Transmitting / receiving device and method for selectively waking up subscriber station of bus system

Abstract

A transmission / reception apparatus for selectively waking up a subscriber station in a serial bus system and a method for selectively waking up a subscriber station in a serial bus system are provided. The transmission / reception device has: a transmission module for transmitting a transmission signal onto a bus of a bus system, the transmission signal being created for frame-based communication; the receiving module is used for receiving the analog signal from the bus and generating a digital receiving signal according to the analog signal; and a wake-up module for waking up the subscriber station after the subscriber station has entered a dormant state for energy conservation, where the wake-up module evaluates at least one wake-up condition in order to determine whether the digital received signal corresponds to a wake-up frame indicating activation of the transmit module to wake up the subscriber station, and where the wake-up module is configured to activate the transmit module to wake up the subscriber station. The wake-up module makes a determination as to whether the digital receive signal corresponds to a wake-up frame before the receive module serially forwards a data field of valid data for the frame encoded in the digital receive signal to the wake-up module.

Description

Technical Field

[0001] The invention relates to a transmitting / receiving device for selectively waking up a subscriber station of a serial bus system and a method for selectively waking up a subscriber station of a serial bus system. Background Art

[0002] Bus systems are used in many technical fields for communication between technical devices (such as sensors and control devices). In some bus systems, technical devices need to communicate with each other. If necessary, these technical devices need to be able to switch between different standards and / or rates as needed for data transmission or communication between user stations of the bus system.

[0003] At present, for the communication between devices in vehicles and / or in other technical devices, Classical CAN and / or CAN FD are used, both of which are standardized in the international standard ISO11898-1:2015. CAN XL can also be used, which is specified in CiA610-1 and is currently integrated into ISO11898-1. In this CAN bus-based communication, a frame is used to generate a transmission signal, which is divided into an arbitration phase and a data phase. In the arbitration phase, it is negotiated between the user stations of the bus system: which user station of the bus system has exclusive access to the bus in the next data phase and is then allowed to send its data to the bus. In CAN FD and in CAN XL, in the data phase, the bits of the transmission signal are generated and sent to the bus with a shorter bit time than in the arbitration phase, in other words, at a higher bit rate. With the aid of SIC and SIC XL transceivers (also called transceivers), bit rates of up to 8 Mbit / s in the case of CAN FD and up to 20 Mbit / s in the case of CAN XL can be achieved in the data phase. On the other hand, the bit rate in the arbitration phase remains at approximately 500 kbit / s in order to enable arbitration.

[0004] In order to reduce the energy consumption of systems (such as vehicles), etc., the user stations that are not currently needed on the CAN bus should enter a dormant state and be re-awakened when needed. A predetermined wake-up pattern can be used to wake up (Wake-up), and all user stations on the bus will recognize the wake-up pattern and thus re-participate in the communication on the bus. Alternatively, a wake-up signal is sent by the management user station, and the wake-up signal is designed so that at least each user station of the bus can be awakened individually or selectively. Usually, a CAN send / receive device (transceiver) is used to wake up, and the CAN send / receive device recognizes this wake-up signal in the classic CAN frame. This is described in the international standard ISO 111898-2:2016. In this case, the term "wake-up signal" is understood to mean that: the "wake-up signal" comes from the management user station and is therefore a CAN frame (CANFrame). The CAN frame is recognized as a "wake-up signal" by the transceiver of the user station to be awakened. It may also be said that the transceiver recognizes the wake-up signal on the CAN bus, implements the wake-up signal and then forwards the wake-up signal to the rest of the user stations (nodes).

[0005] In a resource-efficient implementation, selective waking can be implemented using Classical CAN frames and a clock source available therefor which has a high tolerance and is therefore cost-effective.

[0006] However, problems arise when bit rates of more than 8 Mbit / s are to be used in the bus system, for which one or more transmit signals based on CAN XL frames are used. However, for such bit rates, CAN XL must be operated with SIC XL transceivers and error signaling must be deactivated for CAN XL communication. As a result, CAN XL automatically loses compatibility with CAN FD and Classic CAN. Therefore, communication on the bus can only be carried out with CAN XL. This has the disadvantage that Selective Wake-Up can no longer be used with Classic CAN frames.

[0007] It is also problematic that the use of CANXL frames for selective wake-up is very expensive compared to classic CAN frames. The reasons for this are the precise clock required for CAN XL and the significantly higher complexity of the CAN XL protocol. Summary of the invention

[0008] Therefore, the object of the present invention is to provide a transmitting / receiving device for selectively waking up a user station of a serial bus system and a method for selectively waking up a user station of a serial bus system, which solve the above-mentioned problems. In particular, a transmitting / receiving device for selectively waking up a user station of a serial bus system and a method for selectively waking up a user station of a serial bus system are provided, in which the selective waking up of each user station can be realized simply and cost-effectively for all (currently) possible bit rates even when different communication standards and bit rates are used in the arbitration and data phases.

[0009] This object is achieved by a transceiver for selectively waking up a subscriber station of a serial bus system having the features of claim 1. The transceiver has:

[0010] A sending module, for sending a sending signal as an analog signal to a bus of the bus system, the sending signal being created for communication based on a frame in the bus system;

[0011] a receiving module for receiving an analog signal from a bus of the bus system and for generating a digital receiving signal according to the analog signal received from the bus; and

[0012] A wake-up module is used to wake up the user station after the user station enters a dormant state for energy saving.

[0013] The wake-up module is designed to evaluate at least one wake-up condition in order to determine whether the digital received signal corresponds to a wake-up frame indicating activation of the transmission module to wake up the user station, and

[0014] The wake-up module is designed to make a judgment on whether the digital received signal corresponds to the wake-up frame before the receiving module serially forwards the data field for the valid data of the frame encoded in the digital received signal to the wake-up module.

[0015] The described embodiment of the transmitting / receiving device makes it possible to selectively wake up at least one subscriber station of a serial bus system using an embodiment that can be used independently of the possible bit rate in the bus system.

[0016] The described transmitting / receiving device can therefore use the same frames in a bus system at bit rates below 8 Mbit / s and at bit rates above 8 Mbit / s. Therefore, even in the case of increased bit rates, there is no need to switch the type of selective wake-up.

[0017] The selective waking up can be realized in an uncomplicated and therefore cost-effective manner because the described transmitting / receiving device does not have to be able to decode the short bits of the CAN XL data phase individually.

[0018] It is very advantageous that the costs of the described transceiver (wake-up transceiver) are kept low, even below the costs of a classic CAN wake-up frame. This is due to the fact that the complexity of the method executed by the transceiver for waking up is lower than in classic CAN. Another reason for this is that a clock source with a high tolerance, i.e. a low precision, is sufficient for the transceiver.

[0019] Thus, CANXL can be operated with SIC XL transmitters / receivers (transceivers) for high bit rates of up to 20 Mbit / s in the data phase, and in the case of CANXL, error signaling can be disabled. In this case, however, the previously described approach for cost-effective selective wake-up is available.

[0020] Overall, the bus system can therefore be operated very energy-efficiently and thus cost-effectively due to the high bit rate available in the data phase and the thereby more frequent approach for selectively putting individual subscriber stations of the bus system into a sleep state.

[0021] The described transmitting / receiving device also enables that at least two subscriber stations can be present in the bus system, which transmit messages to the bus according to different CAN standards. Thus, in the bus system, for example, in addition to the two CAN-XL subscriber stations, at least one further subscriber station can be present, which transmits messages to the bus according to another / different CAN standard.

[0022] Further advantageous embodiments of the transmitting / receiving device are described in the dependent claims.

[0023] According to one option, the at least one wake-up condition is a priority ID, which determines with what time priority the frames are allowed to be sent on the bus.

[0024] According to another option, the at least one wake-up condition is a single bit, which is arranged in the received frame immediately after the priority ID.

[0025] The received frame may be a CAN XL frame and the single bit may be the RRS bit.

[0026] According to yet another option, the wake-up module is designed to perform wake-up only when the wake-up module has evaluated that a wake-up frame has been received N times within a predetermined time period using the serially received digital reception signal, wherein N is a natural number greater than 1.

[0027] The wake-up module may have: a decoding block for decoding a received signal output by the receiving module based on a frame, the analog signal being created on the bus of the bus system according to the frame; and an evaluation block for evaluating a result output by the decoding block to determine whether the digital received signal corresponds to a wake-up frame.

[0028] The wake-up module may further comprise a configuration block for storing the at least one wake-up condition, wherein the evaluation block is designed to perform an evaluation of the evaluation block while accessing the configuration block and to generate a signal for activating an energy supply to the transmitting module when the digital received signal corresponds to a wake-up frame.

[0029] The above-mentioned transmission / reception device can be part of a user station, which also has a communication control device, which is designed to sample and evaluate the reception signal generated by the transmission / reception device according to a predetermined frame.

[0030] The communication control device can be designed to control the communication of the subscriber station with at least one further subscriber station of the bus system and to evaluate the received signal in which the bit time in the first communication phase can differ from the bit time in the second communication phase.

[0031] The communication control device can also be designed to negotiate with other subscriber stations in a first communication phase which of the subscriber stations of the bus system receives at least temporarily exclusive, conflict-free access to the bus in a subsequent second communication phase.

[0032] It is conceivable that the subscriber station is designed to send a wake-up frame to the bus of the bus system in order to selectively wake up at least one further subscriber station of the bus system after entering the sleep state.

[0033] Also conceivable is a bus system comprising: a bus; a first user station, which is designed to send a wake-up frame to the bus of the bus system, as described above; and at least one second user station, also as described above, which is connected to the first user station via the bus so that the user stations can communicate with each other serially.

[0034] The above object is also achieved by a method for selectively waking up a user station in a serial bus system according to claim 13. The method is performed using a transmitting / receiving device having a transmitting module, a receiving module and a waking up module, wherein the method comprises the following steps:

[0035] Using the transmission module, a transmission signal is transmitted as an analog signal onto a bus of the bus system, wherein the transmission signal is created for communication based on frames in the bus system;

[0036] Using the receiving module, receiving the analog signal from the bus of the bus system;

[0037] Using the receiving module, a digital receiving signal is generated according to the analog signal received from the bus;

[0038] The wake-up module is used to wake up the user station after the user station enters the sleep state for energy saving.

[0039] wherein the wake-up module evaluates at least one wake-up condition to determine whether the digital received signal corresponds to a wake-up frame indicating activation of the transmission module to wake up the user station, and

[0040] Before the receiving module serially forwards the data field for valid data of the frame encoded in the digital receiving signal to the wake-up module, the wake-up module makes a judgment as to whether the digital receiving signal corresponds to the wake-up frame.

[0041] The method offers the same advantages as those mentioned before with respect to the transmitting / receiving device.

[0042] Other possible implementations of the present invention also include combinations not explicitly mentioned of features or embodiments described above or below with respect to the embodiments. Here, those skilled in the art will also add individual aspects as improvements or supplements to the corresponding basic forms of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the accompanying drawings.

[0044] in:

[0045] Figure 1 shows a simplified block diagram of a bus system according to a first embodiment;

[0046] Figure 2 shows the format of a CAN FD frame according to the above-mentioned standard ISO 11898-1:2015 of a message which can be sent by a transmitting / receiving device of a user station of a bus system according to the first exemplary embodiment;

[0047] Figure 3 The format of a CAN XL frame of a message according to the above-mentioned standard CiA610-1 is shown, which can be replaced by a transmitting / receiving device of a user station of a bus system according to the first exemplary embodiment. Figure 2CAN FD frames are sent;

[0048] Figure 4 shows a simplified schematic block diagram of a user station of a bus system according to a first embodiment;

[0049] Figure 5 1 shows the time course of the bus signals CAN_H and CAN_L in the subscriber station according to the first embodiment;

[0050] Figure 6 1 shows the time course of the differential voltage VDIFF of the bus signals CAN_H and CAN_L in the subscriber station according to the first embodiment;

[0051] Figure 7 Shows Figure 4 A more detailed block diagram of a user station for illustrating the structure of a wake-up module of the user station;

[0052] Figure 8 A flow chart showing a method that can be performed in a bus system according to a second embodiment; and

[0053] Fig. 9 A flow chart of a method which can be performed in a bus system according to a third exemplary embodiment is shown.

[0054] In the figures, identical or functionally identical elements are provided with the same reference symbols unless otherwise indicated. DETAILED DESCRIPTION

[0055] Figure 1 As an example, a bus system 1 is shown, which is designed in particular essentially for a CAN bus system, a CAN FD bus system, a CAN XL bus system and / or their variants, as described below. The bus system 1 can be used in vehicles, in particular motor vehicles, aircraft, etc., or in hospitals, etc.

[0056] exist Figure 1 In the embodiment, the bus system 1 has a plurality of user stations 10, 20, 30, 50, which are respectively connected to a bus 40 having a first bus core 41 and a second bus core 42. The bus cores 41, 42 may also be referred to as CAN_H and CAN_L, and are used for transmitting electrical signals after coupling in a dominant level or generating a recessive level or other levels for the signal in the sending state. Via the bus 40, messages 45, 46 can be transmitted serially between the individual user stations 10, 20, 30, 50 in the form of signals. If an error occurs during communication on the bus 40, such as by Figure 1As shown by the jagged black square arrow in FIG. 1 , an error frame 47 (ErrorFrame) may be optionally sent, which has an error flag (ErrorFlag) and an error delimiter (ErrorDelimiter). Figure 1 The user stations 10 , 20 , 30 are, for example, control units, sensors, display devices, etc. of a motor vehicle or other technical systems.

[0057] The user station 50 may also be referred to as a management user station or management node or a selective awakening user station. The user station 50 is also designed to send a wake-up frame 48 for selectively awakening one of the user stations 10, 20, 30 via the bus 40 as needed. The wake-up frame 48 may also be referred to as a Wake-Up-Frame or simply WUF. Optionally, the user station 50 is also designed to send a sleep frame 49 for selectively putting one of the user stations 10, 20, 30 into a sleep state via the bus 40 as needed.

[0058] like Figure 1 As shown in FIG. 1 , the user station 10 has a communication control device 11, a transmitting / receiving device 12, and a wake-up module 15. The user station 20 has a communication control device 21, a transmitting / receiving device 22, and a wake-up module 25. The user station 30 has a communication control device 31, a transmitting / receiving device 32, and a wake-up module 35. The user station 50 has a communication control device 51, a transmitting / receiving device 52, and a management module 55. The transmitting / receiving devices 12, 22, 32, 52 of the user stations 10, 20, 30, 50 are directly connected to the bus 40, even if this is Figure 1 Not clarified.

[0059] The communication control devices 11, 21, 31, 51 are used to control the communication of the corresponding user station 10, 20, 30, 50 via the bus 40 with at least one other user station of the user stations 10, 20, 30, 50 connected to the bus 40. For this purpose, the communication control devices 11, 31 create and / or read first messages 45, which are, for example, CAN FD messages 45. These CAN FD messages 45 are constructed based on the CAN FD format, which refers to the CAN FD format. Figure 2 Described in more detail.

[0060] The communication control device 11, 31, 51 can also be designed to provide a CAN FD message 45 or a CANXL message 46 to the associated transceiver device 12, 32, 52 or receive a CAN FD message 45 or a CANXL message 46 from the transceiver device as required. These CANXL messages 46 are constructed based on the CANXL format, which refers to Figure 3The communication control device 11 , 31 , 51 thus creates and reads a first message 45 or a second message 46 , wherein the first and second messages 45 , 46 differ in their data transmission standard, namely in this case CAN FD or CAN XL.

[0061] The communication control device 21 can be implemented like a conventional CAN controller according to ISO 11898-1:2015, that is, like a CANFD-tolerant Classical CAN controller or a CAN FD controller. The communication control device 21 creates and reads a first message 45, for example a CAN FD message 45. A CAN FD message 45 can include a number of 0 to 64 data bytes, which are also transmitted at a significantly faster data rate than in the case of a Classical CAN message. In particular, the communication control device 21 is implemented like a conventional CAN FD controller.

[0062] Transmitting / receiving devices 12, 32, 52 may be designed to provide or receive messages 45 in CAN FD format or messages 46 in CAN XL format, as required, to associated communications control devices 11, 31, 52. In addition, wakeup modules 15, 35 are present, which are described in more detail below.

[0063] The transmitting / receiving device 22 can be implemented like a conventional CAN transceiver or a CAN FD transceiver according to ISO 11898-1:2015. In addition, there is a wakeup module 25 which can be implemented according to the international standard ISO 11898-2:2016, as will be explained in more detail below.

[0064] The wake-up module 15 , 35 may also be designed to receive and read a wake-up frame implemented in accordance with the international standard ISO 11898-2:2016.

[0065] The formation and subsequent transmission of messages 46 in the CAN XL format as well as the reception of such messages 46 can be achieved using these subscriber stations 10 , 30 , 50 .

[0066] Figure 2 4 shows a frame 450 for a message 45 with up to 64 data bytes in the CAN FD format, which is created by one of the user stations 10, 20, 30, 50. The CAN FD frame 450 is composed of one of the communication control devices 11, 21, 31, 51, namely the digital transmission signal TxD ( Figure 4) is provided in an encoded manner to the associated transmitting / receiving device 12, 22, 32, 52 for transmission onto the bus 40.

[0067] Frame 450 is divided into two communication phases, which are called arbitration phase 451 and data phase 452. Frame 450 starts and ends at arbitration phase 451. Frame 450 starts with SOF bit and has arbitration field 453 (Arbitration field), control field 454 (Control field), data field 455 (Data field), checksum field 456 (CRC field), acknowledgment field 457 (ACK=Acknowledge) and frame end field EOF (EOF=End of Frame). Bits in arbitration phase 451 of frame 450 have longer bit time than bits in data phase 452, such as Figure 2 As illustrated by way of example in .

[0068] exist Figure 2 The bits shown with thick lines at the line below them in 450 are sent as dominant or "0" in frame 450. Figure 2 The bits shown in bold at the line above them are sent as recessive or "1" in frame 450. Figure 2 Such bits, shown in bold in FIG. 4 , have predetermined fixed or specified values ​​in frame 450 .

[0069] In the base-ID field and the ID-ext field, the arbitration field 453 includes an identifier of the frame 450. The identifier has 29 bits. An SRR bit and an IDE bit are provided between the base-ID field and the ID-ext field. An RRS bit is arranged at the end of the arbitration field 453.

[0070] The control field 454 begins with the FDF bit, followed by the res bit. Then the BRS bit and the ESI bit. The control field 454 ends with the DLC field, in which the length of the subsequent data field 455 is encoded. For frame 450, the res bit must be sent with a logic value of 0, in other words as a (logic) 0, i.e., explicitly. However, if the user station 20 receives a res bit with a logic value of 1, in other words as a (logic) 1, i.e., recessive, the receiving user station 20 sees a protocol abnormal event PAE and enters a re-integrated state or operating mode.

[0071] If the DLC field of the control field 453 has a value of 0, then there is no data field 455. The data field 455 has a length corresponding to the value encoded in the DLC field. This value can be up to 64 bytes, as described above.

[0072] In the SBC field, the checksum field 456 contains a number of stuffing bits modulo 8, which are inserted into the frame 450 according to the bit stuffing rule, that is, one opposite bit is inserted after each of five identical bits. In addition, in the CRC field, the checksum field 456 contains a CRC checksum, which can also be called a CRC checksum, and ends with a CRC delimiter CRC-Del following it.

[0073] The acknowledgement field 457 contains an ACK-Slot bit, at which a user station, which is currently only a receiver of the frame 450 but not a transmitter of the frame, can acknowledge or not acknowledge the correct receipt of the frame 450 from the bus 40. The acknowledgement field 457 ends with an ACK-Del bit, which is also called an ACK-Delimiter.

[0074] A bit sequence is provided in the end-of-frame field EOF, which bit sequence marks the end of the frame 450. The bit sequence of the end field (EOF) is thereby used to indicate the end of the frame 450. The end field (EOF) together with the ACK delimiter causes 8 recessive bits to be sent at the end of the frame 450. This is a bit string that cannot occur within the frame 450. As a result, the subscriber station 10, 20, 30 can reliably recognize the end of the frame 450.

[0075] In frame 450, the end field (EOF) is followed by Figure 2 The interframe space (IFS—InterFrame Space) not shown in FIG. In the case of CAN FD, the interframe space (IFS) is designed according to ISO 11898-1:2015. The interframe space (IFS—InterFrame Space) has at least 3 bits.

[0076] Furthermore, the mentioned fields and bits are known from ISO 11898-1:2015 and are therefore not described in more detail here.

[0077] In the case of CAN FD, in an arbitration phase 451, by means of an identifier (ID) in an arbitration field 453 with, for example, bits ID28 to ID18, it is negotiated bit by bit between the user stations 10, 20, 30: which user station 10, 20, 30 wants to send the highest priority message 45, 46 and thus obtain exclusive access to the bus 40 of the bus system 1 for the next transmission in the subsequent data phase 452. In the arbitration phase 451, a physical layer is used, as in the case of CAN and CAN-FD. The physical layer corresponds to the bit transmission layer or layer 1 of the well-known OSI model (Open Systems Interconnection Model 1).

[0078] The key point during this phase 451 is that the known CSMA / CR method is used, which allows simultaneous access of the bus 40 by the user stations 10, 20, 30 without destroying the higher priority messages 45, 46. This makes it relatively easy to add further bus user stations 10, 20, 30 to the bus system 1, which is very advantageous.

[0079] The CSMA / CR method requires that so-called recessive states must be present on the bus 40, which can be overwritten by other subscriber stations 10, 20, 30 with dominant states on the bus 40. In the recessive state, high impedance conditions exist at the individual subscriber stations 10, 20, 30, which, combined with the parasitics of the bus wiring, lead to longer time constants. This results in the current maximum bit rate of the CAN-FD physical layer being limited to approximately 2 megabits per second in real vehicle use. With the new CAN SIC physical layer, 5 megabits per second and up to 8 megabits per second can also be achieved.

[0080] In the data phase 452, in addition to part of the control field 454 of the frame 450, the useful data of the CAN FD frame 450 or message 45 from the corresponding data field 455 and the associated checksum field 456 are also transmitted. Then, the data phase 452 switches back to the arbitration phase 451.

[0081] Only when the subscriber station 10 as sender has won the arbitration and thereby has exclusive access to the bus 40 of the bus system 1 for sending, does the subscriber station 10 as sender of the message 45, 46 start to send the bits of the data phase 452 onto the bus 40. The same applies to the subscriber stations 20, 30 when they want to send a message 45 or 46 onto the bus 40.

[0082] Figure 3For message 46, a CAN XL frame 460 is shown, which is provided by communication control device 11, namely encoded in the digital transmission signal TxD, to the transmitting / receiving device 12 for transmission to bus 40. In this case, communication control device 11 constructs frame 460 in the present exemplary embodiment to be compatible with CAN FD, as in Figure 3 The same applies analogously to the communication control devices 31 , 51 of the subscriber stations 30 , 50 and the associated transmitting / receiving devices 32 , 52 .

[0083] according to Figure 3 , the CAN XL frame 460 is also divided into different communication phases 451, 452 for CAN communication on the bus 40, namely, the arbitration phase 451 and the data phase 452. After the start bit (SOF), the frame 460 has: an arbitration field 463; a control field 464, which has an ADS field for switching between the communication phases 451, 452; a data field 465; a checksum field 466; and a frame end field 467. Then there is the frame end field EOF, as in accordance with Figure 2 As in frame 450 of .

[0084] In the arbitration phase 451, arbitration is also performed for the frame 460 by means of an identifier (ID), as previously described with reference to Figure 2 In the data phase 452, in addition to a portion of the control field 464 of the frame 460, the valid data from the data field 465 and the checksum field 466 of the CAN-XL frame 460 or message 46 are transmitted. Figure 3 The CAN XL is then followed by the DAS field, which is used to switch back from the data phase 452 to the arbitration phase 451.

[0085] like Figure 3 As shown in FIG. , the user station 10 partially uses the format according to ISO 11898-1:2015 known from CAN / CAN-FD, in the arbitration phase 451 as the first communication phase, in particular up to and including the FDF bit, such as Figure 2 As shown in and described previously. On the other hand, the user station 10 uses the CAN XL format starting from the FDF bit in the first communication phase and in the data phase 452 as the second communication phase, which format is described later. For transmission on the bus 40, in the CAN XL data phase 452, symmetrical "1" and "0" levels are used instead of recessive and dominant levels as in CAN FD.

[0086] Generally, two different filling rules are applied when generating the frame 460. Until the FDF bit in the arbitration field 453, CAN FD or Figure 2 The dynamic bit stuffing rule of the frame 450 is such that after 5 consecutive identical bits, an opposite stuffing bit should be inserted. In the data stage 452 and before the FCP field, a fixed stuffing rule applies, such that after a fixed number of bits, a fixed stuffing bit should be inserted, which is the opposite of the previous bit. Alternatively, instead of only one stuffing bit, 2 or more bits can be inserted as fixed stuffing bits.

[0087] In the present exemplary embodiment, the res bit known from CAN FD is used for switching from the CAN FD format to the CAN XL format and is represented by the XLF bit in frame 460. Thus, up to the res bit or the XLF bit, the frame formats of CAN FD and CAN XL are identical. The receiver recognizes at this bit the format in which the frame 460 is sent. CAN XL user stations, i.e. here user stations 10, 30, also support CAN FD. If this bit is sent as 1, i.e. implicitly, it is the XLF bit and thereby identifies the frame 460 as a CAN XL frame. For Figure 2 For a CAN FD frame, the communication control device 11 sets this bit to 0, that is, sets it to the dominant res bit.

[0088] In frame 460, the XLF bit is followed by the resXL bit, which is a dominant bit for future use. For frame 460, resXL must be sent as 0, i.e. explicitly. However, if the resXL bit received by the user station 10 is 1, i.e. recessive, the receiving user station 10 sees, for example, a protocol exception event PAE (also called Protocol Exception Event) and takes action as implemented for res=1 in the case of CAN FD message 46. If the synchronization from the recessive XLF bit to the dominant ResXL bit does not require the resXL bit, the resXL bit may be defined in the exact opposite way, i.e., the resXL bit must be sent as 1, i.e. recessively. In this case, the receiving user station sees the protocol exception event PAE at the dominant resXL bit and changes its operating mode to reintegration.

[0089] In frame 460, after the resXL bit is an ADS (Arbitration Data Switch) sequence, in which a predetermined bit sequence is encoded. This bit sequence allows a simple and reliable switch from the bit rate of the arbitration phase 451 (arbitration bit rate) to the bit rate of the data phase 452 (data bit rate). Optionally, within the ADH bit, the operating mode of the transmitting / receiving device 12, 32 is switched from the operating mode B_451 (SLOW) of the arbitration phase 451 to one of the two operating modes B_452_TX, B_452_RX of the data phase 452. The two operating modes of the data phase 452 are: the operating mode B_452_TX (FAST_TX) for the transmitting node, which allows its signal to be sent to the bus 40 during the data phase 452; and the operating mode B_452_RX (FAST_RX) for the receiving node, which is only the receiver of the signal from the bus 40.

[0090] The following fields are not described in more detail here until the start of the data field 465. The data field 465 may have up to 2048 bytes.

[0091] In frame 460, following the data field 465 is a checksum field 466, which has a frame checksum FCRC and an FCP field. In this case, FCP=Frame Check Pattern applies. The FCP field consists of 4 bits, in particular with the bit sequence 1100. The receiving node uses the FCP field to check whether it is bit-synchronized with the transmit data stream. In addition, the receiving node is synchronized with the falling edge in the FCP field.

[0092] Following the FCP field is the frame termination field 467. The frame termination field 467 consists of two fields, namely a DAS field, and an acknowledgement field or ACK field having at least one bit ACK and an ACK-D1m bit.

[0093] The DAS field contains the sequence DAS (Data Arbitration Switch), in which a predetermined bit sequence is encoded. The bit sequence DAH, AH1, AL1 allows a simple and reliable switch from the data bit rate of the data phase 452 to the arbitration bit rate of the arbitration phase 451. In addition, during the DAS field, the operating mode of the transmitting / receiving device 12, 32 is switched, optionally from the operating mode B_452_TX or B_452_RX (FAST) to the operating mode B_451 (SLOW). Within the DAH bit, the operating mode of the physical layer (Physical Layer), that is, the transmitting / receiving device 12, 32, is switched from FAST_TX or FAST_RX to SLOW. Bit AH1 is followed by bit AL1 (logic 0) and bit AH2 (logic 1). The two bits DAH and AH1 ensure that there is sufficient time for the operating mode change of the transmitting / receiving device 11 and that all subscriber stations 10, 30 see a recessive level for significantly more than one arbitration bit time before the edge at the beginning of the AL2 bit (logic 0). This ensures safe synchronization of the subscriber stations of the bus system.

[0094] The sequence of DAS fields is followed by an acknowledgement field (ACK) in the frame termination field 467. In the acknowledgement field, a bit for acknowledging or not acknowledging that the frame 460 is correctly received is provided.

[0095] In frame 460, after the frame termination field 467 is the frame end field (EOF = End of Frame), as in the Figure 2 as in CAN FD.

[0096] For a user station for which error signaling is not activated and which sends a CAN XL frame, the End of Frame field (EOF) has a different length depending on whether a dominant or recessive bit is seen in the ACK bit. If the ACK bit received by the sending user station is dominant, the End of Frame field (EOF) has 7 recessive bits. Otherwise, the length of the End of Frame field (EOF) is only 5 recessive bits.

[0097] In frame 450, after the end of frame field (EOF) is the inter-frame space (IFS), as previously described with respect to Figure 2 As illustrated in frame 450 .

[0098] The following applies here for CAN XL.

[0099] - Unlike CAN FD, in the case of CAN XL the identifier ID of the frame 460 is called “Priority ID”.

[0100] - Unlike CAN FD, CANXL can send the RRS bit as a (logical) 0 or as a (logical) 1. In CAN FD, the RRS bit is always sent as a logical 0.

[0101] In the case of CAN XL, the bit rate in the data phase 452 must be at least 2 times higher than the bit rate in the arbitration phase 451 .

[0102] Figure 4 The basic structure of the user station 10 is shown, and the user station has a communication control device 11, a transmission / reception device 12 and a wake-up module 15, which is a part of the transmission / reception device 12. Figure 4 The case shown in the figure is constructed in a similar manner, however, according to Figure 1 The wake-up module 35 is arranged independently of the communication control device 31 and the transmission / reception device 32. Therefore, the user station 30 is not described separately.

[0103] according to Figure 4 In addition to the communication control device 11, the transmission / reception device 12 and the wake-up module 15, the user station 10 has: a microcontroller 13, to which the communication control device 11 is assigned; and a system ASIC 16 (ASIC=application-specific integrated circuit), which can alternatively be a system basis chip (SBC) on which a plurality of functions required for the electronic components of the user station 10 are combined. In addition to the transmission / reception device 12, an energy supply device 17 is installed in the system ASIC 16, which supplies the transmission / reception device 12 with electrical energy. The energy supply device 17 usually provides a voltage CAN_Supply of 5V. However, according to requirements, the energy supply device 17 can provide different voltages with different values. In addition or alternatively, the energy supply device 17 can be designed as a current source.

[0104] The transmitting / receiving device 12 also has a transmitting module 121 and a receiving module 122. Even if the transmitting / receiving device 12 is always mentioned below, the receiving module 122 can alternatively be arranged in a separate device outside the transmitting module 121. The transmitting module 121 and the receiving module 122 can be designed as in the case of a conventional transmitting / receiving device 22. The transmitting module 121 can have at least one operational amplifier and / or a transistor. The receiving module 122 can have at least one operational amplifier and / or a transistor.

[0105] The transmitting / receiving device 12 is connected to a bus 40, more precisely to a first bus line 41 for CAN_H and a second bus line 42 for CAN_L of the bus. The voltage supply of the energy supply device 17 is realized via at least one connection 43, in order to supply electrical energy, in particular the supply voltage CAN-Supply, to the first and second bus lines 41, 42. The connection to ground or CAN_GND is realized via a connection 44. The first and second bus lines 41, 42 are terminated by a terminating resistor 409.

[0106] In the transmitting / receiving device 12, the first and second bus cores 41, 42 are connected both to a transmitting module 121, also called a transmitter, and to a receiving module 122, also called a receiver. Figure 4 For the sake of simplicity, this connection is not shown.

[0107] When the bus system 1 is in operation, the transmission module 121 can convert the transmission signal TxD of the communication control device 11 transmitted via the terminal TXD into corresponding signals CAN_H, CAN_L for CAN or CAN FD and CAN_XL_H, CAN_XL_L in CANXL for the bus cores 41, 42, and transmit these signals to the bus 40 at the terminals for CAN_H and CAN_L. As described above, the digital transmission signal TxD is based on Figure 2 CAN FD frame 450 or Figure 3 CAN XL frame 460.

[0108] The receiving module 122 receives Figure 5 The digital reception signal RxD is formed by using the signals CAN_H and CAN_L received from the bus 40 shown in FIG. 1 , and the digital reception signal is transferred to the communication control device 11, as shown in FIG. Figure 4 as shown in .

[0109] according to Figure 5 In the example of FIG. 4 , the signals CAN_H and CAN_L have dominant and recessive bus levels 401 , 402 at least in the arbitration phase 451 , as is known from CAN. Figure 64 shows a differential signal VDIFF=CAN_H–CAN_L for the arbitration phase 451. In order to identify the individual bits of the signal VDIFF with the bit time t_bt1, the receiving module 122 uses a receiving threshold T_a of, for example, 0.7 V in the arbitration phase 451. In the data phase 452, the bits of the signals CAN_H and CAN_L can be sent faster than in the arbitration phase 451, i.e. with a shorter bit time t_bt2. Therefore, for CAN FD and CAN XL, the signals CAN_H and CAN_L in the data phase 452 differ from the conventional signals CAN_H and CAN_L at least in their faster bit rate. If necessary, the receiving module 122 uses at least one receiving threshold in the data phase 452 that is different from that in the arbitration phase 451.

[0110] Figure 5 The sequence of states 401, 402 of the signals CAN_H and CAN_L in Figure 6 The course of voltage VDIFF serves only to clarify the function of subscriber station 10. The sequence of data states for bus states 401, 402 can be selected as required.

[0111] In other words, according to Figure 5 , the sending module 121 generates: a first data state, as a bus state 402 with different bus levels for the two bus cores 41 and 42 of the bus line; and a second data state, as a bus state 401 with the same bus level for the two bus cores 41 and 42 of the bus line of the bus 40 when the sending module is switched to the first operating mode B_451 (SLOW).

[0112] Furthermore, for the time course of the signals CAN_H, CAN_L in the second operating mode B_452_TX (FAST_TX) including the data phase 452 in the case of CAN FD and CAN XL, the transmission module 121 transmits bits to the bus 40 at a higher bit rate. In the data phase 452 of CAN XL, the CAN_H and CAN_L signals can also be generated using a different physical layer than in the case of CAN FD. As a result, the bit rate in the data phase 452 can be further increased compared to the case of CAN FD. At least for CAN XL, if a user station (receiving node) is not the sender of the frame 450 in the data phase 452, that is, not a sending node, then the user station sets the third operating mode B_452_RX (FAST_RX) in its transmission / reception device.

[0113] In operating mode B_LB (Idle), the communication control device 11 is switched to an idle or standby state. That is, the communication control device waits for the reception of messages 45, 46. In this state, no communication takes place on the bus 40. In other words, in Figure 4 No signal is received at the RXD terminal of the communication control device 11 or the value logic 1 is attached, because the recessive level on the bus 40 corresponds to the bit value = 1 or logic 1 in the received signal RxD.

[0114] In the following, also based on Figure 7 The operating principle of the wake-up module 15 is described below, which is different from the current communication standards of Classical CAN, CAN FD and CAN XL.

[0115] Figure 7 The basic structure of the wake-up module 15 of the transmitting / receiving device 12 of the user station 10 is shown. Figure 7 Only the signals and blocks relevant to the wake-up module 15 are shown in FIG. 1 , as follows: The wake-up module 15 has a received signal decoding block 151 , a clock block 152 , an evaluation block 153 and a configuration block 154 .

[0116] The clock block 152 outputs a clock T1 at a frequency f to the received signal decoding block 151. The evaluation block 153 can output a signal SW1 to the energy supply device 17.

[0117] When the bus system 1 is in operation, the user station 10 can be put into sleep mode by means of the frame 49, as described above. In other words, the user station 10 is put into sleep mode by means of the frame 49. Whether a frame 49 for entering sleep mode has been received can be evaluated by software, which is implemented in particular in the evaluation block 153 or in a block not shown.

[0118] In the sleep mode, the transmission module 121 is disabled in the transmission / reception device 12. In the sleep mode, the transmission / reception device 12 does not drive the signals CAN_H and CAN_L onto the bus 40.

[0119] In order to recognize when the sleep mode should be exited again, the wake-up module 15 takes the following actions.

[0120] The receiving module 122 decodes the digital receiving signal RxD according to the signals CAN_H and CAN_L by means of the receiving threshold value, as has been described previously. The receiving module 122 outputs the digital receiving signal RxD to the receiving signal decoding block 152 .

[0121] The received signal decoding block 151 decodes the digital bit stream in the received signal RxD and outputs the result to the evaluation block 153. For decoding of the bit stream, the received signal decoding block 151 uses the clock T1 received from the clock block 152.

[0122] The evaluation block 153 is designed to filter and compare the results received from the block 151. In this case, the evaluation block 153 evaluates whether the CAN frames 45, 46, 47, 48, 49 received from the bus 40 correspond to the previously specified format of the wake-up frame 48. To this end, the evaluation block 153 uses at least one of the wake-up conditions 1541, 1542, 1543 stored in the configuration block 154. For example, the wake-up conditions 1541, 1542, 1543 may include at least one of the following conditions / parameters: namely, the identifier ID (priority ID) of the wake-up frame 48, the value of the RRS bit, the combination of the identifier ID (priority ID) of the wake-up frame 48 and the value of the RRS bit. Of course, other or additional conditions / parameters 1541, 1542, 1543 can be used.

[0123] For the evaluation of block 153, block 151 decodes the CAN XL frame 460 in the incoming receive signal RxD until the resXL bit ( Figure 3 Alternatively, block 151 decodes the CAN XL frame 460 in the incoming receive signal RxD only up to the RRS bit.

[0124] Until resXL position ( Figure 3 ), the evaluation block 153 identifies whether it is a wake-up frame 48.

[0125] If the evaluation block 153 evaluates that the CAN frame 45, 46, 47, 48, 49 received from the bus 40 corresponds to the previously specified format of the wake-up frame 48, the evaluation block 153 outputs a corresponding signal SW1 to the energy supply device 17. The signal SW1 can be, for example, a switching signal which is designed to switch on the energy supply device 17.

[0126] The evaluation block 153 can also be designed to evaluate whether the CAN frames 45, 46, 47, 48, 49 received from the bus 40 correspond to the previously specified format of the sleep frame 49 by filtering and comparing the results received from the block 151. To this end, the evaluation block 153 uses at least one parameter of the parameters 1541, 1542, 1543 stored in the configuration block 154. For example, the parameters 1541, 1542, 1543 can include at least one of the following parameters: the identifier ID (priority ID) of the sleep frame 49, the value of the RRS bit, the combination of the identifier ID (priority ID) of the sleep frame 49 and the value of the RRS bit. Of course, other or additional parameters 1541, 1542, 1543 can be used.

[0127] If the evaluation block 153 evaluates that the CAN frame 45, 46, 47, 48, 49 received from the bus 40 corresponds to the previously specified format of the sleep frame 49, the evaluation block 153 outputs a corresponding signal SW1 to the energy supply device 17. The signal SW1 can be, for example, a switching signal which is designed to switch off the energy supply device 17.

[0128] If the transceiver device 12 is in sleep mode, the transceiver device 12 , in particular its wakeup module 15 , detects whether the transceiver device should be woken up, for example, as follows.

[0129] Therefore, the evaluation block 153 evaluates the incoming CAN XL frame 460 or the corresponding receive signal RxD only until the resXL bit ( Figure 3 ) until the resXL bit is previously referenced Figure 3 Alternatively, the evaluation block 153 only performs the evaluation until the RRS position ( Figure 3 )until.

[0130] Until the resXL bit, ie before the data field 465, the evaluation block 153 identifies whether it is a wake-up frame 48. This identification is made according to one of the following conditions, namely

[0131] a). The value of the RRS bit is logic 0 or logic 1;

[0132] b). The value of the priority ID.

[0133] According to a first modification of the evaluation block 153 , the evaluation block 153 is designed to evaluate a combination of the above conditions a) and b) in order to identify whether it is a wake-up frame 48 .

[0134] According to the second modification of the evaluation block 153, the evaluation block 153 outputs the signal SW1 for switching on the energy supply device 17 only when the evaluation block 153 has received the wake-up frame 48 N times within a predetermined time period or after the predetermined time period has expired. N is a natural number greater than 1, in particular 2, or any other natural number greater than 1. The predetermined time period is in particular 3 ms or any other time period. N and the predetermined time period are parameters stored in the parameters 1541, 1542, 1543 in the configuration block 154.

[0135] If CAN FD communication is performed on the bus 40 instead of CAN XL communication, the wake-up module 25 of the user station 20 can also be put into a dormant state or woke up, as described in ISO standard 11898-2: 2016. For this purpose, the wake-up module 25 is constructed in part the same as the wake-up module 15. However, the configuration of the configuration block 154 is designed differently from the case described previously with respect to the wake-up module 15. In addition, however, the wake-up module 25 can have a design and configuration as described below.

[0136] At the user station 20 , the wake-up module 25 checks whether the user station 20 should enter a sleep state or should be woken up as specified in the ISO 11898-2:2016 standard as follows.

[0137] Therefore, the wake-up module 25 may be configured to check the following conditions for wake-up:

[0138] Whether the CAN identifier (which may also be referred to as frame identifier) ​​of the received frame 45 , 46 , 48 , 49 corresponds to the CAN identifier provided for the wake-up frame 48 .

[0139] - whether the data length of the received frame 45 , 46 , 48 , 49 in the DLC coding corresponds to the data length specified for the wake-up frame 48 .

[0140] - Whether the data mask of the received frame 45, 46, 48, 49 corresponds to the data mask in the data field 455 of the wake-up frame 48 or to a "1" bit in which the subscriber station 20 should be woken up.

[0141] If the wake-up module 25 determines that all of the conditions mentioned are met for the received frames 45, 46, 48, 49, i.e. frame 48 is received, the wake-up module 25 performs a wake-up. Therefore, the transmission module 121 is activated again. This method is described in more detail in the ISO 11898-2:2016 standard.

[0142] Figure 8A second exemplary embodiment of a bus system 1 is described, in which the transmitting / receiving devices 10, 30, 50, in particular their wake-up modules 15, 35, 55, are designed for selective wake-up simulated in software. It is then also assumed that the subscriber station 20 is also designed for sending and receiving CAN XL frames. Alternatively, at least one additional further subscriber station 10 and / or at least one additional CAN FD subscriber station 20 may also be present. The subscriber station 50 is a management subscriber station which uses only one condition, in particular the RRS bit, to recognize the wake-up frame 48.

[0143] In this case, the following process can be generated.

[0144] 1. All user stations 10, 20, 30, 50 on the bus 40 are awake and communicating.

[0145] 2. The user station 50 puts the user stations 20 , 30 into sleep mode using a CAN XL frame, ie, a sleep frame 49 .

[0146] 3. The user stations 10, 50 can continue to communicate without waking up the user stations 20, 30.

[0147] 4. After a certain period of time, the function of the user station 30 is needed again, so that the user station 30 should be woken up.

[0148] Therefore, the user station 50, in particular its wake-up module 55, executes the following Figure 8 The method shown in .

[0149] according to Figure 8 After its start, the method first proceeds to step S1. In step S1, the user station 50 creates a wake-up frame 48 for the user stations 20, 30 and sends it via the bus 40. In this example, the wake-up frame 48 is a CANXL frame, in which the bit RRS=1. The method then continues to step S2.

[0150] In step S2, the user station 20, 30 receives the wake-up frame 48, as previously described with reference to Figure 7 As described. As a result, both subscriber stations 20, 30 are awakened, since their evaluation modules 25, 30 recognize the wake-up frame 48 at the value of the RRS bit, since RRS=1 applies. The method then continues to step S3.

[0151] In step S3, the user station 50 puts the user station 20 to sleep again. To this end, the user station 50 creates a sleep frame 49, as described above, and sends it via the bus 40. The method then continues to step S4.

[0152] In step S4, the user station 20 receives the sleep frame 49, as previously described with reference to Figure 7 As described. As a result, the energy supply device 17 of the user station 20 is deactivated and the user station 20 is in sleep mode. The user stations 10, 30, 50 are awake and can communicate. The method then ends.

[0153] Alternatively, the method can return to step S1. According to another alternative, the method continues to a further step in which the user station 50 sends a wakeup frame 48 for waking up other user stations of the bus system 1 or a sleep frame 49 for putting other user stations of the bus system 1 into a sleep state.

[0154] Identifying the wakeup frame 48 solely via the RRS bit is advantageous because no separate frame 48 has to be sent. Instead, the wakeup signaling is integrated into the next frame 460 that is sent anyway by simply sending the RRS bit appropriately, for example as RRS=1. This increases the net data rate that can be transmitted on the bus 40.

[0155] Fig. 9 A third exemplary embodiment of a bus system 1 is described, in which the transmitting / receiving devices 10, 30, 50, in particular their wake-up modules 15, 35, 55, are designed for (real) selective wake-up. It is also assumed again that the subscriber station 20 is also designed for sending and receiving CAN XL frames. Alternatively, at least one additional further subscriber station 10 may also be present. The subscriber station 50 is a management subscriber station, which uses two conditions, in particular the RRS bit and the priority ID, to recognize the wake-up frame 48.

[0156] In this case, processes 1 to 4 can be reproduced, which were previously described with respect to the second embodiment.

[0157] Therefore, in the current embodiment, for selective awakening, the user station 50, especially its awakening module 55, executes the following steps: Fig. 9 The method shown in .

[0158] according to Fig. 9 , the method first proceeds to step S11 after its start. In step S11, the user station 50 creates a wake-up frame 48 for the user station 30 and sends the wake-up frame via the bus 40. In this example, the wake-up frame 48 is a CANXL frame, in which the bit RRS=1 and the priority ID has the value expected by the wake-up module 35 for the wake-up frame 48 according to the configuration in the configuration block 154. Then, the method continues to step S12.

[0159] In step S12, the user station 30 receives the wake-up frame 48, as previously described with reference to Figure 7As described. As a result, the subscriber station 30 is awakened, since its evaluation module 25, 30 recognizes the wake-up frame 48 at the value of the RRS bit and at the value of the priority ID. The method then continues to step S13.

[0160] In step S13, the user station 10, 30, 50 is awake and can communicate. The method then ends.

[0161] Alternatively, the method can return to step S11. According to another alternative, the method continues to a further step in which the user station 50 sends a wakeup frame 48 for waking up other user stations of the bus system 1 or a sleep frame 49 for putting other user stations of the bus system 1 into a sleep state.

[0162] The identification of the wake-up frame 48 on the basis of the priority ID (=11-bit frame ID=11-bit frame identifier) ​​has the advantage that selective awakening of the individual subscriber stations 10, 20, 30 is possible. The selective awakening possible thereby avoids unnecessary awakening and reentry into the sleep state and the resulting data traffic on the bus 40. As a result, not only can the energy consumption of the bus system 1 be reduced to a minimum, but also the net data rate that can be transmitted on the bus 40 can be increased.

[0163] All of the above-described embodiments of the user stations 10, 20, 30 of the bus system 1 and the methods executed therein can be used individually or in all possible combinations. In particular, all features of the above-described embodiments and / or their modifications can be combined as desired. Additionally or alternatively, the following modifications are particularly conceivable.

[0164] Even though the present invention has been described above using a CAN bus system as an example, the present invention can also be used in any communication network and / or communication method in which two different communication phases are used, in which the bus states generated for these different communication phases are different.

[0165] The bus system 1 according to these exemplary embodiments can in particular be a communication network in which data can be transmitted serially at two different bit rates. An advantageous, but not mandatory, prerequisite is that exclusive, conflict-free access to a common channel is ensured for the user stations 10, 20, 30 in the bus system 1 at least within a certain time interval.

[0166] The number and arrangement of the user stations 10, 20, 30, 50 in the bus system 1 of these embodiments are arbitrary. In particular, the user station 20 in the bus system 1 can be omitted. It is possible that one or more of the user stations 10 or 30 are present in the bus system 1. It is conceivable that all the user stations in the bus system 1 are designed identically, that is, only the user station 10 or only the user station 30 is present.

Claims

1. A transmitting / receiving device (12; 32; 52) for selectively waking up a user station (10; 30) of a serial bus system (1), the transmitting / receiving device comprising: a transmission module (121) for transmitting a transmission signal (TxD) as an analog signal (VDIFF) to a bus (40) of the bus system (1), the transmission signal being created for communication based on frames (450; 460) in the bus system (1); a receiving module (122) for receiving the analog signal (VDIFF) from a bus (40) of the bus system (1), and for generating a digital receiving signal (RxD) according to the analog signal (VDIFF) received from the bus (40); and A wake-up module (15; 35; 55) is used to wake up the user station (10; 30) after the user station (10; 30) enters a dormant state for energy saving, in, The wake-up module (15; 35; 55) is designed to evaluate at least one wake-up condition (1541; 1542; 1543) in order to determine whether the digital reception signal (RxD) corresponds to a wake-up frame (48) indicating activation of the transmission module (121) in order to wake up the user station (10; 30), and The wake-up module (15; 35; 55) is designed to make a judgment as to whether the digital receive signal (RxD) corresponds to the wake-up frame (48) before the receive module (122) serially forwards the data field (465) of valid data for the frame (460) encoded in the digital receive signal (RxD) to the wake-up module (15; 35; 55).

2. The transmitting / receiving device (12; 32; 52) according to claim 1, wherein: The at least one wake-up condition (1541; 1542; 1543) is a priority ID, which determines at what time priority the frame (460) is allowed to be sent to the bus (40).

3. The transmitting / receiving device (12; 32; 52) according to claim 1 or 2, wherein: The at least one wake-up condition (1541; 1542; 1543) is a single bit that is arranged in the received frame (460) immediately after the priority ID.

4. The transmitting / receiving device (12; 32; 52) according to claim 3, wherein: The received frame is a CAN XL frame (460) and the single bit is the RRS bit.

5. The transmitting / receiving device (12; 32; 52) according to any one of the preceding claims, in, The wake-up module (15; 25; 35) is designed to perform wake-up only when the wake-up module (15; 35; 55) has evaluated that a wake-up frame (48) has been received N times within a predetermined time length (1542) using a digital reception signal (RxD) received serially, Wherein, N is a natural number greater than 1.

6. The transmitting / receiving device (12; 32; 52) according to any one of the preceding claims, wherein: The wake-up module (15; 25; 35) comprises: a decoding block (151) for decoding a reception signal (RxD) output by the reception module (122) based on the frame (460), the analog signal (VDIFF) being created on the bus (40) of the bus system (1); and An evaluation block (153) is used to evaluate the result output by the decoding block (151) to determine whether the digital reception signal (RxD) corresponds to the wake-up frame (48).

7. The transmitting / receiving device (12; 32; 52) according to any one of the preceding claims, The transmitting / receiving device also has a configuration block (154) for storing the at least one wake-up condition (1541; 1542; 1543), in, The evaluation block (153) is designed to perform an evaluation of the evaluation block when accessing the configuration block (154) and to generate a signal (SW1) for activating an energy supply to the transmission module (121) when the digital reception signal (RxD) corresponds to the wake-up frame (48).

8. A user station (10; 20; 30; 50) comprising: A transmitting / receiving device (12; 32; 52) according to any one of the preceding claims; and A communication control device (11; 21; 31) is designed to sample and evaluate a reception signal (RxD) generated by the transmission / reception device (12; 32; 52) according to a predetermined frame (450; 460).

9. The user station (10; 20; 30; 50) according to claim 8, wherein: The communication control device (11; 21; 31; 51) is designed to control the communication between the user station (10; 20; 30; 50) and at least one other user station (20; 30; 10) of the bus system (1), and to evaluate the received signal (RxD), in which the bit time (t_bt1) in a first communication phase (451) can be different from the bit time (t_bt2) in a second communication phase (452).

10. The user station (10; 20; 30) according to claim 9, wherein The communication control device (11; 21; 31) is designed to negotiate with other user stations (10; 20; 30) in the first communication phase (451): which user station (10, 20, 30) of the bus system (1) obtains at least temporarily exclusive, conflict-free access to the bus (40) in a subsequent second communication phase (452).

11. The user station (50) according to any one of claims 8 to 10, wherein: The subscriber station is designed to send a wake-up frame (48) to a bus (40) of the bus system (1) in order to selectively wake up at least one other subscriber station (10; 30) of the bus system (1) after entering a sleep state.

12. A bus system (1), comprising: bus(40); The first user station (50) according to claim 11; and At least one second user station (10; 20; 30) according to any one of claims 8 to 10, which is connected to the first user station (50) via the bus (40) so that these user stations (10; 20; 30; 50) can communicate serially with each other.

13. A method for selectively waking up a user station (10; 30) in a serial bus system (1), wherein: The method is performed using a transmitting / receiving device (12; 32; 52), the transmitting / receiving device having a transmitting module (121), a receiving module (122) and a wake-up module (15; 25; 35), wherein the method comprises the following steps: Using the transmission module (121), a transmission signal (TxD) is transmitted as an analog signal (VDIFF) to a bus (40) of the bus system (1), wherein the transmission signal is created for communication based on frames (450; 460) in the bus system (1); Using the receiving module (122), receiving the analog signal (VDIFF) from the bus (40) of the bus system (1); Using the receiving module (122), generating a digital receiving signal (RxD) according to the analog signal (VDIFF) received from the bus (40); Using the wake-up module (15; 35; 55), after the user station (10; 30) enters a sleep state for energy saving, the user station (10; 30) is woken up. wherein the wake-up module (15; 35; 55) evaluates at least one wake-up condition (1541; 1542; 1543) in order to determine whether the digital reception signal (RxD) corresponds to a wake-up frame (48) indicating activation of the transmission module (121) to wake up the user station (10; 30), and Wherein, before the receiving module (122) serially forwards the data field (465) of valid data for a frame (460) encoded in the digital receiving signal (RxD) to the wake-up module (15; 35; 55), the wake-up module (15; 35; 55) makes a judgment as to whether the digital receiving signal (RxD) corresponds to the wake-up frame (48).

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