Operating a universal data transport system

Abstract

The invention relates to a method for operating a universal data transport system which is designed specially for vehicle architectures because there are special limitations here. The aim of the invention is achieved by the proposed method or the data transport system in that particularly hardware-efficient data can be transported. The hardware efficiency reflects that, for example, only one physical data channel is necessary and the corresponding components can be provided with little complexity. The invention additionally relates to a data transport system which carries out the proposed method or a computer program with control commands, said computer program carrying out the method or operating the data transport system. The invention additionally relates to a computer-readable storage medium.

Description

[0001] Operating a universal data transport system

[0002] The present invention is directed to a method for operating a universal data transport system, which was specifically designed for vehicle architectures, due to particular limitations in this area. The proposed method and data transport system are based on the particularly hardware-efficient transport of data. This hardware efficiency is reflected in the fact that, for example, only one physical data channel is required and the corresponding components can be provided with low complexity. The present invention is further directed to a data transport system that implements the proposed method and to a computer program product with control commands that implement the method and operate the data transport system. Furthermore, a computer-readable storage medium is proposed.

[0003] Various video interfaces are known from the state of the art, which are typically optimized for transmitting data over a computer network and then outputting it on a conventional terminal device. The state of the art typically assumes that powerful computer systems are available and that sufficient bandwidth is always available. Furthermore, such technologies do not focus on energy efficiency. Energy efficiency typically plays a subordinate role in computer systems, with only temperature development and heat dissipation being considered. In automobiles, however, energy consumption directly reduces the range of an electrically powered vehicle.

[0004] Well-known interfaces such as DisplayPort or HDMI typically assume a high bandwidth for the underlying data channel and are not optimized for latency.

[0005] Other state-of-the-art transmission systems also rely on a high-bandwidth data connection and transmit data packets over long distances. Technologies used in today's internet are typically packet-based and overcome large geographical distances using dynamic routing. This requires high-performance network nodes that find an optimal data path through a wide-area computer network at runtime. However, completely different requirements arise in automobiles, as the spatial extent is smaller and data is often security-relevant. Therefore, state-of-the-art technologies are often not applicable due to increased security and real-time requirements.

[0006] The example interfaces listed are each optimized for specific use cases (data types). Depending on the type of interface, they offer either (but not simultaneously):

[0007] Low latency for unidirectional point-to-point or multipoint connection of a specific application less than or equal to 16 nodes (Consumer Video Interfaces: DP / HDMI / DSI / CSI / LVDS)

[0008] Low latency for bidirectional point-to-point or multipoint connections with a fixed frame format (and thus fixed allocated bandwidth) to meet latency requirements (APIX2 / APIX3)

[0009] High latency for point-to-point and multipoint connections with high flexibility (Ethernet, TDM)

[0010] The following requirements cannot be met simultaneously for the interfaces mentioned as examples:

[0011] Lowest latency (through possible prioritization)

[0012] Dynamically allocated bandwidth (no fixed frame format)

[0013] Bidirectional data streams

[0014] (Multi-master) multipoint data streams > 16 nodes

[0015] Bundling of all conceivable data types Gateway function is available everywhere in the network

[0016] Low protocol overhead as possible

[0017] The simultaneous combination of all of these features is desirable as a universal data transport system for new vehicle architectures, as it meets both the increasing complexity and growing bandwidth requirements. This is currently not possible.

[0018] There is a need to propose a method that enables efficient data transmission, regardless of data type, especially in vehicle architectures. The proposed method is intended to achieve a minimal technical effort and to enable data transport across multiple network nodes, regardless of the data formats provided, with the network nodes being of low complexity and the structural features being lightweight. Furthermore, it is an object of the present invention to provide a correspondingly configured data transport system, as well as a computer program product and a computer-readable storage medium.

[0019] The problem is solved by the features of patent claim 1. Further advantageous embodiments are specified in the subclaims.

[0020] Accordingly, a method for operating a universal data transport system for vehicle architectures is proposed, comprising dividing at least one physical data channel into a plurality of virtual data channels; reading out payload data in a transmitter of the data transport system; adding description data to the payload data according to a target data format to create at least one data set; transmitting the at least one data set by means of the virtual data channels from the transmitter to a receiver based on static addressing; and receiving the at least one data set in the receiver and reading out the payload data for use therein.

[0021] The data transport system set forth below can, according to one aspect of the present invention, combine all of the above-mentioned requirements simultaneously.

[0022] The desired properties are achieved according to one aspect of the present invention by:

[0023] 128 virtual data paths, each of which is dynamically allocated bandwidth (based on prioritization), and which only require bandwidth when data is being transferred.

[0024] Two generic application adaptation units for burst and stream data, which enable the integration of all conceivable interfaces

[0025] A segmentation or reassembly unit for each of the send and receive paths that enables the transition of application data into the uniform cell format

[0026] A service-independent peer-to-peer interface at the cell layer that enables low-latency repeater / routing functionality in all directions.

[0027] This is necessary for the arbitrary forwarding (routing) of the individual virtual data paths

[0028] A crossbar unit for cell merge (TX path) or cell separation (RX path)

[0029] Full-duplex design of each serial interface: All 128 virtual channels can be operated in full-duplex mode if required

[0030] The ability to create multiple serial interfaces (x2 x3 x4, etc.) for increased bandwidth. It's also possible to use an asymmetric configuration, e.g., two TX PHYs and only one RX PHY (double the downstream bandwidth, while the upstream remains unaffected).

[0031] This makes it possible to bundle burst and stream data with minimal latency. This, in turn, enables, thanks to the bidirectional structure, the simultaneous bundling of a large number of interfaces across multiple functional units in any direction with any input and output points. The proposed method for operating the data transport system is based on the data transport system being universal with regard to the payload data to be transmitted. Thus, the invention makes it possible for the payload data to be extracted during data transmission of any data format and then, if necessary, repackaged and forwarded. Data transmitted in a computer network typically contains overhead. This data can be, for example, frame data, header data, or footer data. These are format-specific, while the payload data contains the actual information.According to the invention, a method is proposed that separates the overhead data from the payload data and is thus suitable for universal data formats. Potentially, any data format can be converted into another data format.

[0032] The proposed data transport system comprises several network nodes connected via serial data channels, e.g., a cable. The topology is static, meaning no dynamic routing or addressing is performed, as the network topology is known in advance and can be omitted for efficiency reasons.

[0033] According to the proposed method, a physical data channel is operated which is divided into a plurality of virtual data channels. Preferably, a physical data channel is divided into 128 virtual channels. In general, it is also possible to provide multiple physical data channels, which are then in turn split into virtual data channels. In general, it is also possible to provide a first number of physical data channels for a first communication direction and a second number of physical data channels for a second communication device. How physical data channels are divided into virtual data channels is well known, although the invention proposes that the virtual data channels can be addressed independently of one another.

[0034] Thus, according to the invention, it is possible to operate the virtual data channels in such a way that they have different bandwidths and implicitly different latencies. Furthermore, individual data channels can be prioritized. Furthermore, payload data is read out in a transmitter of the data transport system, which can occur in such a way that the payload is read out from a data source or the sender has previously acted as a receiver and the payload data was transmitted. Reading out payload data can also involve reading the payload data from a data stream, whereby overhead data, for example frame data, was also transmitted. Reading out the payload data then corresponds to extracting the payload data from a larger data set that has been transmitted. How the payload data is extracted from the data stream or from data packets can be determined based on the overhead data.For example, the payload data is transmitted in a certain data format, whereby the data format itself provides information about where the payload data can be found within the overall transmitted data. Furthermore, reading payload data can imply additional components, such as reading a sensor or reading a data storage device, for example, a volatile data storage device.

[0035] In a subsequent method step, descriptive data is added to the payload data according to a target data format to create at least one data record. The descriptive data provides information about the content of the payload data or describes the payload data. While the payload data describes the generic raw data, the descriptive data is there to provide metadata that relates in some way to the payload data. In this case, it is not necessary for addressing data to be present, since static addressing takes place according to the invention. The target data format can be specified by a network node of the data transport system and determines which data format a recipient of the descriptive data and the payload data can read out. The target data format also makes it clear which descriptive data is to be added to the payload data.The resulting data set then corresponds to the target data format and optionally has descriptive data and also has the payload. The at least one data set is then transmitted via the virtual data channels or at least one data channel. When transmitting the at least one data set from the sender to the receiver, no addressing information or dynamic routing is used; rather, according to the invention, static routing or static addressing is carried out. This is particularly advantageous in a system architecture in an automobile, since all network nodes are known in advance or this can be determined in an initialization step. The network nodes are hard-wired, and thus static addressing can also be specified.This creates the advantage that the complexity of the individual network nodes can be kept low, thus resulting in error robustness and a lighter weight.

[0036] Static addressing can be performed for each physical data channel or for each virtual data channel. This allows addressing information to be specified that indicates the destination network node. Generally, it is possible for each network node to decide to which subsequent node the data set is transmitted, but this is always statically specified. Alternating data paths within the network nodes is not provided. Thus, addressing or routing occurs, but this is static and does not vary over time.

[0037] After the at least one data set has been transmitted, the at least one data set is received by the receiver, which also represents a network node of the data transport system. The payload is then read out for use, which may mean that the payload is output via an output unit or that it is further processed. Further processing may involve enriching the read payload with descriptive data, and the receiver assumes the role of the sender and transmits the enriched payload to another receiver.

[0038] According to one aspect of the present invention, the number of virtual

[0039] A maximum of 128 data channels per physical data channel is possible. This has the advantage that the proposed method can be implemented particularly advantageously, since 128 virtual data channels ensure that sufficient bandwidth is available for each data channel and, in addition, a suitable bit length is available, which can be particularly advantageously utilized with regard to disparity. It was discovered that 112 bits can be particularly advantageously encoded with a bit length of 128, which corresponds to minimal overhead. The present invention takes this approach and creates data channels of up to 128 per physical data channel.

[0040] According to a further aspect of the present invention, a bandwidth is allocated separately for each virtual data channel. This has the advantage that the data channels can be configured differently depending on the application scenario, and individual data channels can also be prioritized by assigning them a higher bandwidth. Bandwidth allocation can also occur dynamically at runtime.

[0041] According to a further aspect of the present invention, all virtual data channels are operated at least temporarily in duplex mode. This has the advantage that both a simplex mode is possible, but full duplex mode can be switched to at any time or at least temporarily. This means that the data channels, whether physical data channels or virtual data channels, are operated in a bidirectional mode, allowing data to be sent simultaneously in both directions.

[0042] According to a further aspect of the present invention, a different number of physical and / or virtual data channels are present for each communication direction. This has the advantage that, in directed data communication, directed physical and / or virtual data channels can be present that do not need to be the same. This makes it possible to take into account the fact that more data needs to be sent upstream or downstream, and to this extent, the corresponding communication direction can be amplified accordingly. This creates the transmission capacity required in the respective application scenario. According to a further aspect of the present invention, virtual data channels are set up exclusively for continuous or discontinuous data sets. This has the advantage that individual interfaces or data channels are provided either for streaming data or for burst data.This allows particularly efficient structural features to be created, or the method can utilize these structural features. For example, the buffers can be designed larger for continuous data than for discontinuous data. The bandwidths for continuous data on the data channel can also be selected accordingly.

[0043] According to a further aspect of the present invention, virtual data channels are prioritized independently of one another. This has the advantage that the bandwidth can be adjusted dynamically at runtime, or data channels can be bundled. Furthermore, latency times can be specified that must be adhered to, and the data channels are loaded or configured accordingly.

[0044] According to a further aspect of the present invention, network nodes of the data transport system act alternately as transmitters or receivers. This has the advantage that the role of transmitter or receiver can be assumed by network nodes alternately, allowing different network topologies to be created. Thus, it is possible to have network nodes that represent only data sources (i.e., transmitters) or network nodes that represent only data sinks (i.e., data receivers). Furthermore, there can also be addressing network nodes that act as both transmitters and receivers.

[0045] According to a further aspect of the present invention, the payload data is output in the receiver by means of an output unit and / or the receiver represents a data sink. This has the advantage that individual network nodes can only receive data and these output the data, for example, using a screen and / or a loudspeaker and do not generate any data of their own. Such network nodes can then be referred to as data sinks. According to a further aspect of the present invention, the method uses only volatile memory. This has the advantage that no data is stored persistently and therefore the network components or network nodes do not have to be designed in a complex way. Volatile memory is typically faster and more efficient than persistent memory. This is based on the application scenario in automobiles, which requires particularly simply designed components.

[0046] According to a further aspect of the present invention, bidirectional routing is implemented within the transmitters. This has the advantage that there are individual network nodes that serve as routers or addressing units, or also as so-called gateway routers.

[0047] According to a further aspect of the present invention, the payload data is present as video data and / or audio data. This has the advantage of creating a method that specifically addresses the requirements of automobiles and allows for efficient transmission of even larger data volumes. The invention can be implemented particularly advantageously with this data, since static addressing allows for efficient transmission of even large data volumes, and there are no high latencies. Thus, these real-time applications can be transmitted particularly advantageously using the present method, since video data and audio data must always be transmitted continuously.

[0048] One aspect of the present invention is to bundle multiple data streams (video, audio, and data) into a transport frame and transmit them serially. The different data formats have not only different bandwidth requirements, but also different latency, reassembly sublayer, and bit error rate requirements. In particular, the transmission of today's video data formats requires not only the transmission of the pure video data and its frame information, but also support for encryption methods such as HDCP. All of this requires many different data channels with very different requirements for bandwidth, latency, reassembly sublayer, etc. Added to this is the desire for far more complex network architectures than a simple transmitter-receiver architecture offers.Architectures with multiple repeaters, where data paths can start and end, branches (Y) also with the possibility of integrating data paths back into a link, are advantageous.

[0049] According to one aspect of the present invention, the technology follows the fundamental idea of ​​consistently bundling multiple services, but offers completely new possibilities regarding network architectures and allows for new approaches to implementing today's video interfaces. Furthermore, it can be used as a universal data transport layer, for example, for transmitting Ethernet or camera data or any type of sensor data.

[0050] With a virtual path, all packets / cells take the same path, unlike IP, where a packet could reach its destination via a different route than previous and subsequent packets. Latency and the reassembly sublayer across a virtual path are thus constant.

[0051] Virtual paths also have the advantage that they can be used as a multiplexing layer for different services (video, audio, Ethernet), since the properties of the virtual paths can be configured differently without the different virtual paths interfering with each other.

[0052] Virtual paths only consume bandwidth when data is actually being transferred.

[0053] The concept of virtual paths also makes it possible to implement complex and extensive diagnostic and network configuration functions at runtime using dedicated (virtual) data channels.

[0054] According to one aspect of the present invention, a virtual path layer is implemented between the physical layer (serializer and framer) and the various application data interfaces. According to one aspect of the present invention, this layer is used to multiplex the various data paths and support more complex architectures with repeaters and branches. This occurs primarily in the cell layer.

[0055] According to one aspect of the present invention, another part of the Virtual Path layer is an application adaptation layer, which performs the conversion of video (stream) or, for example, Ethernet (packet) data into cells. This application adaptation layer also includes the OAM functions for network diagnostics and management.

[0056] According to one aspect of the present invention, the technology can form the basis for transmitting a variety of data formats over a serial connection in the car (and elsewhere). It thus forms the basis for a new generation of devices.

[0057] The high serial bandwidths make it necessary to define architectures, cell formats and interfaces that enable flexible internal data bus widths in order to adapt the speed of the internal clock system to the capabilities of the chip technology.

[0058] According to one aspect of the present invention, the Virtual Path layer includes the physical layer, which consists of the transmission sublayer and the physical medium sublayer, the cell layer and the application adaptation layer, which contains the segmentation and reassembly sublayer and the functions for adapting the data formats to the corresponding application.

[0059] The main task of the physical layer is to establish the physical connection to other physical layers. This connection is fundamentally bidirectional. Theoretically, this connection can be realized using a variety of media. In practice, two serial differential GBps connections are used. Line coding, the insertion of dummy cells to decouple the cell rate from the link rate, and the integration of the cell stream into the serial frame take place in this layer.

[0060] In the cell layer, the segmented data (cell payload) of the overlying Segmentation & Reassembly sublayer is assembled into complete cells with a header, VP identifier, and CRC, or cells are CRC-checked, and the payload is passed to the Segmentation & Reassembly sublayer. This is also where the various cell streams of the application adaptation functions are multiplexed, or the cell payloads are distributed among the application adaptation functions according to the VP identifier (feed-in / feed-out).

[0061] According to one aspect of the present invention, the multiplexing and demultiplexing of cell streams in repeaters and splitters (forwarding) also takes place in the cell layer.

[0062] According to one aspect of the present invention, the task of the application adaptation functions is to adapt the data of the application interfaces to the format of the payload field of the cell and to transmit control information to the other side or to use control information of the other side for the adaptation (time generation, frame formation).

[0063] According to one aspect of the present invention, all virtual data paths are unidirectional, meaning they start at an initiator and end at one or more destinations. If virtual data paths belong together logically, e.g., HDCP for a video channel, and thus form a bidirectional data path, these paths should have the same VP identifiers.

[0064] The virtual data path starts at an initiator and ends at one or more targets. It is implemented by the

[0065] Cell sublayer and performs the following functions on the virtual path:

[0066] - Add / delete multiplexing - VP translation

[0067] The object is also achieved by a data transport system for vehicle architectures comprising a subdivision unit configured to subdivide at least one physical data channel into a plurality of virtual data channels; an interface unit configured to read out payload data in a transmitter of the data transport system; a packaging unit configured to add description data to the payload data according to a target data format to create at least one data set; a transmission interface unit configured to transmit the at least one data set by means of the virtual data channels from the transmitter to a receiver based on static addressing; and a reception interface unit configured to receive the at least one data set in the receiver and read out the payload data for use therein.

[0068] The problem is also solved by a computer program product with control commands which implement the proposed method or operate the proposed device.

[0069] According to the invention, it is particularly advantageous that the method can be used to operate the proposed devices and units. Furthermore, the proposed devices and units are suitable for implementing the method according to the invention. Thus, each device implements structural features suitable for executing the corresponding method. However, the structural features can also be configured as method steps. The proposed method also provides steps for implementing the function of the structural features. Furthermore, physical components can also be provided virtually or in a virtualized form.

[0070] Further advantages, features and details of the invention will become apparent from the following description, in which aspects of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. Likewise, the features mentioned above and those further explained here can each be used individually or in groups in any combination. Parts or components with similar functions or that are identical are sometimes provided with the same reference numerals. The terms “left”, “right”, “top” and “bottom” used in the description of the exemplary embodiments refer to the drawings in an orientation with normally legible figure designations or normally legible reference numerals.The embodiments shown and described are not intended to be exhaustive, but rather are exemplary in nature to illustrate the invention. The detailed description is intended to inform those skilled in the art; therefore, known circuits, structures, and methods are not shown or explained in detail in order not to obscure the understanding of the present description. The figures show:

[0071] Figure 1: a schematic flow diagram of a method for operating a universal data transport system according to one aspect of the present invention;

[0072] Figure 2: an exemplary network based on defined

[0073] Functional units of the proposed system arrangement according to a further aspect of the present invention; and

[0074] Figure 3: the proposed data transport system according to another

[0075] aspect of the present invention.

[0076] Some of the figures present parameters which are familiar to the person skilled in the art in their English terminology and which are used as parameters and therefore cannot be translated.

[0077] Figure 1 shows a schematic flow diagram of a method for operating a universal data transport system for vehicle architectures, comprising dividing 100 at least one physical data channel into a plurality of virtual data channels; reading 101 of user data in a transmitter of the data transport system; adding 102 description data to the user data according to a target data format to create at least one data set; transmitting 103 the at least one data set by means of the virtual data channels from the transmitter to a receiver based on static addressing; and receiving 104 the at least one data set in the receiver and reading the user data for use therein.

[0078] Figure 2 shows different network nodes of the proposed data transport arrangement or data transport system. The network nodes can act as transmitters and / or receivers and can also act as data sources or data sinks. Furthermore, the left component shows inputs and an output for streaming data, i.e., continuous data, and burst data, i.e., discontinuous data. Furthermore, a

[0079] The direction of communication is shown, which can be dual simplex or bidirectional. The network nodes shown can be combined, as shown in Figure 3, but can also be used in a different arrangement or topology, thus creating the proposed data transport system.

[0080] This allows us to define a function family that, in simplified terms, consists of three functional units. These functional units can be described as follows:

[0081] 1 . A pure gateway (G) (also called transceiver) that can pack / unpack stream and / or burst data

[0082] 2. A pure router (R) or mxn crossbar (m,ne N) that can route data in any direction.

[0083] 3. An mxn gateway router (G / R) (m,ne N) that can route data in any direction and can pack / unpack stream and / or burst data.

[0084] Any other combinations are possible based on the concept described above. The functional units shown are intended to provide insight into the flexibility of the architecture. Figure 3 shows the proposed data transport arrangement or data transport system, which is operated according to the proposed method. The components from Figure 2 are particularly advantageous here. The data transport system is used in automobiles.

[0085] CPII1 and CPII2 can communicate bidirectionally via PCI Express using the respective 1x2 gateway routers (1) and (2), and can also address gateway (3) via PCI Express, also bidirectionally. Simultaneously, CPU1 can feed video data via HDMI and DisplayPort into the 1x2 gateway router (1), which can then be output as DSI to gateway (4) and eDisplayPort to gateway (7). Furthermore, CPU2 can operate gateways (4) and (6) as well as router (5) using the bidirectional MH interface on the 1x2 gateway router (2). Router (5) shows an unused serial interface which can be used, for example, for future network expansions.

[0086] The network shown is intended as an example. Networks of any complexity, with all conceivable application interfaces in all directions, are conceivable.

[0087] The gateways, routers and gateway-routers presented here make completely new network and data architectures possible in the vehicle, as there is a uniform transport layer that can route and bundle all existing interfaces in any direction to any gateway / router / gateway-router, even with the lowest latency requirements and optimal use of bandwidth, and can also perform “interface bridging” if required (provided the data type is the same, e.g. in the case of video data, a DisplayPort input at one gateway to a DSI output at another gateway).

[0088] In addition, connectors, cables, weight, electrical energy and ultimately costs can be saved in the vehicle through bundling.

[0089] The susceptibility to errors in such a bundled network is significantly lower than in many individual point-to-point connections. Furthermore, bundling also greatly simplifies error diagnosis in a network like the one presented here.

[0090] The network shown in this setup can be easily expanded by using a router / gateway router, thus opening up new possibilities for model updates and equipment options, for example.

[0091] Sublayer of the physical medium

[0092] Purpose and function

[0093] The lower layer of the physical medium is electrically connected to the physical transmission medium. The primary transmission medium is a differential 100-ohm cable. Optical transmission media can also be considered as an option.

[0094] The physical transmission format depends on the data rate and is either NRZ for low data rates or PAM4 for high data rates.

[0095] This layer implements the serialization of M-bit parallel line-coded data (M = raw serializer bit width) on the transmit side and the recovery of the serial clock and bit-serial data, as well as the deserialization to M-bit parallel line-coded words on the receive side. Serial data transmission is based on the "embedded clock" concept, meaning no time is transmitted, only serial data, which, due to line coding, enables time recovery.

[0096] The core clock frequency is primarily determined by the SERDES's "raw bit width" M. For example, at 30 GBps and a raw bit width of M=128, this results in a core clock frequency of 234.375 MHz.

[0097] Interface to the physical medium

[0098] In the direction of the transmission medium, the physical medium sublayer, according to one aspect of the present invention, implements two unidirectional, differential, bit-serial 100-ohm interfaces: a transmit and a receive interface. The physical medium consists entirely of a differential forward and a differential return line. This arrangement also enables the optional operation of optical media without extensive matching circuitry.

[0099] For the physical medium, the focus is on twisted-pair cables, as the insertion loss of coaxial cables is equal to that of twisted-pair cables at higher frequencies. Considering the 6 dB attenuation of single-ended transmission compared to differential transmission, coaxial cables have absolutely no advantage.

[0100] The maximum cable length depends on the data rate (and the cable diameter).

[0101] In the transmit direction, according to one aspect of the present invention, a bit time system for serializing the data is generated using a PLL. The data / symbols are transmitted using this bit time. This bit time forms the basis for the synchronous Tx clock system. The Tx data path is directed in the opposite direction to this time system. (Target synchronous)

[0102] In the receive direction, the time used to serialize the data is recovered from the received serial data stream using a CDR. This time forms the basis for the synchronous Rx clock system. The Rx data path is directed in the same direction as this clock system (source synchronous).

[0103] A stated that the core clock frequency is primarily determined by the SERDES raw bit width (M). For example, at 30 GBps and a raw bit width of M=128, this results in a core clock frequency of 234.375 MHz. Since SERDES technologies can vary, M will also vary. Consequently, the cell format and the cell data interfaces between the different layers must support flexible raw SERDES bit widths, or the cell format must be decoupled from the cell row data width.

[0104] Transmission sublayer

[0105] Purpose and function According to one aspect of the present invention, the transmission sublayer generates N-bit wide transmission frames (see: 7.

[0106] Transmission frame and cell format) in the transmit direction the M-bit wide symbols of the line code for the SERDES raw interface and generates the N-bit wide transmit frames again from the M-bit symbols of the SERDES raw interface in the receive direction.

[0107] The main function of the transmission sublayer is to assemble the transmission frames from the cells in the transmission direction and vice versa, in the reception direction, to decompose the transmission frames into cells.

[0108] To adapt the data rate of the cell stream to the data rate of the serial transmission, this layer can insert idle cells in the transmit direction (from the application interface to the serializer) according to one aspect of the present invention. Cell availability depends on the total bandwidth requirements of all application interfaces. Thus, according to one aspect of the present invention, the cells do not form a continuous cell stream, as the cells are processed (collected, assembled, and merged) using a core clock that limits the maximum bandwidth of the SERDES.

[0109] In the receive direction (from the deserializer to the application interfaces), empty cells are discarded. Cells are extracted from the serial frame. Since, similar to the transmit direction, the cell data rate is lower than the bandwidth relative to the core time, these cells are forwarded with a data validity signal.

[0110] This layer handles the flow of cells. In addition to generating cell headers and CRCs, or extracting data from the cells with CRC checks, a so-called add-drop multiplexer function is implemented here.

[0111] This means that in the transmit direction, the cells are collected from the various service functions, assigned a VP identifier, and a cell header and footer are generated, collected by the peer-to-peer interface, and then multiplexed into a common cell stream (add function). In the receive direction, according to one aspect of the present invention, the cell stream is distributed from the input device in the receive direction to the various service functions and the peer-to-peer interface according to the VP identifier. The data for the service functions is unpacked and CRC-checked (drop function). All cells whose VP identifier does not belong to a service function are forwarded to the peer-to-peer interface (forward function).

[0112] Application Adaptation Layer(s) AAL

[0113] The application adaptation sublayer is the "topmost" layer in the three-tier model. Here, the cell-based virtual data paths are converted back into physical data paths. These are connected to the various application interfaces via generic service interfaces for stream or burst data.

[0114] The rules for splitting and reassembling packets and streams into cells are called application adaptation sublayers.

[0115] The two most important are Stream Data, for example, for video and audio data, and Burst Data, for almost all types of packets. Which AAL is used in each case is not encoded in the cell. Instead, it is configured between two endpoints or agreed upon based on a virtual circuit.

[0116] Segmentation & Re-Assembly Sublayer (with AAL function)

[0117] Purpose and function

[0118] In the transmit direction, the segmentation layer together with the application-specific AAL function according to one aspect of the present invention implements the starting point for the cell-based virtual data paths.

[0119] In the receive direction, the reassembly layer, together with the application-specific AAL function, implements the endpoint for the cell-based virtual data paths. The main task of the segmentation & reassembly sublayer (together with the application-specific AAL function) is to enable the format conversion (bit-wide) of streamed or burst data with any bit width into the N-bit cell row data format.

[0120] The interfaces between the Stream Data or Burst Data functions and the Segmentation & Reassembly sublayer have the bit width of the cell rows (N). The Stream Data or Burst Data AAL functions combine clock-domain traversal and bit-wide conversion of the data from the application interface to the N bits of the cell rows. The cell row payload is already formatted so that the cell header and footer fit into the first and last cell rows.

[0121] The Segmentation & Reassembly sublayer fundamentally controls the data flow through the AAL functions. It evaluates the availability of application data and (possibly) the acceptance of cell data (backpressure to be defined).

[0122] According to one aspect of the present invention, the cells offer the possibility of transmitting payload information data in addition to payload data. (See 7.1 Cell Format). The payload data is used, for example, to generate frame signals for video or audio in the case of stream data and to generate packets, transactions, or bursts in the case of burst data.

[0123] Binding frame signals to stream data with the payload information

[0124] The basic idea of ​​connecting frame signals to the data stream is to define a significant anchor point (or several anchor points) in the frame timing and to transmit this (or these) using the payload info bits in such a way that a clear synchronization of the data stream and the frame signals is possible. Ideally, this is achieved by placing a fixed point of the data stream at a fixed point in the marked data line. To restore the frame timing, a free-running timing generator is used, which can generate the entire timing independently. The timing is then adapted to the data stream by evaluating the payload info bits and adapting the timing to the defined position in the data line.

[0125] Stream data (continuous data stream)

[0126] The Stream Data interface combines the transition from the application clock domain to the cell clock domain and the conversion of the bit width of data from the application interface to the N bits of the cell rows. The cell row payload is preformatted so that the cell footer and header fit into the first and last cell rows.

[0127] Streaming data is (usually) source-synchronous. Clock domain crossing of the data path from the application clock domain to the cell clock domain is performed.

[0128] A data buffer is provided in the transmit direction, into which the source-synchronous data is written at the application clock. The input device in the transmit direction retrieves the data from this buffer as needed to perform the data format conversion into the N-bit-wide rows of cells. Frame signals (e.g., Hsync, Vsync, DE) are encoded in payload info bits, allowing reconstruction of the frame signals on the receiver side.

[0129] In the receive direction, the cell data is written from the output device into a data buffer. The frame signals are reconstructed based on the payload info bits. The application clock on the transmit side is regenerated, for example, using buffer fill level and clock synthesis.

[0130] If data encryption is required (HDCP), the cell data is encrypted or decrypted in this function.

[0131] Due to the different types of stream data, such as audio and video with and without encryption, there may be different implementations of this basic function (e.g., VStream In / Out; AStream In / Out; EncVStream In / Out). Burst data (discontinuous data stream)

[0132] The burst data interface combines the transfer from the application clock domain to the cell clock domain and the conversion of the burst data bit width from the application interface to the N bits of the cell rows. The cell row payload is preformatted so that the cell footer and header fit into the first and last cell rows.

[0133] Burst data is (usually) synchronous to an external clock and has different identification signals for direction and data type (Address / Data / ByteEnable).

[0134] This data is usually accompanied by control lines to implement a specific protocol.

[0135] A data buffer is provided in the transmit direction, into which the burst data is written with the interface clock. The input device in the transmit direction retrieves the data from this buffer as needed to perform the data format conversion into the N-bit-wide rows of cells.

[0136] In the receive direction, the cell data is written into a data buffer by the output device. The interface control signals are reconstructed based on the payload info bits.

[0137] The payload info bits are used to generate the control signals of the application-specific interfaces or to synchronize the protocol state machines in the application-specific interfaces.

[0138] Due to the different interfaces that provide burst-like data (SPI, I2C, MH), there may be different implementations of this basic function (e.g.: SPIBurst, l2CBurst, MIIBurst).

[0139] Accordingly, there will be (slightly) different stream in / out interfaces, but their structure should be the same. Cell format / frame format

[0140] According to one aspect of the present invention, the cell consists of a header with a fixed bit length, a payload area with 4 selectable bit lengths and a footer again with a fixed bit length.

[0141] The cell structure is a sequence of bits as follows:

[0142] • A 7-bit virtual path identifier (VP), which represents a unique address of the virtual path.

[0143] • A 3-bit sequence number (SN) that consecutively numbers the cells in their order.

[0144] • A 2-bit Cell Type (CT) identifier that specifies the length of the payload data.

[0145] • A 3-bit Payload Information (PI) that contains additional information about the payload. This can also be used to synchronize payload data with frame data or control data.

[0146] • A 10-bit CRC polynomial (HCRC) for error protection of the header information. The polynomial has a Hamming distance of 5 up to a bit sequence of 21 bits (P=0x2B9).

[0147] • The payload (PL) area has a length of 187, 411, 635, or 859 bits, depending on the CT value. The shortest payload is chosen so that it is still larger than the largest supported (video) streaming bus width. (Should simplify the mapping of stream data to the cell payload.)

[0148] • Finally, a 12-bit CRC polynomial (PCRC) for error protection of the payload data. The polynomial has a Hamming distance of 4 for bit sequences up to 2035 bits (P=0x8F3).

[0149] Transmission Frame Format: According to one aspect of the present invention, the transmission frame consists of a sequence of M-bit words. The frame begins with an M-bit "comma" word from a defined sequence of comma words for frame alignment. This is followed by K cells. The cells consist of 2, 4, 6, or 8 N-bit words containing the header, payload, and footer. These N-bit words are encoded into M-bit symbols (line encoding).

[0150] This format is chosen to allow processing of cell data at reasonable time frequencies, provided that the serializer / deserializer always processes a block of M bits.

Claims

Patent claims 1. Method for operating a universal data transport system for vehicle architectures, comprising: - a subdivision (100) of at least one physical data channel into a plurality of virtual data channels; - a reading (101 ) of user data in a transmitter of the data transport system; - adding (102) descriptive data to the payload data according to a target data format to create at least one data record; - a transmission (103) of the at least one data record via the virtual data channels from the sender to a receiver using static addressing; and - a receiving (104) of the at least one data record in the receiver and reading the user data for its use.

2. Method according to claim 1, characterized in that the number of virtual data channels per physical data channel is a maximum of 128.

3. Method according to claim 1 or 2, characterized in that a bandwidth is located separately for each virtual data channel.

4. Method according to one of the preceding claims, characterized in that all virtual data channels are operated at least temporarily in a duplex mode.

5. Method according to one of the preceding claims, characterized in that a different number of physical and / or virtual data channels are available for each communication direction.

6. Method according to one of the preceding claims, characterized in that the virtual data channels are set up exclusively for continuous or discontinuous data sets.

7. Method according to one of the preceding claims, characterized in that virtual data channels are prioritized independently of one another.

8. Method according to one of the preceding claims, characterized in that network nodes of the data transport system alternately act as sender or receiver.

9. Method according to one of the preceding claims, characterized in that the user data is output in the receiver by means of an output unit and / or the receiver represents a data sink.

10. Method according to one of the preceding claims, characterized in that the method uses exclusively volatile storage media.

11. Method according to one of the preceding claims, characterized in that bidirectional routing is carried out within the transmitter.

12. Method according to one of the preceding claims, characterized in that the user data is available as video data and / or audio data.

13. Data transport system for vehicle architectures, comprising: - a subdivision unit set up to subdivide (100) at least one physical data channel into a plurality of virtual data channels; - an interface unit set up for reading (101) user data in a transmitter of the data transport system; - a packaging unit set up to add (102) descriptive data to the payload according to a target data format to create at least one data record; - a transmitting interface unit set up for transmitting (103) the at least one data record via the virtual data channels from the sender to a receiver using static addressing; and - a receiving interface unit set up for receiving (104) the at least one data record in the receiver and reading the user data for its use.

14. Computer program product comprising instructions that, when executed by at least one computer, cause it to perform the steps of the method according to any one of claims 1 to 12.

15. Computer-readable storage medium comprising instructions that, when executed by at least one computer, cause it to perform the steps of the method according to any one of claims 1 to 12.

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