Transmission / reception device of user station and method of communication in serial bus system

Abstract

A transmitting / receiving device for a master subscriber station or a responder subscriber station of a serial bus system. The transmitting / receiving device comprises: a transmitting module for transmitting a digital transmission signal of a frame of a message as a differential signal to a bus of a bus system; the receiving module is used for receiving the differential signal from the bus, generating a digital receiving signal according to the differential signal and forwarding the digital receiving signal to the communication control equipment so as to evaluate the digital receiving signal according to a preset frame; an operating mode switching module for switching the transmitting module and the receiving module to a first operating mode between messages on the bus, or for switching the transmitting module and the receiving module to a second or third operating mode when a message is transmitted or received, when the operation mode switching module receives the edge from the bus, the sending module and the receiving module are switched from the first operation mode to a third operation mode for receiving messages from the bus.

Description

TECHNICAL FIELD

[0001] The present application relates to a transmitting / receiving device for a master user station or a responder user station of a serial bus system, and to a method for communication in a serial bus system. BACKGROUND

[0002] Bus systems are used in many technical fields for communication between technical devices, such as sensors and control devices.

[0003] It is known to use Classical CAN and / or CAN FD for communication between devices in vehicles and / or other technical devices, both of which are standardized in the international standard ISO 11898-1:2015. With CAN FD, communication on the bus at, for example, 2 Mbit / s or 5 Mbit / s is possible. Here, 64 bytes can be transmitted for each message on the bus.

[0004] Furthermore, CAN XL can also be used, which is compatible with CAN FD and is specified in ISO / DIS 11898-1:2024. With CAN XL, communication on the bus at a bit rate of up to 20 Mbit / s and a data volume of up to 2048 bytes per message is possible.

[0005] User stations of such a bus system are also referred to as nodes. Such user stations have a microcontroller, which, in the case of CAN XL, supports all functions specified in the aforementioned standards for Classical CAN and / or CAN FD and / or CAN XL.

[0006] CAN XL offers the great advantage that data can be exchanged between user stations of the bus system at significantly faster speeds than with Classical CAN or CAN FD. However, the requirements for the communication device for performing communication with CAN XL and thus the costs are higher than for a communication device designed only for Classical CAN and / or CAN FD.

[0007] The cost aspect is particularly disadvantageous for those user stations that only perform very simple functions. Such user stations are, for example, indicator lights, in particular light-emitting diodes (LEDs), which are to be switched on or off under the control of the microcontroller of another user station and / or should change color as required. Another example is a sensor, which should provide its collected data to the microcontroller of another user station from time to time.

[0008] It is therefore desirable to still be able to utilize the advantages of CAN XL at lower communication costs than hitherto. However, this is not easy to achieve due to the complexity of CAN XL. SUMMARY

[0009] It is therefore the task of the present application to provide a transmitting / receiving device for a master or responder subscriber station of a serial bus system and a method for communicating in a serial bus system which solves the problems described above. In particular, a transmitting / receiving device for a master or responder subscriber station of a serial bus system and a method for communicating in a serial bus system should be provided in which communication in the serial bus system can take place with high error robustness, at a higher bit rate than hitherto and with a high net data transmission rate, while the costs are lower than hitherto.

[0010] This task is solved by a transmitting / receiving device for a master or responder subscriber station of a serial bus system having the features of claim 1. The transmitting / receiving device has a transmitting module for transmitting a digital transmit signal based on a frame of a message to be transmitted via a bus of the bus system as a differential signal onto the bus, a receiving module for receiving the differential signal from the bus and generating a digital receive signal from the differential signal received from the bus and forwarding the digital receive signal to a communication control device for evaluation in accordance with a predetermined frame of the message from the bus, and a run mode switching module for switching the transmitting module and the receiving module into a first run mode between messages on the bus or into a second or third run mode when transmitting or receiving a message, wherein the run mode switching module is designed to switch the transmitting module and the receiving module from the first run mode into the third run mode to receive a message from the bus when the run mode switching module receives an edge from the bus.

[0011] The described transmitting / receiving device for a subscriber station (master or responder) can be designed as a CAN XL transmitting / receiving device (transceiver) or a CAN SIC XL transmitting / receiving device (transceiver) with a significantly reduced functional scope and / or a significantly lower complexity of the circuit design. This is achieved by communication with CAN XL-light, since the explicit bus state is no longer used in this bus system, which requires significantly higher circuit complexity for handling compared to the other bus states. The described communication can also be referred to as extended CAN XL light or CAN XL light Extended.

[0012] Abandoning the dominant bus state also allows for 100% impedance symmetry between the bus signal terminals. In a CAN bus system, these terminals can be referred to as CANH and CANL, used for the differential bus signals CAN_H and CAN_L. Since the dominant bus state forces asymmetry at the CAN_H and CAN_L terminals, which reduces the transmittable bit rate and may increase electromagnetic emissions from the user station, the described user station (responder) design offers significant advantages in signal quality. Furthermore, eliminating the dominant bus state saves semiconductor area (especially silicon area) and results in identical circuitry at the bus terminals for both L0 and L1 bus states. This provides advantages in improving the user station's immunity to interference and reducing radiation.

[0013] A significant advantage of the described transmitting / receiving devices for master or responder user stations is the substantial reduction in system-level cost. This cost reduction is due to the fact that, at least in the responder user station, a significantly reduced functional range of CAN XL transmitting / receiving devices (transceivers) or CAN SIC XL transmitting / receiving devices (transceivers) can be used. Another reason for the cost reduction is that a high-precision clock is not required in the responder user station, as arbitration is not needed during communication on the bus, and therefore arbitration is neither supported nor performed by the responder user station. In arbitration, user stations on the bus negotiate bit-by-bit using an identifier (ID) in the arbitration field to determine which user station wishes to send the message with the highest priority and thus gains exclusive access to the bus system 1 for transmission in the subsequent data phase, as is known in CAN bus systems, for example, from ISO / DIS 11898-1:2024. The accuracy of this clock can be at least one-fifth of the CAN XL clock.

[0014] Another reason for the significant cost reduction is that a protocol controller with a significantly reduced function range can be used in the responder user station, which can save more than 50%.

[0015] The reduced cost of the modified CAN XL transceiver or the modified CAN SIC XL transceiver is due to the smaller semiconductor area required and lower circuit design complexity. As mentioned earlier, this semiconductor is, in particular, silicon.

[0016] The described design of the transmitting / receiving device for a master controller user station or a responder user station enables the integration of the responder onto a single ASIC (Application-Specific Integrated Circuit) at a favorable cost using hybrid semiconductor processes (e.g., bipolar transistors, CMOS transistors, and DMOS transistors (BCD technology)). Upon receiving a transmission request from the master controller, the responder user station (responder) transmits its functional information (e.g., sensor values) to the master controller user station (master controller) using CAN XL messages.

[0017] The described transmitting / receiving device for a master user station or a responder user station can be used for extended CAN XL light communication between the master user station and the responder user station, achieving a bit rate higher than that currently possible with CAN FD. In particular, the bit rate exceeds 10 Mbit / s, and especially reaches up to 20 Mbit / s. Therefore, using the described communication between the master user station and the responder user station, a significantly higher bit rate can be achieved than CAN-FD-Light (which can only reach 2 Mbit / s or 5 Mbit / s).

[0018] Furthermore, compared to CAN FD light, the resulting master user station and responder user station can transmit significantly larger data packets per message via the bus. This is because the described responder user station is designed to transmit 2048 bytes or more (specifically 4096 bytes) per message via the bus, while CAN FD light only allows 64 bytes.

[0019] Another additional advantage is that the described transmitting / receiving equipment for master controller user stations or responder user stations can be implemented as a combined transceiver product that supports both CAN XL light extended and other standards for transmitting differential signals, especially 10BASE-T1S. This increases application possibilities and thus provides users with greater flexibility.

[0020] In summary, the described transmitting / receiving device helps to make bus systems more cost-effective at data rates up to 20 Mbit / s and data packets in messages of approximately 2 kByte or more, while still enabling robust or reliable communication using differential signaling.

[0021] Other advantageous designs of the transmitting / receiving device are described in the dependent claims.

[0022] It is possible to design the operating mode switching module such that when the operating mode switching module receives a predetermined signaling from the communication control device, it switches the sending module and the receiving module from the third operating mode to the first operating mode.

[0023] The transmitting / receiving device can be designed such that, in a first operating mode, a first physical layer is used to generate only a first bus state on the bus, and in a second and third operating mode, a second physical layer different from the first physical layer is used to generate second and third bus states, respectively, as symmetrical bus states, for differential signals on the bus.

[0024] It is possible that in the first operating mode, only one bus state of the differential signal on the bus is different from each of the symmetrical bus states of the differential signal on the bus in the other two operating modes, and the transmitting / receiving device is designed for the symmetrical bus states in the other two operating modes.

[0025] The transmitting / receiving device can be designed to: enable a predetermined receiving threshold when switching from a first operating mode to a third operating mode, for generating a digital receiving signal based on the differential signal received by the bus; and disable the predetermined receiving threshold when switching from the third operating mode to the first operating mode.

[0026] The aforementioned transmitting / receiving device may be part of a responder user station for a serial bus system. The responder user station also has a communication control device for controlling communication between the user station and the master user station of the bus system, and for evaluating at least one signal received from the bus based on a predetermined frame of messages from the bus of the bus system. The communication control device is designed to signal to the transmitting / receiving device, at each bit of the predetermined frame, which operating mode the transmitting / receiving device should switch to.

[0027] The communication control device can be designed to send messages to the master user station via the bus only when the master user station requests the responder user station by sending a request.

[0028] The responder user station may also have an operating mode signaling module for indicating with a signal which of three different operating modes the transmitting / receiving device should switch to. This operating mode signaling module may be designed to: indicate the switching of operating mode at the beginning of a message in the transmission signal when the transmitting / receiving device should switch to an operating mode for sending messages to the bus; and to indicate the switching of operating mode at the beginning of a message when the transmitting / receiving device is switched to an operating mode for receiving messages from the bus.

[0029] It is possible that the responder user station is designed to use CAN XL frames in XLFF format as the predefined frames.

[0030] The aforementioned transmitting / receiving device may be part of a master user station for a serial bus system. The master user station also has a communication control device for controlling communication between the user station and the responder user station of the bus system, and for evaluating at least one signal received from the bus based on a predetermined frame of messages from the bus of the bus system. The communication control device is designed to signal to the transmitting / receiving device, at each bit of the predetermined frame, which operating mode the transmitting / receiving device should switch to in the operating mode.

[0031] The communication control equipment of the master controller user station can be designed to request the responder user station to send messages to the master controller user station via the bus by sending requests.

[0032] The master controller user station may also have an operating mode signaling module for signaling which of three different operating modes the transmitting / receiving device should switch to. This operating mode signaling module can be designed to: indicate the switching of operating mode at the beginning of a message in the transmission signal when the transmitting / receiving device should switch to an operating mode for sending messages to the bus; and to indicate the switching of operating mode at the beginning of a message when the transmitting / receiving device is switched to an operating mode for receiving messages from the bus. The described master controller user station can support more than one frame format. Therefore, in the master controller user station, synchronization functions can be enabled or disabled, for example, as described above, by setting the values ​​of configuration bits. If synchronization (resynchronization to the bit stream seen at terminal RXD) is disabled, the master controller user station no longer supports arbitration and can therefore only be used as a master.

[0033] If the master user station does not need to be compatible with the current ISO 11898-1, it can be designed to be more cost-effective than a user station that is ISO 11898-1 compliant. This is because arbitration is not required in communication between the master and responders on the bus, and therefore is unnecessary. However, it is possible for the master user station to also support arbitration, thus enabling communication with other user stations on the bus according to CAN CC, CAN FD, CAN XL, and CAN FD / XL standards. For arbitration, the master user station has either a low-tolerance clock or a high-precision clock. In contrast, the responder user station can have a high clock tolerance because it allows for a large (e.g., 90%) of the clock tolerance.

[0034] The aforementioned master controller user station and at least one of the aforementioned responder user stations may be part of a bus system having a bus and at least two user stations interconnected via the bus, enabling the user stations to communicate serially with each other, wherein each of the at least two user stations also has a transmitting / receiving device for transmitting signals to the bus of the bus system and / or receiving signals from the bus of the bus system.

[0035] The above-described task is also solved by the method for communication in a serial bus system according to claim 14. This method utilizes the aforementioned master user station and the aforementioned responder user station.

[0036] This method offers the same advantages as those described earlier for user stations.

[0037] In this method, it is possible that, unlike the CAN XL user station, the master user station and the responder user station do not perform bit monitoring when sending messages; the master user station does not send an ACK bit when it correctly receives a message; the responder user station does not send an ACK bit when it correctly receives a message; the master user station and the responder user station do not perform error signaling; the master user station and the responder user station do not use overload frames; the master user station and the responder user station do not perform automatic retransmission; and the master user station and the responder user station do not perform automatic shutdown of the responder user station when a predetermined number of communication errors are detected. Attached Figure Description

[0038] Other possible implementations of the invention include combinations of features or implementations not explicitly mentioned in the foregoing or the following description of the embodiments. Those skilled in the art will also add individual aspects as improvements or supplements to the corresponding basic forms of the invention.

[0039] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments.

[0040] Figure 1 A simplified block diagram of the bus system according to the first embodiment is shown; Figure 2 The format of a CAN XL frame conforming to the ISO / DIS11898-1:2023 standard is shown for messages that can be sent by a user station of the bus system according to the first embodiment; Figure 3 A simplified schematic block diagram of a first user station (master) of a bus system according to a first embodiment is shown; Figure 4The time variation curves of digital transmission signals during bus system operation are shown when the first user station and at least one second user station are connected to the same bus of the bus system and when communication is carried out on the bus using the CAN XL standard; Figure 5 This demonstrates when the first user station uses the CAN XL or CAN XL light standard to... Figure 4 The time variation curves of the bus signals CAN_H and CAN_L at the first user station when the transmit signal is sent to the bus; Figure 6 It shows the result of Figure 5 The time variation curve of the differential voltage VDIFF of the bus signals CAN_H and CAN_L generated by the signal; Figure 7 It shows the first or second user station based on the data received from the bus. Figure 4 The time-varying curve of the digital received signal generated by the transmitted signal; Figure 8 The time variation curve of the digital transmission signal at the first user station during bus system operation is shown in the communication using CAN XL light Extended at the first user station according to the first embodiment; Figure 9 The time variation curves of bus signals CAN_H and CAN_L at the first user station according to the first embodiment are shown when the first user station uses CAN XL light Extended; Figure 10 It shows that due to Figure 9 The time-varying curves of the differential voltage VDIFF of the bus signals CAN_H and CAN_L generated on the bus; and Figure 11 A simplified schematic block diagram of a second user station (responder) of a bus system according to a first embodiment is shown.

[0041] In these figures, unless otherwise specified, the same or functionally equivalent elements are given the same reference numerals. Detailed Implementation

[0042] Figure 1 Bus system 1 is shown as an example, which is designed primarily for the CAN XL bus system and / or its variants, as described below. Bus system 1 can be used in vehicles, particularly motor vehicles, aircraft, etc., or in hospitals, etc.

[0043] exist Figure 1In the bus system 1, there is a bus 40, and the master controller user station 100 and multiple responder user stations 101, 102, 103, ..., 10N are connected to the bus. N is a natural number greater than or equal to 1.

[0044] One to N responder user stations 101, 102, 103, ..., 10N are connected to bus 40. Bus 40 may have a first bus core line 41 ( Figure 3 ) and the second bus core wire 42 ( Figure 3 The bus core wire is in Figure 1 Not shown in the diagram. These bus cores, also known as CAN_H and CAN_L, are used for electrical signal transmission after a dominant level is coupled into the input, or a recessive level or other level is generated for signals in the transmit state.

[0045] The main controller user station 100 is, for example, a control device for a motor vehicle or other technical facility, which will be described in more detail below. The responder user stations 101, 102, 103, ..., 10N may have, for example, at least one sensor, at least one display device, at least one actuator, or at least one signal generator of a motor vehicle or other technical facility, which will be described in more detail below.

[0046] As shown in Figure 1, the master controller user station 100 has a communication control device 11, a transmitting / receiving device 12, a synchronization module 15, an operating mode signaling module 18, and an operating mode switching module 19. Each of the responder user stations 101, 102, 103, ..., 10N has a communication control device 21, a transmitting / receiving device 22, a synchronization module 25, an operating mode signaling module 28, and an operating mode switching module 29.

[0047] The transmitting / receiving devices 12 and 22 of user stations 100, ..., 10N are all directly connected to bus 40, although this... Figure 1 Not shown in the image.

[0048] The master controller user station 100 is designed to create messages 45 in signal form. Alternatively, the master controller user station 100 may also be designed to create messages 46 for CAN FD or other CAN types. In the following example, the master controller user station 100 is designed to send only messages 45 in signal form to one of the user stations 101, ..., 10N via bus 40.

[0049] In the following examples, Figure 1User stations 101, ..., 10N are designed to create messages 45 in signal form and send them to the master user station 100 via bus 40. Message 45 can be transmitted serially between user station 100 and one of user stations 101 to 10N.

[0050] Communication control devices 11 and 21 are used to control communication between user station 100 and one of user stations 101, ..., 10N via bus 40. Communication control devices 11 and 21 create a transmission signal TxD when needed, which will be discussed in detail below. Figure 4 A more detailed description will follow. Furthermore, communication control devices 11 and 21 also read or decode the received signal RxD, which will be discussed in conjunction with the following description. Figure 7 To provide a more detailed description.

[0051] The communication control device 11 can be implemented, at least in part, as a conventional CAN-XL controller or a conventional CAN-XL-light controller conforming to ISO / DIS 11898-1:2024. Therefore, depending on the implementation, the communication control device 11 can support the transmission and / or reception of seven different frame formats: four classic CAN frame formats, two CAN-FD frame formats with 11-bit or 29-bit identifiers, and one CAN XL frame format. The CAN FD frame format, in particular, is known from ISO 11898-1:2015 and will not be described in detail here. The aforementioned frame formats are divided into two communication phases: an arbitration phase and a data phase, which will be described in more detail below.

[0052] Figure 1 The communication control device 11 is implemented to enable it to communicate with user stations 101, ..., 101N using CAN-XL messages 45. Modules 18 and 19 are used for sending and receiving CAN-XL messages 45. Additionally, corresponding synchronization modules 15 and 25 may optionally be used. CAN-XL messages 45 are constructed based on the CAN-XL format, which... Figure 2 A more detailed description will follow. Synchronization modules 15 and 25 are only required at bit rates greater than 1 Mbit / s. The operating mode signaling module 18 is used to signal to the transmitting / receiving device 12 when it should or should switch its operating mode during the transmission of CAN-XL message 45. The operating mode switching module 19 is used to switch the operating mode of the transmitting / receiving device 12 as needed during the transmission or reception of message 45, as will be described in more detail below.

[0053] The communication control device 21 is implemented at least partially as a CAN-XL-light controller. For this purpose, a synchronization module 25 is provided, designed to be compatible with the synchronization module 15. The communication control device 21 creates messages 45, such as those with... Figure 2The system receives CAN XL messages from the user station 100 and is designed to read messages from the user station 100. The operating mode signaling module 28 is used to signal to the transmitting / receiving device 22 when sending CAN-XL messages 45, indicating that the transmitting / receiving device 12 should or should switch its operating mode. The operating mode switching module 29 is used to switch the operating mode of the transmitting / receiving device 12 as needed when sending or receiving messages 45, as will be described in more detail below.

[0054] The communication described below in bus system 1 can also be referred to as CAN XL Light Extended.

[0055] In order to communicate with one of the user stations 101, ..., 10N, user station 100 (the master controller) sends a transmission request to the desired user station 101, ..., 10N via bus 40. This transmission request is made by sending a transmission request based on... Figure 2 The message 45 of the CAN-XL frame 450 shown is used. Only when user station 100 requests responder user stations 101, ..., 10N by sending a request will responder user stations 101, ..., 10N send a message via bus 40 to master user station 100 based on... Figure 2 Message 45 of the CAN-XL frame. The request to send is encoded in frame 450 sent by user station 100 (master), for example in Figure 2 The data fields shown below will be described in the following text.

[0056] In both the CAN XL Light bus access method and the CAN XL Light Extended method, only user station 100 (the master controller) initiates communication with the responder user station. To do this, user station 100 (the master controller) sends a message according to... Figure 2 Message 45 in frame 450. After message 45 ends, user station 100 (master controller) can provide a certain time window for at least one of the N responders, in which one of the N responder user stations 101, ..., 10N can send message 45 in response to the transmission request. User station 100 (master controller) can provide a certain time window in which up to N user stations 101, ..., 10N (responders) can successively send message 45. Correspondingly, the signals of user stations 101, ..., 10N (responders) and the data of user stations 101, ..., 10N (responders) are transmitted on bus 40 as a channel within a predetermined time period or time slot. For example, for this purpose, each of the user stations 101, ..., 10N (responders) is designed to identify and use a time slot intended for it.

[0057] Therefore, user station 100 functions as a command issuer / querier relative to user stations 101, ..., 10N, while each of the aforementioned user stations 101, ..., 10N functions as a responder. Both the CAN XL Light bus access method and the bus access method according to CAN XL Light Extended are hybrids of polling and time-division multiplexing methods. Time-division multiplexing is also known as TDM (Time Division Multiplex) or TDMA (Time Division Multiple Access).

[0058] In the following text, user station 100 can also be referred to as CAN-XL-light-Extended-Commander, while user stations 101, ..., 10N can be referred to as CAN-XL-light-Extended-Responder.

[0059] Figure 2 A frame 450 for message 45 in CAN XL frame format (also known as XLFF format) is shown, which can be created by one of user stations 101, ..., 10N or user station 100. However, user stations 100, ..., 10N are not limited to... Figure 2 Frame 450 can be used, or other frames can be used to communicate on bus 40.

[0060] according to Figure 2 The CAN XL frame 450 can be provided by the user station (master controller) 100 or the communication control device 11, i.e., encoded in a digital transmit signal TxD, to the associated transmit / receive device 12 for transmission on the bus 40 to another user station of the bus system 1. Alternatively, the CAN XL frame 450 can be provided by the user station (responder) 101, ..., 10N or its communication control device 21, i.e., encoded in a digital transmit signal TxD, to the associated transmit / receive device 22 for transmission on the bus 40.

[0061] Frame 450 is divided into two communication phases, referred to as Arbitration Phase 451 (first communication phase) and Data Phase 452 (second communication phase) in CAN, CAN FD, and CAN XL, respectively. Frame 450 begins and ends at Arbitration Phase 451, even if no arbitration is performed during communication on bus 40, as will be described in more detail below.

[0062] In CAN XL Light Extended, user stations 100, ..., 10N use symmetrical '1' and '0' levels in both the first communication phase (arbitration phase) 451 and the second communication phase (data phase) 452 for... Figure 1 Frame 450 is transmitted on bus 40 instead of using recessive and dominant levels as in the arbitration phase 451 of CAN FD and CAN XL, as previously described.

[0063] Figure 2 Frame 450 begins with the SOF bit and includes an Arbitration field (453), a Control field (454) (which includes an ADS field for switching between communication phases 451 and 452), a Data field (455), a Checksum field (456) (CRC field), an Acknowledge field (457) (ACK = Acknowledge), and an End of Frame (EOF) field. The CAN-XL format is specified in ISO / DIS 11898-2:2024.

[0064] Bits in the first communication phase (arbitration phase) 451 of frame 450 may have a longer bit time than bits in the second communication phase (data phase) 452. Switching from a bit with the bit time of the first communication phase (arbitration phase) 451 to a bit with the bit time of the second communication phase (data phase) 452 occurs in the ADH bit at the beginning of control field 454.

[0065] In CAN XL, CAN XL light, and CAN XL light Extended, Figure 2 The bit indicated by a thick line at the bottom of the middle line is sent as dominant or "L0" (especially L = low or "0") in frame 450. Figure 2 Bits indicated by thick lines at the top of the frame are transmitted as recessive or "L1" (specifically H = High or "1") in frame 450. Figure 2 These bits, indicated by thick lines, have predetermined fixed or specified values ​​in frame 450.

[0066] Arbitration field 453 in arbitration phase 451 is set in CAN XL with the help of an identifier (ID) Figure 2 Frame 450 performs arbitration. However, as mentioned earlier, in CAN XL light and CAN XL light Extended, user stations 100, ..., 10N do not perform arbitration.

[0067] In this embodiment, a bit rate of less than or equal to 20 Mbit / s can be used in the first communication phase (arbitration phase) 451. However, the same bit rate can also be used in phases 451 and 452. The latter is the primary application case in CAN XL lightExtended, allowing for fast transmission speeds of up to 20 Mbit / s throughout the frame.

[0068] According to Figure 2, in data phase 452, in addition to a portion of the control field 454 of the transmitted frame 450, the payload data of the CAN-XL frame 450 or message 45 in data field 455 and the checksum field 456 are also transmitted. In this embodiment, a data bit rate that can have a value of up to 20 Mbit / s is used in data phase 452.

[0069] According to Figure 2, frame 450 contains the ADS and DAS fields. In CAN XL, these two fields are used to switch the bit rate and to switch the transmitting / receiving device 12 (transceiver) from operating mode SIC to operating mode FAST_TX or FAST_RX, or from FAST operating mode back to operating mode SIC. In CAN XL light Extended, these fields only function for switching the bit rate, applicable when a slower bit rate is selected in arbitration phase 451 than in data phase 452.

[0070] Typically, two different bit stuffing rules are applied when generating frame 450. CAN FD or CAN FD is applied up to the FDF bit in the arbitration field 453. Figure 2 The dynamic bit stuffing rule in frame 450 causes a padding bit to be inserted after five consecutive identical bits. In data phase 452, up to the FCP field, a fixed bit stuffing rule applies, causing a fixed number of padding bits to be inserted after a fixed number of bits, with the padding bit being the opposite of the previous bit.

[0071] In this embodiment, where the master controller and responder only understand CAN XL frames, the res bit (which is represented by the XLF bit in frame 450), known from CAN FD, no longer has the function of switching from CAN FD format to CAN XL format. However, the frame formats of CAN FD and CAN XL are the same up to the res bit or XLF bit. In CAN XL light Extended, the XLF bit is sent as 1 (i.e., L1) to identify frame 450 as a CAN XL frame. For CAN FD frames, the communication control device 11 sets this bit to 0 or L (=low=LOW), i.e., as a dominant res bit. If user station 100 is at least partially a conventional CAN XL user station, then user station 100 also supports CAN FD. Conversely, user stations 100, ..., 10N are designed for CAN XL light Extended and only support frame 450 (CAN XL format) during transmission and reception.

[0072] In frame 450, the XLF bit is followed by the resXL bit, which is a dominant bit for future use. For frame 450 in CAN XL lightExtended, resXL must be sent as 0 (i.e., L0).

[0073] In frame 450, the resXL bit is followed by the ADS (Arbitration Data Switch) sequence in the ADS field, which has been described above in conjunction with the DAS field.

[0074] Subsequent fields up to and including data field 455 will not be described in further detail here. Data field 455 can have up to 2048 bytes or more. The length of data field 455 is encoded in bits 0 to 10 of the DLC field.

[0075] In frame 450, following the data field 455 is a checksum field 456 containing the frame checksum (FCRC) and FCP fields. In this case, FCP stands for Frame Check Pattern. The FCP field consists of 4 bits, specifically bit sequence 1100. The receiver (receiving node) of frame 450 uses the FCP field to check whether it is bit-synchronized with the transmitted data stream. Furthermore, the receiving node synchronizes to the falling edge of the FCP field.

[0076] The FCP field is followed by the Frame Completion field 457. The Frame Completion field 457 consists of two fields: the DAS field mentioned above and below, and an acknowledgment field or ACK field with at least ACK bits and ACK-Dlm bits.

[0077] The DAS field has been described above.

[0078] As previously described, in CAN XL light Extended, in order to transmit message 45 between user stations 100, ..., 10N, the physical layer switches from the recessive bus state to the physical layer used for L0 and L1 bus states. In CAN XL light Extended, the switching between the operating modes of transmitting / receiving devices 12 and 22 occurs at the beginning and end of a frame. Communication control devices 11 and 21 use pulse width modulation (PWM) with respect to the transmit signal TxD to signal the switching to their associated transmitting / receiving devices 12 and 22.

[0079] Following bit AH1 are bit AL1 (logic 0) and bit AH2 (logic 1). Using bits DAH and AH1, it can be ensured that all user stations 100, 101 to 10N see a recessive level significantly longer than the arbitration bit time before the edge of bit AL1 (logic 0). This guarantees reliable synchronization of user stations in bus system 1.

[0080] In the frame completion field 457, the sequence of DAS fields is followed by the acknowledgment field (ACK). The acknowledgment field contains bits used to acknowledge or deny successful reception of frame 450. In CAN XL light Extended, receiving user stations 100, ..., 10N do not send a transmit acknowledgment (ACK bit) with a logic 0 value, which typically indicates successful reception. Instead, receiving user stations always send the ACK bit as a logic 1.

[0081] In frame 450, after the frame completion field 457 is the frame end field (EOF = End of Frame), as in a CAN FD conforming to ISO 11898-1:2015.

[0082] In frame 450, after the End of Frame (EOF) field is the Inter Frame Space (IFS), which... Figure 2 Not shown in the diagram. The inter-frame spacing (IFS) is designed in CAN FD according to ISO 11898-1:2015. The inter-frame spacing (IFS) has at least 3 bits.

[0083] For CAN XL, the following applies: Unlike CAN FD, the identifier ID for frame 450 in CAN XL is called "Priority ID".

[0084] Unlike CAN FD, CAN XL can transmit the RRS bit as either logic 0 or logic 1. In CAN FD, the RRS bit is always transmitted as logic 0.

[0085] Figure 3 The basic structure of a user station 100 is shown, which includes a communication control device 11, a transmitting / receiving device 12, and a synchronization module 15 that is part of the communication control device 11. Furthermore, an operating mode signaling module 18, which is at least partially part of the communication control device 11, is also shown. Additionally, an operating mode switching module 19, which is at least partially part of the transmitting / receiving device 12, is also shown.

[0086] According to Figure 3, in addition to the communication control device 11 and the transmitting / receiving device 12, the user station 100 (main controller) also has a microcontroller 13 and a system ASIC 16 (ASIC = Application-Specific Integrated Circuit), with the communication control device 11 disposed on the microcontroller. Alternatively, the system ASIC 16 may be a system base chip (SBC) that integrates multiple functions required by the electronic components of the user station 100. The system ASIC 16 particularly has an application 161, which can be designed as a computer program (App) or software. This application is a technical application 161. Application 161 is, for example, any application in a vehicle. This application is particularly such as a windshield washer system and / or a driver assistance system. For example, a windshield washer system uses data from a rain sensor and / or a windshield speed sensor and / or a speed sensor and / or a light sensor to control the movement of at least one windshield wiper (actuator), and / or can turn on or off a warning light (actuator). However, this application is not limited to a windshield washer system or any part thereof.

[0087] In the system ASIC 16, in addition to the transmitting / receiving device 12, a power supply device 17 is also built in, which provides power to the transmitting / receiving device 12. The power supply device 17 typically provides a 5V CAN_Supply (VCC) voltage. However, the power supply device 17 can provide other voltages with other values ​​as needed. Alternatively, the power supply device 17 can be designed as a current source.

[0088] In order to communicate with one of user stations 101, ..., 10N, the communication control device 11 creates frame 450, in which... Figure 2Bit rate switching can be performed in the ADS and DAS fields, as previously described, and / or such frames 450 can be evaluated. For this purpose, a conventional CAN-XL communication control device conforming to ISO / DIS11898-1:2024 can be used for device 11, which has the aforementioned or described additional functions. Thus, a data bit rate, particularly up to 20 Mbit / s, can be achieved in the data phase 452. When the communication control device 11 is used as a CAN-XL-Light-Extended-Commander, bit rate switching can be enabled or disabled. Disabling it means that the user sets the same bit rate for the first communication phase (arbitration phase) 451 and the second communication phase (data phase) 452. In this case, the bit rate can also reach a maximum of 20 Mbit / s.

[0089] According to Figure 3, the synchronization module 15 has a synchronization block 151, optionally a configuration block 152, optionally an evaluation block 153, and a switching block 154. In particular, the value of at least one synchronization configuration bit 1521 can be stored in the optional configuration block 152. The synchronization block 151 may be a bit timing control unit (BTL) of the communication control device 11.

[0090] Synchronization module 15, especially evaluation block 153 and switching block 154, can be implemented at least partially as software.

[0091] Synchronization block 151 has the synchronization function described in ISO / DIS11898-2:2024. However, this synchronization function can be switched as needed, as will be described in more detail below.

[0092] The transmitting / receiving device 12 has a transmitting module 121 and a receiving module 122. Although the transmitting / receiving device 12 is always referred to below, the receiving module 122 may alternatively be disposed in a separate device external to the transmitting module 121. The transmitting module 121 and the receiving module 122 can be constructed like a conventional CAN-SIC-XL transmitting / receiving device 12, with the additional functions described above or below. The transmitting module 121 may, in particular, have at least one operational amplifier and / or transistor. The receiving module 122 may, in particular, have at least one operational amplifier and / or transistor.

[0093] Transmitting / receiving device 12 is connected to bus 40, specifically its first bus line 41 for CAN_H and second bus line 42 for CAN_L. Voltage is supplied to power supply device 17 via at least one terminal 43 to provide power to the first and second bus lines 41, 42, particularly the CAN-Supply voltage. Connection to ground or CAN_GND is made via terminal 44. The first and second bus lines 41, 42 are terminated with terminating resistor 49.

[0094] In the transmitting / receiving device 12, the first and second bus cores 41 and 42 are connected not only to the transmitting module 121 (also referred to as the transmitter) but also to the receiving module 122 (also referred to as the receiver), although for simplicity, this connection is... Figure 3 Not shown in the image.

[0095] During the operation of bus system 1, Figure 3 The transmitting module 121 can transmit the signal TxD (e.g., from the communication control device 11) Figure 4 The transmit signal TxD is serially converted into corresponding signals CAN_H and CAN_L for CAN XL or its variants for bus cores 41 and 42, and these signals are transmitted to bus 40 at the terminals of CAN_H and CAN_L.

[0096] Communication control equipment 11 will Figure 4 The transmitted signal TxD (if communication can be made via XL light in bus system 1) or Figure 8 The transmit signal TxD1 (if communication is possible in bus system 1 according to XL light Extended) is transmitted serially to the transmit module 121 via the TXD terminal over time t, such as... Figure 3 As shown. (As illustrated) Figure 4 As shown in the example, the transmitted signal TxD has voltage states H (High = high) and L (Low = low), each voltage state having a corresponding voltage U. In Figure 4 On the right side, signal TxD is pulse-width modulated using the first symbol PWM1 and the second symbol PWM2 in the transmitted signal TXD. In this case, the second symbol PWM2 is different from the first PWM symbol PWM2, as shown below. Figure 4 As shown.

[0097] Based on the example in Figure 5, user station 100 can be designed to communicate via CAN XL light, i.e., during the arbitration phase 451... Figure 2Frame 450 generates signals CAN_H and CAN_L, which have dominant and recessive bus levels 401 and 402 according to the first physical layer 451_P, as known from CAN XL. Furthermore, user station 100 can be designed to communicate according to CAN XLlight, i.e., during the data phase 452... Figure 2 Frame 450 generates bus levels L0 and L1 according to the second physical layer 452_P, as is known from CAN XL.

[0098] Figure 5 on the left shows that in CAN XL light, user station 100 can send signals CAN_H and CAN_L with a first time t_bt1 to bus 40 at time t during the first communication phase 451. Signals CAN_H and CAN_L are serial signals and alternately have at least one dominant state 401, in which VCAN_H = 3.5V and VCAN_L = 1.5V at a power supply voltage of VCC = 5V, or alternately have at least one recessive state 402, in which VCAN_H = VCAN_L = 2.5V. When TXD = 0 or LOW (LOW = low) ( Figure 5 In stage 451, the dominant state 401 (dom) is driven when the transmitted signal TXD is NRZ encoded. When TXD=1 or HI (high)... Figure 5 In stage 451, a recessive state 402 (rec) is generated or formed when the transmitted signal TXD is NRZ encoded.

[0099] As shown on the right side of Figure 5, in the transmitted signal TXD, state L0 is driven when pulse width modulation (PWM encoding) of the transmitted signal TXD is performed for the first PWM symbol PWM1 (VCAN_H=3.0V, VCAN_L=2.0V when VCC=5V). State L1 is driven when pulse width modulation (PWM encoding) of the transmitted signal TXD is performed for the second PWM symbol PWM2 (VCAN_H=2.0V, VCAN_L=3.0V when VCC=5V). The bit time t_bt2 of states L0 and L1 is shorter than the bit time t_bt1.

[0100] Figure 6The differential signal VDIFF = CAN_H – CAN_L formed on bus 40 is shown. Transmitting / receiving devices 12 and 22 can identify individual bits of the VDIFF signal with bit time t_bt1 during arbitration phase 451 using, for example, a receive threshold T1 of 0.7V (which is within the range TH_T1, as known from CAN XL). Using, for example, an optional receive threshold T2 of -0.3V (which can be enabled only during arbitration phase 451 and is within the range TH_T2), transmitting / receiving devices 12 and 22 can identify whether bus levels L0 and L1 have been transmitted on bus 40. Using the optional receive threshold T2, user station 100, switched to the operating mode of arbitration phase 451, can identify whether bus levels L0 and L1 of data phase 452 have appeared on bus 40. During the communication phase (data phase) 452, the transmitting / receiving devices 12 and 22 use, for example, a receiving threshold T3 of 0.0V (which is within the range of TH_T3, as known from CAN XL) to identify the individual bits of the VDIFF signal.

[0101] Figure 4 The sequence of states H and L of the transmitted signal TxD, and the resulting state H and L. Figure 5 The states 401 and 402 of the CAN_H and CAN_L signals, and the resulting... Figure 6 The voltage VDIFF variation curve is only used to illustrate the function of user station 100. The data state sequences of bus states 401 and 402 can be selected as needed.

[0102] The receiving module 122 receives the CAN_H and CAN_L signals from the bus 40 (which are in... Figure 5 (as shown) or Figure 6 The differential voltage VDIFF forms the received signal RxD. In order to generate... Figure 7 The digital received signal RxD is received by the receiving module 122 using the aforementioned receiving thresholds T1, T2, and T3. Figure 7 This shows that the received signal RxD has no propagation time delay. The receiving module 122 forwards the received signal RxD to the associated communication control device 11, such as... Figure 3 As shown.

[0103] The reception thresholds T1 and T2 are used to identify whether bus 40 is idle when user station 12 newly accesses communication at bus 40 and attempts to integrate into the communication of bus 40.

[0104] If user stations 100, 101, ..., 10N with CAN XL light Extended capability use the operating mode switching module 19 to switch the operating mode of their transmitting / receiving devices 12 and 22, then the sender of frame 450 generates a signal based on...Figure 8 The transmitted signal TxD1 enables the transmission of signals based on... Figure 2 Message 45 of frame 450 is generated on bus 40. Figure 9 and Figure 10 The signal, not Figure 5 and Figure 6 The signal. For simplicity, it is not shown in the figure. Figure 5 to Figure 7 The signal compared to Figure 4 The propagation time delay of the transmitted signal. Similarly, for simplicity, it is not shown in the figure. Figure 9 and Figure 10 The signal compared to Figure 8 The propagation time delay of the transmitted signal.

[0105] Therefore, user stations 100, ..., 10N are designed to communicate according to CAN XL light Extended, as described below for user station 100 (master) and as an example for user station 101 (responder).

[0106] Table 1: Communication status of user stations 100, ..., 10N in CAN XL light Extended.

[0107] Therefore, symmetrical bus states L0 and L1 exist only in the operating mode FAST_TX. Here, each user station 101, ..., 10N transmits at high impedance (REC) in operating mode FAST_RX, but each user station 101, ..., 10N adjusts its receive threshold to 0V in operating mode FAST_RX in order to be able to decode bus states L0 and L1.

[0108] like Figure 9 As shown, when there is no communication or no load on bus 40, transmitting / receiving devices 12 and 22 use the first operating mode SIC of the CAN XLSIC user station. Here, transmitting / receiving devices 12 and 22 use physical layer 4510_P, which only generates recessive state 402 (Rec) on bus 40. Furthermore, transmitting / receiving devices 12 and 22, as transmitters, use the second physical layer 452_P for the entire frame 450 to transmit the signal TxD (… Figure 8 The signals are sent to bus 40 as CAN_H and CAN_L signals over time t. For physical layer 452_P, there are two operating modes, namely FAST_TX and FAST_RX mentioned above.

[0109] When communicating in bus system 1 according to CAN XL light Extended, transmitting / receiving devices 12 and 22 use the receive threshold T1, and optionally also the receive threshold T2, when there is no communication, i.e., in operating mode SIC. As the receiver of frame 450, i.e., in operating mode FAST_RX, transmitting / receiving devices 12 and 22 use only the third receive threshold T3 at approximately 0.0V. Therefore, the third receive threshold T3 at approximately 0.0V is off when there is no communication on bus 40. By disabling the third receive threshold T3, the recessive state 402 (Rec) on bus 40 is prevented from causing an erroneous state determination on bus 40.

[0110] Although not shown in Figures 9 and 10, the bits of the CAN_H and CAN_L signals in communication phase 452 of frame 450 can be transmitted at least temporarily, for example, at a bit time t_bt2 as described above. Therefore, in the case of CAN XL, the CAN_H and CAN_L signals in communication phase 452 of frame 450 differ from the conventional CAN_H signal in classic CAN at least in terms of bus states L0 and L1, and optionally also by a faster bit rate.

[0111] Each user station 100, 101, ..., 10N can send and / or receive. In the example below, it is only assumed that user stations 101, ..., 10N are the receivers of the currently sent frame 450.

[0112] Assuming user station 100 (master controller) sends frame 450 to bus 450, then communication control device 11, especially operating mode signaling module 18, receives... Figure 8 The transmit signal TxD1 begins with the SOF bit and signals its transmit / receive device 12 using the pulse width modulation symbol P. Symbol P can be defined as PWM symbol PWM1 or PWM symbol PWM2. Alternatively, other PWM symbols can be used. Symbol P signals to the transmit-receive device 12 that it must switch from the operating mode SIC, which generates bus state 402 (rec), to the operating mode FAST_TX in order to serially transmit the subsequent bits of frame 450 onto bus 40.

[0113] Therefore, the transmitting-receiving device 12 switches the physical layer 4510_P, where the bus state 402 (rec) is generated, to physical layer 452_P.

[0114] As shown in Figure 9, the sending module 121 of the user station 100, acting as the sender, then switches to the second operating mode (FAST_TX) starting from the SOF bit and according to... Figure 8The transmitted signal TxD1 sequentially generates states L0 or L1 for the CAN_H and CAN_L signals on bus 40 via physical layer 452_P. The CAN_H and CAN_L signals on bus 40 are delayed for a time that the transmitting module 121 needs to decode. Figure 8 The transmit signal TxD1 is sent and transmitted to bus 40. Figure 10 shows the differential signal VDIFF generated on bus 40.

[0115] For CAN XL light Extended, the transmitting module 121 of user station 100 also uses the SOF bit as the PWM symbol to generate bus state L0, such as... Figure 8 and Figure 9 As shown in the diagram, the PWM symbol is sent to the transmitting / receiving device 12. This PWM symbol is decoded by the transmitting / receiving device 12, specifically its operating mode decoding module 19. Based on the PWM symbol for bus state L0, the transmitting / receiving device 12 enables the operating mode FAST_TX. Prior to this, the transmitting / receiving device 12 was in operating mode SIC, in which it always transmits the implicit bus state. Because decoding of the PWM symbol is always only possible at the end of the PWM symbol, the transmitting / receiving device 12 transmits the bus states L0 / L1 with a delay of one PWM symbol length. Therefore, in Figure 9 In the middle, SOF bit ratio Figure 8 The value is shifted to the right by the length of one PWM symbol.

[0116] Therefore, in this example, user station 100 (the master controller) is the sender of frame 450. Therefore, user station 101 is the receiver of frame 450, not the sender. The same applies to responder user stations 102, ..., 10N. Therefore, the transmitting / receiving devices 22 of user stations 101, ..., 10N receive frame 450 according to... Figure 10 When the bus state L0 (alternative L1) of the signal is detected, since one of the receiving thresholds T1 (alternative T2) is detected, it will be used to switch the physical layer of the communication phase 452, that is, switch from the physical layer 4510_P of the first operating mode SIC to the physical layer 452_P of the third operating mode FAST_RX of the transmitting / receiving device 22.

[0117] At the end of frame 450, the following applies. At the end of frame 450, communication control device 11, more specifically its operating mode signaling module 18, sets the PWM encoding and stops transmitting PWM symbols. If transmitting / receiving device 12 detects that the PWM encoding has stopped on its terminal TXD used for transmitting signal TxD1, then transmitting / receiving device 12 will switch from transmitting signals using physical layer 452_P (operating mode FAST_TX) to operating mode SIC using physical layer 4510_P. Transmitting / receiving device 12 is designed to activate only the receive threshold T1 (alternatively T2) in operating mode SIC. Therefore, the receive threshold T3 = approximately 0.0V is disabled or turned off.

[0118] At the end of frame 450, communication control device 21, more specifically its operating mode signaling module 28, sets the PWM encoding and stops sending PWM symbols. If transmitting / receiving device 22 detects that PWM encoding has stopped, it switches its receive operating mode (FAST_RX) to the first operating mode (SIC). This switch means that transmitting / receiving device 22 disables or turns off its receive threshold T3 = approximately 0.0V and activates T2.

[0119] Upon receiving a corresponding signal from bus 40, each transmitting / receiving device 12 generates an associated receive signal RxD, such as... Figure 7 As shown and described above.

[0120] Therefore, user station 100 is designed like a conventional CAN-XL user station with the aforementioned additional functions. The user ensures that user station 100 acts as the CAN XL Light Extended master, and user stations 101, ..., 10N act as CAN XL Light Extended responders, based on a request-based (polling) principle, by designing the data fields and / or selecting the identifiers (IDs) of user station 100 (master) and user stations 101, ..., 10N. Thus, user station 100 (master) can send message 45 to each of user stations 101, ..., 10N (responders). User station 100 (master) encodes in message 45 whether the responder should respond. A responder is only allowed to send a message if there has been a prior request, and a certain time window is used for this, within which a maximum of N user stations 101, ..., 10N (responders) can successively send message 45.

[0121] Alternatively, user station 100 (master controller) can be configured as follows.

[0122] During the operation of bus system 1, user station 100 (master controller), more specifically communication control device 11, performs bus monitoring. According to ISO 11898-1:2015, user station 100, and especially communication control device 11, at sample point t_A (Sample-Point), measures itself based on frame 450 and transmitted signal TxD (…). Figure 5 or Figure 8 The bits sent are based on the received signal RxD ( Figure 7 The bits observed on bus 40 are compared. Differences, except in the arbitration and ACK bits, are considered errors.

[0123] However, when user station 100 (master controller) is the sender of message 45, user station 100 (master controller), more precisely, communication control device 11, disables bus monitoring during short bit times t_bt1 and t_bt2, according to a pre-configured software setting. Short bit rates may occur during arbitration phase 451 and / or data phase 452. Such short bit times occur when the bit rate exceeds 1 Mbit / s, during which the so-called loop delay of user station 100 (CAN node) reaches half a bit time t_bt1, t_bt2, or longer. The so-called loop delay refers to the time elapsed until user station 100 can internally treat the bits transmitted via terminal TXD of the transmit signal TxD as received signal RxD.

[0124] Furthermore, during the operation of the bus system 1, the user station 100 (master controller), or more precisely the communication control device 11, uses the synchronization block 151 to perform a synchronization function on all frames 450 received by the user station 100 (master controller) from one of the responders 101, ..., 10N.

[0125] Synchronization block 151 observes the edges from recessive to dominant or vice versa, i.e. Figure 6 , Figure 7 or Figure 9 , Figure 10 The transition between states 401, 402, or 402, 401. Synchronization block 151 synchronizes the bit time t_bt1 based on the observed edge. Figure 5 and Figure 6The position of the sampling point t_A (Sample-Point) within the frame is determined. This allows the receiver to synchronize with the sender of frame 450. If the edge ideally occurs at the beginning of bit times t_bt1, t_bt2, synchronization is not required because edge transitions may occur at the beginning of bit times. If the edge occurs between the beginning of bit times t_bt1, t_bt2 and the sampling point t_A, a so-called "late edge" exists. This leads to synchronization, extending the current bit times t_bt1, t_bt2 during synchronization. If the edge occurs between the sampling point t_A (Sample-Point) and the end of bit times t_bt1, t_bt2, a so-called "early edge" exists. This leads to synchronization, shortening the current bit times t_bt1, t_bt2 during synchronization.

[0126] According to ISO 11898-1:2015, the sender of frame 450 also performs synchronization. However, there is a limitation: the user station 100 transmitting dominant bits will not synchronize to the late edges. This is because the sender sees all its transmitted bits as late due to loop delay. Therefore, synchronizing to these late edges transmitted by the user station itself would prolong these bits and distort the bit rate. Allowing synchronization to the early edges can stabilize CAN arbitration at the beginning of frame 450. This is especially necessary when arbitration occurs. Arbitration does not occur in CAN XL light extended.

[0127] The synchronization function is described in more detail in ISO 11898-1:2015.

[0128] However, the synchronization function of synchronization block 151 can be switched as needed using synchronization module 15, as described below.

[0129] Evaluation block 153 is designed to evaluate the synchronization configuration bit 1521 in configuration block 152. Synchronization configuration bit 1521 is set when user station 100 (master controller), more specifically communication control device 11, should transmit frame 450 using the bit time t_bt1 of the first communication phase 451 of CAN XL (this bit time corresponds to a bit rate greater than a predetermined bit rate). The predetermined bit rate is in particular greater than 1 Mbit / s.

[0130] If the evaluation by evaluation block 153 determines that the synchronization configuration bit 1521 is set, then evaluation block 153 checks whether user station 100 (master), or more precisely, communication control device 11, should (currently) act as the sender, i.e., whether it should send frame 450 to the responder on bus 40. The synchronization configuration bit 1521 is set, for example, along with the bit rate configuration, and can be implemented via software or hardwired. Then, during the operation of bus system 1, configuration bit 1521 remains constant.

[0131] If the evaluation by evaluation block 153 determines that user station 100 (master), or more precisely, communication control device 11, should act as the sender and transmit frame 450 to the responder on bus 40, then evaluation block 151 instructs switching block 154 to disable synchronization block 151. Therefore, for all bits of frame 450 that user station 100, as master, intends to send on bus 40, up to the last bit of the end-of-flight field, switching block 154 disables synchronization block 151 and thus disables its aforementioned synchronization function.

[0132] By disabling synchronization block 151, the sender is prevented from synchronizing to an edge that it sees not within the transmitted bit time but within one of the subsequent bit times. Since arbitration is impossible (because arbitration is no longer possible at bit rates exceeding 1 Mbit / s t_b1), synchronization can be disabled.

[0133] After the last bit of the End of Frame (EOF) field of the transmitted frame, Figure 4 Switching block 154 restarts synchronization block 151 and thus enables its aforementioned synchronization function.

[0134] Furthermore, in user station 100 (master controller), the necessity to send acknowledgment responses (ACK bit or ACK-response) for message 45 sent by the responders (user stations 101, ..., 10N) can be disabled. Similarly, in user station 100 (master controller), the necessity to receive acknowledgment responses (ACK bit or ACK-response) for message 45 sent by it to the responders (user stations 101, ..., 10N) can also be disabled.

[0135] According to Figure 11, in addition to communication control device 21 and transmitting / receiving device 22, responder user station 101 also has a simple control mechanism (FSM) or optionally a microcontroller 23 and a system ASIC 26 (ASIC = Application-Specific Integrated Circuit). The communication control device 21 is configured with the microcontroller. Alternatively, the system ASIC can be a system base chip (SBC) on which multiple functions required for the electronic components of user station 101 are integrated. The system ASIC 26 specifically has an application 261, which can be designed as a computer program (App). This application is technology application 261.

[0136] Application 261 is, for example, used for the control of sensors, signal generators, actuators, etc., and this control is provided by application 161 of the main controller user station 100. Figure 3 (Control, or should provide data for application 161)

[0137] The responder has limited or no local computing power and can perform simple functions such as turning LEDs on / off and controlling their color, as previously described. The responder only sends Frame 450 when requested by the master controller via a transmission request. Therefore, the responder CAN user station (responder) sends its functional information (such as sensor values) to the master controller CAN user station (master controller) via CAN XL messages based on the master controller's transmission request.

[0138] As shown in Figure 11, in addition to the transmitting / receiving device 22, the system ASIC 26 also includes a built-in power supply device 27, which provides power to the transmitting / receiving device 22. The power supply device 27 typically provides a 5V voltage (CAN_Supply). However, the power supply device 27 can also provide other voltages with different values ​​as needed. Alternatively, the power supply device 27 can be designed as a current source.

[0139] Communication control device 21 creates frame 450, in which bit rate switching or bit rate transformation can be performed (such as regarding...). Figure 2 The frame 450 is evaluated based on the frame received from the master user station 100. The communication control device 21 acts as a CAN-XL-Light-Extended-Responder. Devices 21 and 22 can only send such a frame 450 onto the bus 40 upon request (polling) from the master user station 100.

[0140] As mentioned above, the operation mode signaling module 28 uses the PWM symbol P in the terminal TXD or TxD signal to indicate to the transmitting module 221 that when it is necessary to send message 45, it should switch from the recessive bus state to the bus level L0 or L1 according to the state L, H or 0, 1 in the TxD signal.

[0141] Furthermore, when the receive threshold T1 (approximately +0.6V) is exceeded, the operation mode switching module 29 enables the receive threshold T3 in the receive module 222. The operation mode switching module 29 then disables the receive threshold T3 again, particularly in the DAS field or at the end of frame 450 (after EOF (7 bits), as previously described. The decision to disable the receive threshold T3 is recognized when PWM encoding at terminal TXD has not occurred.

[0142] During the operation of bus system 1, when responder user station 101 is currently a receiver, responder user station 101 performs the following method. However, each of the user stations 100, ..., 10N (master and responder) is designed in the same way and acts as a receiver in the same way as described below.

[0143] An edge on bus 40—where the receive threshold T1 (approximately 0.7V or approximately 0.6V) is exceeded—puts the transmitting / receiving device 22 into operating mode FAST_RX. In operating mode FAST_RX, operating mode switching module 29 enables the receive threshold T3 (approximately 0.0V) in receiving module 222.

[0144] The transmitting / receiving device 22 transmits the bus signal of the transmit signal TxD, which corresponds to logic 0 due to the start bit SOF, to the terminal RXD, and further transmits it to the communication control device 21.

[0145] Based on the 1 to 0 edges of the SOF bits on terminal RXD, the communication control device 21 recognizes that it should receive certain content.

[0146] Therefore, the communication control device 21 instructs the operating mode signaling module 29 to signal the transmitting / receiving device 22 (transceiver) to switch to operating mode FAST_RX. This signaling ensures that the transmitting / receiving device 22 (transceiver) remains in operating mode FAST_RX as long as the signaling continues.

[0147] At the end of frame 450 (which is known to communication control device 21), communication control device 21 disables the operating mode signaling. Therefore, transmitting / receiving device 22 (transceiver) switches to or enters operating mode SIC.

[0148] In other respects, Figure 10 The sending module 221 is as described above for... Figure 3 The sending module 121 is constructed in the manner described.

[0149] Figure 10 The synchronization module 25 has a synchronization block 251, a configuration block 252, an evaluation block 253, and a switching block 254. At least one configuration bit 2521, 2522 is stored in the configuration block 252.

[0150] Synchronization module 25 can also disable synchronization of frame 450 or message 45 sent by user station 101, as mentioned above. Figure 3 As described by synchronization module 15 for frame 450. Therefore, synchronization module 25 always disables synchronization with frame 450 or message 45 sent by user station 101 at high bit rates. High bit rates are, for example, greater than 1 Mbit / s.

[0151] and Figure 3 The synchronization module 15 is different. Figure 10 The synchronization module 25 is optionally designed to disable synchronization of frames 450 or messages 45 sent to user station 101 at low bit rates, as needed in the associated responders. For this purpose, an additional configuration bit 2522 can be set, for example. Low bit rates are, for example, less than or equal to 1 Mbit / s. This disabling has little impact on communication between the master user station 100 and the corresponding responder user stations 101, ..., 10N.

[0152] Therefore, you can choose to Figure 11 The synchronization module 25 is optionally designed to disable its synchronization function with frames 450 or messages 45 sent by user station 101 at both low and high bit rates. In other words, this allows for the selection of synchronization functions. Figure 10 The synchronization module 25 is designed to disable its synchronization function for frames 450 or messages 45 sent by user station 101 regardless of the bit rate.

[0153] User stations 101, ..., 10N can forgo these synchronizations because arbitration does not occur in CAN XL Light and CAN XL LightExtended, or when communicating with the master user station 100, and ACK bits are not sent at higher bit rates.

[0154] Synchronization module 25 is otherwise constructed in the manner described above for synchronization module 15.

[0155] Therefore, synchronization modules 15 and 25 enable communication with the CAN XL Light at a bit rate greater than or equal to 1 Mbit / s.

[0156] User stations 101, ..., 10N (responders) therefore have a CAN-XL-Light protocol controller, which is additionally or alternatively designed for the aforementioned CAN XL light Extended functionality. The CAN-XL implementation of communication control device 21 is adjusted for this purpose. These adjustments aim to simplify or reduce functionality to lower resource requirements. For example, the following adjustments are the main ones.

[0157] Bit monitoring during message 45 transmission is absent or disabled in communication control device 21. This is possible because CAN XL light and CAN XL light Extended do not require arbitration and cannot send error frames. The lack of arbitration allows for the transmission of error frames based on... Figure 10The sampling point t_A (Sample Point) is further placed at the center of the bit, allowing for greater tolerance in terms of CAN clock accuracy. Furthermore, the "transmitter delay compensation" function can be optimized away or omitted, as it is only used for bit monitoring during the data phase of transmission frame 450, and bit monitoring is no longer used.

[0158] Furthermore, signaling via error frames and overload frames is absent or disabled in the communication control device 21. This is possible because direct error signaling is not required in CAN XL Light and CAN XL lightExtended.

[0159] Furthermore, communication control device 21 does not perform automatic retransmission. Since CAN XL Light and CAN XL Light Extended cannot resolve conflicts on bus 40 through arbitration, CAN-XL-Light user stations 101, ..., 10N (responders) are not allowed to automatically repeat message transmission.

[0160] Furthermore, fault constraint is omitted in communication control device 21. CAN XL, CANFD, and classic CAN (CC) specify that if a user station detects too many communication errors, the user station on the CAN bus is automatically shut down. This is to prevent a faulty user station from interfering with the communication of other user stations. Since in CAN XL Light and CAN XL lightExtended, the responder only sends Frame 450 when requested by the master controller via Frame 450, automatic node shutdown is not required.

[0161] For example, the communication control device 11 of the main controller can also be based on Figure 3 As described in the design, the communication control device 21 of the responder is also designed for high bit rates (i.e., greater than 1 Mbit / s) during the arbitration phase 451: - When device 21 correctly receives message 45, it does not send an ACK bit, and - During frame 450, it is not synchronized with the received signal RxD (which is being transmitted). Figure 7 ).

[0162] However, unlike the communication control device 11 of the master controller, the communication control device 21 of the responder is designed to only support or send and / or receive CAN frames in XLFF format (XL base frame format).

[0163] Therefore, the CAN XL light Extended responder can be optionally designed to transmit and receive only one format (XL) of frames, i.e., according to... Figure 2 Frame 450.

[0164] By limiting it to a single frame format, the implementation complexity of the CAN XL light Extended responder, especially its communication control device 21, is significantly reduced.

[0165] According to the second embodiment, the transmitting / receiving devices 12 and 22 are designed to use different methods in the aforementioned communication on the bus 40 according to CAN XL light Extended. Figure 10 Other levels of L0 and L1. Such other levels may be, for example, L0 and L1 levels according to the 10BASE-T1S standard.

[0166] Therefore, transmitting / receiving devices 12 and 22 are designed to generate differential signals CAN_H and CAN_L on bus 40, such that the differential voltage VDIFF has approximately +0.5V for bus state L0_10BASE. Furthermore, transmitting / receiving devices 12 and 22 are designed to generate differential signals CAN_H and CAN_L on bus 40, such that the differential voltage VDIFF has approximately -0.5V for bus state L1_10BASE.

[0167] For bus state Rec, the differential voltage VDIFF remains unchanged at 0.0V.

[0168] Even when using bus states L0_10BASE and L1_10BASE, it is still possible to... Figure 2 Frame 450 is used for communication on bus 40. Alternatively, any other frame format may be used.

[0169] The rest applies as described in the first embodiment.

[0170] According to the third embodiment, the communication control devices 11 and 21 are configured not to perform bit rate switching in frame 450 when CAN XL light Extended.

[0171] More precisely, the bit rate settings for communication control devices 11 and 21: 0 Mbit / s < Arbitration bit rate t_b1 = Data bit rate t_b2 <= 20 Mbit / s Make: Bit time t_bt1 = Bit time t_bt2 Therefore, if user station 100 does not require bit rate switching functionality in other aspects, the additional area of ​​the responder ASIC 26 can be saved, and possibly the area of ​​the master controller ASIC 16 can also be saved. Furthermore, clock recovery from the CAN bit stream becomes easier, thus eliminating the need for a quartz oscillator in the responder. This further reduces the cost of the responder. The quartz oscillator can also be omitted in the aforementioned embodiment.

[0172] Furthermore, not only communication control device 21 but also communication control device 11 can be designed not to perform arbitration. User station 100 (master controller) controls communication to avoid access conflicts to bus 40.

[0173] In this way, cost-effective connections can also be made between the responder and differential bus systems, especially CAN bus systems or 10BASE-T1S systems.

[0174] The rest applies as described in the first embodiment.

[0175] All the foregoing embodiments of user stations 100, 101, ..., 10N, bus system 1, and their execution methods can be used individually or in all possible combinations. In particular, features and / or modifications of all the foregoing embodiments can be combined arbitrarily. Furthermore, or alternatively, the following modifications are particularly conceivable.

[0176] In particular, the bus system 1 according to the embodiment can be a communication network in which data can be transmitted serially at two different bit rates. Here, in the bus system 1, it must be ensured that, at least for a specific time period, a user station 100, 101, ..., 10N has exclusive, conflict-free access to the shared channel.

[0177] The number and arrangement of user stations 100, 101, ..., 10N in the bus system 1 of the embodiment are arbitrary. It is possible that there are one or more user stations 100 in the bus system 1. It is also possible that there are more than one user station 100 in the bus system 1, and each user station 100 is equipped with at least one user station 101...10N, as described above.

[0178] It is conceivable that, in user station 100, module 15 is set separately from communication control device 11. It is conceivable that, in at least one of the user stations 101, ..., 10N, module 25 is set separately from communication control device 21.

[0179] It is conceivable that, in user station 100, module 18 is separately configured from communication control device 11. It is conceivable that, in at least one of the user stations 101, ..., 10N, module 28 is separately configured from communication control device 21.

[0180] It is conceivable that, in user station 100, module 19 is configured separately from transmitting / receiving device 12. It is conceivable that, in at least one of the user stations 101, ..., 10N, module 29 is configured separately from transmitting / receiving device 22.

Claims

1. A transmitting / receiving device (12; 22) of a master subscriber station (100) or of a responder subscriber station (101;...; 10N) for a serial bus system (1), having: a transmitting module (121; 221) for transmitting a digital transmit signal (TxD) based on a frame (450) of a message (45) to be transmitted via a bus (40) of the bus system (1) as a differential signal (CAN H, CAN L) onto the bus (40), a receiving module (122; 222) for receiving a differential signal (VDIFF) from the bus (40), generating a digital receive signal (RxD) from the differential signal (VDIFF) received from the bus (40), and forwarding the digital receive signal (RxD) to a communication control device (11; 21) for evaluating the digital receive signal (RxD) in accordance with a predetermined frame (450) of a message (45) from the bus (40), and a run mode switching module (19; 29) for switching the transmitting module (121; 221) and the receiving module (122; 222) into a first run mode (SIC) between messages (45) on the bus (40) or for switching the transmitting module (121; 221) and the receiving module (122; 222) into a second or third run mode (FAST TX; FAST RX) for transmitting or receiving messages (45), wherein the run mode switching module (19; 29) is designed to switch the transmitting module (121; 221) and the receiving module (122; 222) from the first run mode (SIC) into the third run mode (FAST RX) for receiving messages (45) from the bus (40) when the run mode switching module (19; 29) receives an edge from the bus (40). The run mode switching module (19; 29) is designed to switch the transmitting module (121; 221) and the receiving module (122; 222) from the third run mode (FAST RX) into the first run mode (SIC) when the run mode switching module (19; 29) receives a predetermined signaling from the communication control device (11; 21).

3. The transmitting / receiving device (12; 22) according to claim 1 or 2, the transmitting / receiving device (12; 22) being designed to use a first physical layer (4510 P) in the first run mode (SIC) for generating only a first bus state (402) on the bus (40), and the transmitting / receiving device (12; 22) being designed to use a second physical layer (4511 P) in the second run mode (FAST TX) for generating only a second bus state (401) on the bus (40), and the transmitting / receiving device (12; 22) being designed to use a third physical layer (4512 P) in the third run mode (FAST RX) for generating only a third bus state (403) on the bus (40).

2. The transmitting / receiving device (12; 22) according to claim 1, wherein ​ ​ wherein ​ wherein the transceiver device (12; 22) is designed to use a second physical layer (452_P) different from the first physical layer (4510_P) for generating second and third bus states (402) as symmetric bus states (L0, L1) for the differential signals (CAN_H, CAN_L) on the bus (40) in the second and third operating modes (FAST_TX; FAST_RX), respectively.

4. The transmitting / receiving device (12; 22) according to claim 3, wherein In the first operating mode (SIC), only one bus state (Rec) of the differential signals (CAN_H, CAN_L) on the bus (40) differs from each of the symmetric bus states (L0, L1) of the differential signals (CAN_H, CAN_L) on the bus (40), the transceiver device (22) being designed for the symmetric bus states in the other two operating modes (FAST_TX, FAST_RX).

5. The transmitting / receiving device (12; 22) according to any one of the preceding claims, wherein The transceiver device (22) is designed to switch on a predetermined reception threshold (T3) for generating a digital receive signal (RxD) from a differential signal (VDIFF) received from the bus (40) when changing from the first operating mode (SIC) to the third operating mode (FAST_RX), but to switch off the predetermined reception threshold (T3) when switching from the third operating mode (FAST_RX) to the first operating mode (SIC).

6. A responder user station (101; 102;... ; 101N) for a serial bus system (1), having a communication control device (21) for controlling communication of the user station (101; 102;... ; 101N) with a master user station (100) of the bus system (1) and evaluating at least one signal (VDIFF; RxD) received from a bus (40) of the bus system (1) in accordance with a predetermined frame (450) of a message (45) from the bus (40), and the transceiver device (22) according to any one of the preceding claims, wherein the communication control device (21) being designed to signal to the transceiver device (22) in each bit of the predetermined frame (450) which operating mode the transceiver device (22) should be switched to.

7. The responder subscriber station (101; 102;... ; 101N) according to claim 6, wherein the communication control device (21) being designed to send a message (45) to the master user station (100) via the bus (40) only when the master user station (100) requires the responder user station (101; 102;... ; 101N) by sending a request.

8. The responder user station (101; 102;... ; 101N) according to claim 6 or 7, further having an operating mode signaling module (28) for signaling which of three different operating modes (SIC, FAST_TX, FAST_RX) the transceiver device (22) is to be switched to, the communication control device (21) being designed to signal to the transceiver device (22) in each bit of the predetermined frame (450) which operating mode the transceiver device (22) should be switched to. the communication control device (21) being designed to send a message (45) to the master user station (100) via the bus (40) only when the master user station (100) requires the responder user station (101; 102;... ; 101N) by sending a request. wherein the operating mode signaling module (28) is designed to signal a switch of the operating mode (SIC) at the beginning of the message (45) in the transmission signal (TxD) when switching the transmission / reception device (22) into the operating mode (FAST_TX) for transmitting the message (45) on the bus (40), and wherein the operating mode signaling module (28) is designed to signal a switch of the operating mode (SIC) at the beginning of the message (45) when switching the transmission / reception device (22) into the operating mode (FAST_RX) for receiving the message (45) from the bus (40).

9. The responder subscriber (101; 102;... ; 101N) according to any one of claims 6 to 8, wherein The responder subscriber station (101; 102;...; 101N) is designed to use a CAN XL frame in XLFF format as the predetermined frame (450).

10. A master subscriber station (100) for a serial bus system (1), having: a communication control device (11) for controlling the communication of the subscriber station (100) with responder subscriber stations (101; 102;...; 101N) of the bus system (1) and evaluating at least one signal (VDIFF; RxD) received from a bus (40) of the bus system (1) in accordance with a predetermined frame (450) of a message (45) from the bus (40), and the transmission / reception device (12) according to any one of the preceding claims, wherein the communication control device (11) is designed to signal to the transmission / reception device (12) in each bit of the predetermined frame (450) which operating mode the transmission / reception device (12) is to be switched into.

11. The master user station (100) according to claim 10, wherein the communication control device (12) is designed to request the responder subscriber stations (101; 102;...; 101N) by means of a transmission request to transmit a message (45) to the master subscriber station (100) via the bus (40).

12. The master subscriber station (100) according to claim 10 or 11, further having: an operating mode signaling module (18) for signaling which of three different operating modes (SIC, FAST_TX, FAST_RX) the transmission / reception device (12) is to be switched into, wherein the operating mode signaling module (18) is designed to signal a switch of the operating mode (SIC) at the beginning of the message (45) in the transmission signal (TxD) when switching the transmission / reception device (12) into the operating mode (FAST_TX) for transmitting the message (45) on the bus (40), and wherein the operating mode signaling module (18) is designed to signal a switch of the operating mode (SIC) at the beginning of the message (45) when switching the transmission / reception device (12) into the operating mode (FAST_RX) for receiving the message (45) from the bus (40).

13. A bus system (1), having: a bus (40), and at least two subscriber stations (100; 101;...; 101N) which are connected to one another via the bus (40) in such a way that they can communicate serially with one another, and wherein one subscriber station is a master subscriber station (100) according to any one of claims 10 to 12 and at least one subscriber station is a responder subscriber station (101; 102;...; 101N) according to any one of claims 6 to 9.

14. A method for communication in a serial bus system (1), wherein the method is carried out with a master subscriber station (100) according to any one of claims 10 to 12 and a responder subscriber station (101; 102;...; 101N) according to any one of claims 6 to 9.

15. The method of claim 14, wherein, Unlike a CAN XL subscriber station: the master subscriber station (100) and the responder subscriber stations (101,..., 101N) do not perform bit monitoring when sending a message (45), no ACK bit is sent when the master subscriber station (100) receives a message (45) correctly, no ACK bit is sent when the responder subscriber stations (101,..., 101N) receive a message (45) correctly, the master subscriber station (100) and the responder subscriber stations (101,..., 101N) do not perform error signaling, the master subscriber station (100) and the responder subscriber stations (101,..., 101N) do not use overload frames, the master subscriber station (100) and the responder subscriber stations (101,..., 101N) do not perform automatic retransmission, and the master subscriber station (100) and the responder subscriber stations (101,..., 101N) do not perform automatic shutdown of the responder subscriber stations (101,..., 101N) when a predetermined number of communication errors is detected.

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