the deserializer 1130 and the deserializer 1140).

[0152] The bidirectional serial link can be either asymmetric or symmetric. An exemplary asymmetric bidirectional link includes an upstream rate of 165 megabits per second (e.g., for bit traffic directed toward the serializer 1110) and a downstream rate of 13 gigabits per second (e.g., for bit traffic directed away from the serializer 1110). The asymmetric rate allows high-definition video to be sent downstream at high speeds (e.g., to send various high-definition video streams to selected displays), while also allowing a robust bidirectional system control and communication link between devices. The exemplary asymmetric bidirectional link includes symmetric data rates, so that data can be transmitted at full rate in either direction.

[0153] In one example, source 1101 is a source such as head unit 401. Source 1101 is coupled to serializer 1110 via cable 1102. Cable 1102 is arranged to carry at least one video stream according to a protocol such as MIPI CIS.

[0154] In this example, the serializer 1110 is a serializer, such as the multi-stream generator 410. The serializer 1110 includes a transmitter 1190, such as the transmitter 390, that is adapted to transmit a multi-stream (e.g., that includes reformatted information of at least one video stream generated by the serializer 1110 and conveyed via the cable 1102) so that the deserializer 1120 can receive and process (e.g., process a portion of) the transmitted multi-stream.

[0155] In this example, the deserializer 1120 is a deserializer, such as the stream disaggregator 420. The deserializer 1120 is coupled to the serializer 1110 via a cable 1111. The deserializer 1120 includes a receiver 1122 (such as the receiver 422) arranged to receive information transmitted by the transmitter 1190. The deserializer 1120 includes a transmitter 1126 (such as the stream forwarder 426) arranged to transmit information received from the transmitter 1190. The cable 1111 is arranged to carry the multi-stream output transmitted by the transmitter 1190 according to a protocol such as FPD-Link IV. The deserializer 1120 is locally coupled to a local display 1104 (such as the local display 404) via a cable 1105. The cable 1105 is arranged to carry a selected video stream according to a protocol such as eDP (Extended Display Protocol).

[0156] In this example, the deserializer 1130 is a deserializer, such as the stream disaggregator 430. The deserializer 1130 is coupled to the serializer 1120 via a cable 1112. The deserializer 1130 includes a receiver 1132 (such as the receiver 422) arranged to receive information transmitted by the transmitter 1126. The deserializer 1130 includes a transmitter 1136 (such as the stream forwarder 426) arranged to transmit information received from the transmitter 1126. The cable 1112 is arranged to carry the multi-stream output transmitted by the transmitter 1126 according to a protocol such as FPD-Link IV. The deserializer 1130 is locally coupled to a local display 1106 (such as the local display 406) via a cable 1107. The cable 1107 is arranged to carry a selected video stream according to a protocol such as eDP.

[0157] In this example, the deserializer 1140 is a deserializer, such as the stream disaggregator 440. The deserializer 1140 is coupled to the serializer 1130 via a cable 1113. The deserializer 1140 includes a receiver 1142 (such as the receiver 422) arranged to transmit information transmitted by the transmitter 1136. The deserializer 1140 optionally includes a transmitter 1146 (such as the stream forwarder 426) arranged to transmit information received from the transmitter 1136. The cable 1113 is arranged to carry the multi-stream output transmitted by the transmitter 1136 according to a protocol such as FPD-Link IV. The deserializer 1140 is locally coupled to a local display 1108 (such as the local display 408) via a cable 1109. The cable 1109 is arranged to carry a selected video stream according to a protocol such as eDP.

[0158] For example, if the last deserializer in the chain receives only data intended (e.g., addressed) to be displayed on a respective local display locally coupled to the last deserializer, the last deserializer does not need to include a switch such as switch 427.

[0159] Modifications are possible in the described embodiments and other embodiments are possible within the scope of the claims.

Claims

1. 1. A circuit comprising: A transceiver; A controller; An energy detector; Including, the transceiver having a first system port, a second system port, a local port, and a wake-up input, the first system port adapted to receive a first system input signal, the second system port adapted to receive a second system input signal, and the local port adapted to receive a local input signal; the transceiver is configured in a first mode to transmit data of the first system input signal to the second system port, the transceiver is configured in a second mode to conserve power, the transceiver is configured to enter the first mode in response to a local wakeup signal, and the transceiver is configured to transmit a system wakeup signal at the second system port in response to the local wakeup signal; the controller has an energy detect input and a wake-up output, the wake-up output coupled to the wake-up input, the controller configured to generate the local wake-up signal at the wake-up output in response to an energy detect signal; a circuit configured to generate the energy detect signal at the energy detect output in response to detecting energy in one of the first system input signal and the local input signal received by the transceiver in the second mode, the circuit having an energy detect output coupled to the energy detect input, the energy detector coupled to the first system port and the local port, the energy detector configured to generate the energy detect signal at the energy detect output in response to detecting energy in one of the first system input signal and the local input signal received by the transceiver in the second mode.

2. 2. The circuit of claim 1, The circuitry further comprising: the transceiver configured, in the first mode, to transmit data on the second system input signal to the first system port.

3. 3. The circuit of claim 2, The circuit, wherein the system wake-up signal comprises a wake-up pattern.

4. 2. The circuit of claim 1, The circuitry further configured, in the second mode, for the transceiver to transmit the system wakeup signal at the first system port in response to the local wakeup signal.

5. 2. The circuit of claim 1, The circuit, wherein the energy detector is configured to detect energy in one of the first system input signal and the local input signal.

6. 6. The circuit of claim 5, A circuit, wherein the energy detector is coupled to the second system port, the energy detector configured to detect energy of the second system input signal.

7. 7. A circuit according to claim 6, comprising: a circuit configured to generate the energy detect signal at the energy detect output in response to detecting energy in the second system input signal received by the transceiver in the second mode;

8. 2. The circuit of claim 1, The circuit, wherein the controller is further coupled to the first system port and the local port, the controller further configured to detect a wake-up pattern in one of the first system input signal and the local input signal in response to the energy detection signal.

9. 9. The circuit of claim 8, the controller further includes a data valid output, the controller being configured to generate a data valid signal at the data valid output in response to detecting the wake-up pattern in one of the first system input signal and the local input signal.

10. 10. The circuit of claim 9, The circuit, wherein the energy detector further includes a data valid input and an enable power output, the data valid input coupled to the data valid output, the energy detector further configured to generate an enable power signal at the enable power output.

11. 11. The circuit of claim 10, The circuit further includes a power manager, the power manager including an enable power input and a power supply output, the enable power input coupled to the enable power output, and the power manager configured to generate a power signal at the power supply output in response to the enable power signal.

12. 12. The circuit of claim 11, The circuit, wherein the controller further includes a power supply input, the power supply input coupled to the power supply output, the controller further configured to generate the local wake-up signal in response to the power signal.

13. 13. The circuit of claim 12, The circuit, wherein the power manager further includes a logic enable output, the controller further includes a logic enable input, the logic enable input coupled to the logic enable output, the power manager further configured to generate a logic enable signal at the logic enable output in response to the power signal, and the controller further configured to generate the local wake-up signal in response to the logic enable signal.

14. 1. A system comprising: a first bus unit (FBU); a second bus unit (SBU); Including, the FBU having an FBU first system port, an FBU local port, an FBU wake-up input, an FBU transceiver, an FBU controller, and an FBU energy detector; the FBU transceiver is coupled to the FBU first system port, the FBU local port, and the FBU wakeup input, the FBU first system port is adapted to receive an FBU first system input signal, the FBU local port is adapted to receive an FBU local input signal, the FBU transceiver is configured to transmit data of the FBU first system input signal to the FBU local port in an FBU first mode, the FBU transceiver is configured to save power in an FBU second mode, the FBU transceiver is configured to enter the FBU first mode in response to an FBU local wakeup signal, and the FBU transceiver is configured to transmit an FBU system wakeup signal at one of the FBU first system port and the FBU local port in response to the FBU local wakeup signal; the FBU controller has an FBU energy detect input and an FBU wakeup output, the FBU wakeup output being coupled to the FBU wakeup input, the FBU controller being configured to generate the FBU local wakeup signal at the FBU wakeup output in response to an FBU energy detect signal; the FBU energy detector has an FBU energy detect output coupled to the FBU energy detect input, the FBU energy detector is coupled to the FBU first system port and the FBU local port, and the FBU energy detector is configured to generate the FBU energy detect signal at the FBU energy detect output in response to FBU detection of energy in one of the FBU first system input signal and the FBU local input signal received by the FBU transceiver in the FBU second mode; A system, wherein the SBU has an SBU first system port, the SBU first system port coupled to the FBU first system port, the SBU first system port adapted to receive the FBU system wake-up signal, and the FBU first system port adapted to receive an SBU system wake-up signal generated by the SBU.

15. 15. The system of claim 14, the SBU further includes an SBU second system port, an SBU local port, an SBU wake-up input, an SBU transceiver, an SBU controller, and an SBU energy detector; the SBU transceiver is coupled to the SBU first system port, the SBU second system port, the SBU local port, and the SBU wakeup input, the SBU first system port being adapted to receive an SBU first system input signal; the SBU second system port is adapted to receive an SBU second system input signal; the SBU local port is adapted to receive an SBU local input signal; the SBU transceiver is configured to transmit data of the SBU first system input signal to the SBU second system port in an SBU first mode, the SBU transceiver is configured to save power in an SBU second mode, the SBU transceiver is configured to enter the SBU first mode in response to an SBU local wakeup signal, and the SBU transceiver is configured to transmit the SBU system wakeup signal at one of the SBU first system port and the SBU second system port in response to the SBU local wakeup signal; the SBU controller has an SBU energy detect input and an SBU wakeup output, the SBU wakeup output being coupled to the SBU wakeup input, the SBU controller being configured to generate the SBU local wakeup signal at the SBU wakeup output in response to an SBU energy detect signal; a first system port, a second system port, and a first local port; and a second system port, the second system port, and the first local port are coupled to the SBU local port; and the SBU energy detector is configured to generate the SBU energy detect signal at the SBU energy detect output in response to SBU detection of energy in one of the SBU first system input signal, the SBU second system input signal, and the SBU local input signal received by the SBU transceiver in the SBU second mode.

16. 16. The system of claim 15, a third bus unit (TBU) having a TBU first system port, a TBU local port, a TBU wake-up input, a TBU transceiver, a TBU controller, and a TBU energy detector; the TBU first system port is coupled to the SBU second system port, the TBU first system port being adapted to receive the SBU system wake-up signal; the TBU transceiver is coupled to the TBU first system port, the TBU local port, and the TBU wake-up input, the TBU first system port being adapted to receive a TBU first system input signal; the TBU local port is adapted to receive a TBU local input signal, the TBU transceiver is configured in a TBU first mode to transmit data of the TBU first system input signal to the TBU local port, the TBU transceiver is configured in a TBU second mode to save power, the TBU transceiver is configured to enter the TBU first mode in response to a TBU local wakeup signal, and the TBU transceiver is configured to transmit a TBU system wakeup signal at one of the TBU first system port and the TBU local port in response to the TBU local wakeup signal; the TBU controller has a TBU energy detect input and a TBU wakeup output, the TBU wakeup output being coupled to the TBU wakeup input, the TBU controller being configured to generate the TBU local wakeup signal at the TBU wakeup output in response to a TBU energy detect signal; A system, wherein the TBU energy detector has a TBU energy detect output coupled to the TBU energy detect input, the TBU energy detector is coupled to the TBU first system port and the TBU local port, and the TBU energy detector is configured to generate the TBU energy detect signal at the TBU energy detect output in response to TBU detection of energy in one of the TBU first system input signal and the TBU local input signal received by the TBU transceiver, in the TBU second mode.

17. 17. The system of claim 16, The system further includes a user interface (UI) device, the UI device including a UI port coupled to the SBU local port, the UI device adapted to receive user input, the SBU configured to generate a user wakeup signal at the UI port in response to the user input, the SBU configured to generate the SBU system wakeup signal in response to the user wakeup signal, the FBU configured to generate the FBU local wakeup signal in response to the SBU system wakeup signal, and the TBU configured to generate the FBU local wakeup signal in response to the SBU system wakeup signal.

18. 1. A method comprising: receiving, by a first bus unit (FBU) transceiver, from a second bus unit (SBU) first system port, an SBU system wakeup signal transmitted by the SBU; transmitting, in an SBU first mode, data of the SBU first system input signal to an SBU second system port by the SBU transceiver; saving power by the SBU in an SBU second mode, the SBU transceiver being configured to enter the SBU first mode from the SBU second mode in response to an SBU local wakeup signal; transmitting, by the SBU transceiver, an SBU system wakeup signal at the SBU first system port in response to the SBU local wakeup signal; generating, by an SBU controller, an SBU local wake-up signal in response to an SBU energy detect signal; detecting, by an SBU energy detector, the energy of one of an SBU second system input signal and an SBU local input signal received by the SBU transceiver in the SBU second mode; generating, by the SBU energy detector, the SBU energy detect signal in response to detection by the SBU energy detector of one of the SBU second system input signal and the SBU local input signal, wherein in the SBU second mode, the one of the SBU second system input signal and the SBU local input signal is received by the SBU transceiver; transmitting the SBU system wakeup signal by the SBU transceiver at the SBU first system port; A method comprising:

19. 20. The method of claim 18, The method further comprising transmitting, by the SBU transceiver, the SBU system wakeup signal at the SBU second system port.

20. 20. The method of claim 19, receiving, by a third bus unit (TBU), the SBU system wake-up signal transmitted via the SBU second system port; and generating, by the TBU, a TBU wake-up signal.

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