Communication system and method

Abstract

The invention relates to a system for a communication node at an interface between Ethernet communication and CAN communication, said system and / or method being configured to ensure a small geometry and prevent data loss.

Description

Technical Field

[0001] The present disclosure relates to a system and a method. Background Art

[0002] In-vehicle network buses, such as controller area network (CAN), CAN with flexible data-rate (CAN FD), local interconnect network (LIN), FlexRay, Ethernet-based network buses, and other types, can be used for in-vehicle communications.

[0003] For example, the CAN bus is a message-based communication bus protocol commonly used in motor vehicles. However, CAN networks also have applications outside the automotive field. A CAN bus network can include multiple bus devices called nodes or electronic control units (ECUs), such as engine control modules (ECMs), powertrain control modules (PCMs), airbags, anti-lock brakes, cruise control, electric power steering, audio systems, windows, doors, mirror adjustments, batteries and charging systems for hybrid / electric vehicles, etc.

[0004] The CAN protocol is used to enable communication between various CAN bus devices. The data link layer of the CAN protocol is standardized as the International Organization for Standardization (ISO) 11898-1:2003. CAN Flexible Data-rate or "CAN FD" is an extension of the standardized CAN data link layer protocol, which has been integrated into the ISO11898-1:2015 standard and provides higher data rates. Another extension, called CAN XL, has a new (optional) layer scheme on the physical layer to achieve even higher data rates. This extension is currently in the definition stage under discussion according to CiA610 (CAN in Automation) and is moving towards standardization in the form of ISO11898-1:202x.

[0005] Ethernet is a well-known networking technology, and IEEE 802.3 (Institute of Electrical and Electronics Engineers) refers to a set of standards that define the media access control of the physical layer and data link layer of wired Ethernet. For example, modern cars contain various electronic control units that communicate with each other through an in-vehicle network (IVN) such as Ethernet and / or CAN. An emerging IEEE standard particularly suitable for in-vehicle networks is IEEE 802.3cg, which is a specification for 10 megabits per second (Mbits) over simple twisted pair Ethernet, allowing multiple nodes to be connected using the same twisted pair, also known as a "shared medium". The IEEE 802.3cg (10BASE-T1) project was created to enable slower devices (less than 100Mbits) to be connected in a cost-effective manner. Summary of the invention

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0007] According to one aspect of the present invention, there is provided a system, comprising:

[0008] Controller Area Network CAN controller,

[0009] Buffer unit, and

[0010] an interface unit, the interface unit being preferably a medium independent interface MII unit,

[0011] The interface unit comprises a transmission data TX input interface for receiving Ethernet frames,

[0012] wherein the interface unit is coupled to the buffer unit and is configured to transmit the Ethernet frame received through the TX input interface to the buffer unit,

[0013] wherein the buffer unit is configured to store Ethernet frames received via the interface unit,

[0014] wherein the buffer unit is coupled to the CAN controller and is configured to transmit the buffered Ethernet frames to the CAN controller,

[0015] wherein the CAN controller is configured to generate a CAN frame based on a received Ethernet frame,

[0016] The CAN controller comprises a transmission data TXD output interface for transmitting CAN frames to a CAN bus via a CAN transceiver,

[0017] wherein the CAN controller comprises a receive data RXD input interface for receiving CAN frames from a CAN bus via the CAN transceiver,

[0018] wherein the system is configured to generate a signal referred to as a TX reference rate signal referred to as a TX transfer rate representing a reference transfer rate of data of Ethernet frames to the TX input interface, depending on a fill level of the buffer unit and / or a permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames, and wherein the system comprises an interface referred to as a TX rate interface for sending the TX reference rate signal.

[0019] According to one or more embodiments, the TX reference rate signal is a clock signal.

[0020] According to one or more embodiments, the system is configured to couple the TX input interface and the TX rate interface to an Ethernet Media Access Controller MAC.

[0021] According to one or more embodiments, the interface unit is configured to receive each Ethernet frame serially at the TX input interface.

[0022] According to one or more embodiments, the system is configured to set the TX transfer rate to a first predefined transfer rate in case the fill level of the buffer unit is less than a predefined fill level referred to as a threshold fill level.

[0023] According to one or more embodiments, the buffer unit includes a reference capacity for storing at least one predefined number of Ethernet frames according to the IEEE 802.3 standard, and wherein the threshold fill level of the buffer unit corresponds to the fill level of the buffer unit with stored data, where the remaining free portion of the reference capacity is less than the data of a single Ethernet frame according to the IEEE 802.3 standard.

[0024] According to one or more embodiments, the system includes a CAN transceiver, wherein the CAN transceiver includes a CAN bus interface, the CAN bus interface is configured to couple the CAN transceiver to a CAN bus, wherein the CAN transceiver includes a TXD input interface, the TXD input interface is coupled to a TXD output interface of the CAN controller, wherein the CAN transceiver includes a RXD output interface, the RXD output interface is coupled to an RXD input interface of the CAN controller, wherein the CAN transceiver, the CAN controller and the buffer unit are integrated in a single integrated circuit IC, and wherein the buffer unit is configured such that the reference capacity is limited to storing a maximum of three Ethernet frames, specifically a maximum of a single Ethernet frame, in the buffer unit.

[0025] According to one or more embodiments, the first transfer rate is a maximum transfer rate predefined for the TX input interface.

[0026] According to one or more embodiments, the system is configured to set the TX transfer rate to a second predefined transfer rate if the fill level of the buffer unit reaches and / or exceeds the threshold fill level, wherein the second transfer rate is smaller than the first transfer rate.

[0027] According to one or more embodiments, the second transmission rate is less than 70%, 50%, 30% or 10% of the first transmission rate.

[0028] According to one or more embodiments, the second transmission rate is zero.

[0029] According to one or more embodiments, the interface unit is configured to generate a signal referred to as a TX basic rate signal, the basic rate signal indicating a maximum transmission rate referred to as a transmission control rate predefined for the TXD input interface; wherein the system comprises a unit referred to as a rate control unit; the rate control unit is coupled to the interface unit so that the TX basic rate signal is transmitted to the rate control unit; wherein the rate control unit is configured to generate the TX reference rate signal according to the TX basic rate signal depending on the filling level of the buffer unit and / or the permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames, and wherein the rate control unit is configured to transmit the TX reference rate signal via the TX rate interface.

[0030] According to one or more embodiments, the interface unit is configured to generate the TX base rate signal independently of the fill level of the buffer unit.

[0031] According to one or more embodiments, the CAN controller is coupled to the buffer unit such that the CAN controller can detect the fill level of the buffer unit, and wherein the CAN controller is coupled to the rate control unit, wherein the CAN controller is configured to control the rate control unit depending on the determined fill level and / or a permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames.

[0032] According to a second aspect of the present invention, there is provided a method for a system, the system comprising a controller area network (CAN) controller, a buffer unit and a medium independent interface (MII) unit, wherein the interface unit comprises a transmit data TX input interface for receiving Ethernet frames, wherein the interface unit is coupled to the buffer unit and is configured to transmit Ethernet frames received via the TX input interface to the buffer unit, the buffer unit is coupled to the CAN controller, the CAN controller comprises a transmit data TXD output interface for transmitting CAN frames, the CAN controller comprises a receive data RXD input interface for receiving CAN frames, the system comprises an interface referred to as a TX rate interface, the method comprises the following steps:

[0033] a) storing the Ethernet frames received via the interface unit at the buffer unit,

[0034] b) transmitting the buffered Ethernet frames from the buffer unit to the CAN controller,

[0035] c) generating a CAN frame at the CAN controller based on the received Ethernet frame,

[0036] d) transmitting the generated CAN frame via the TXD output interface,

[0037] e) generating, at the system, a signal referred to as a TX reference rate signal representing a reference transmission rate of data of Ethernet frames to the TX input interface, depending on a filling level of the buffer unit and / or a permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames, and

[0038] f) transmitting the TX reference rate signal via the TX rate interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. However, it should be noted that the drawings only illustrate typical embodiments of the present disclosure and therefore should not be considered to limit the scope of the present disclosure, so that other equally effective embodiments may be implemented. The advantages of the claimed subject matter will become apparent to those skilled in the art upon reading this description in conjunction with the accompanying drawings, wherein like reference numerals are used to indicate like elements, and wherein:

[0040] Figure 1 A simplified block diagram of an embodiment of a system is shown.

[0041] Figures 2 to 6 A simplified signal diagram is shown.

[0042] Figure 7 Another simplified block diagram of another embodiment of a system is shown.

[0043] Figure 8 A simplified flow chart illustrating an embodiment of a method. DETAILED DESCRIPTION

[0044] For a person skilled in the art, connecting two nodes of the same technology, such as two CAN nodes or two Ethernet nodes, may be only a moderate effort. Challenges may arise if a single node should have the ability to communicate with both Ethernet and CAN networks. Such a node should be able to generate CAN frames 120, 122, 124 based on Ethernet frames and vice versa.

[0045] In order to generate a differential voltage signal on the CAN bus 130 via the CAN transceiver 128 so that the differential voltage signal represents the CAN frame 120, 122, 124 to be transmitted, a so-called arbitration is required, by which access to the CAN bus 130 is allowed or denied. If access to the CAN bus 130 is allowed by arbitration, the CAN transceiver 128 can generate the previously mentioned differential voltage signal on the CAN bus 130. If access to the CAN bus 130 is denied by arbitration, the CAN transceiver 128 will stop or not start generating differential voltage signals to transmit CAN frames 120, 122, 124 from the time the denial is detected under the control of the CAN controller 102. As a result, the CAN transceiver 128 will not be able to send CAN frames 120, 122, 124 directly through the CAN bus 130 after losing arbitration. Instead, the CAN transceiver 128 will have to repeatedly enter arbitration under the control of the CAN controller 102 until access to the CAN bus 130 is granted.

[0046] Thus, a node intended to have two capabilities, namely a node to communicate with an Ethernet network and to communicate with a CAN bus 130, may include a buffer unit 104 configured to buffer at least one Ethernet frame 110, 114, 118. When the buffer unit 104 receives an Ethernet frame 110, 114, 118 to be at least partially converted into a CAN frame 120, 122, 124 in order to transmit the CAN frame 120, 122, 124 via the CAN bus 130, the received Ethernet frame 110, 114, 118 may be buffered in the buffer unit 104 until access to the CAN bus 130 is allowed. The time before access to the CAN bus 130 is allowed may take some time, so that multiple Ethernet frames 110, 114, 118 may be transmitted to the node before a first CAN frame 120 based on, for example, a first received Ethernet frame 110 is transmitted via the CAN bus 130.

[0047] A compact node size may be of interest. This may also apply to nodes intended to have two capabilities, namely, communicating with an Ethernet network and communicating with a CAN bus 130. In the prior art, the structural size of the CAN transceiver 128, which may be configured to be connected to the CAN bus 130, is usually significantly larger than the structural size of the buffer unit 104. Therefore, in order to integrate both the CAN transceiver 128 and the buffer unit 104 into the same integrated circuit IC, it may be necessary to limit the capacity of the buffer unit 104 to store data, so that the buffer unit 104 can only store a few Ethernet frames. Therefore, the buffer unit 104 may not result in a large size of the node.

[0048] Figure 1Schematically shown is an example embodiment of a system 100. The system 100 may be part of a communication device 156. The communication device 156 may be part of a node for communication in an IVN.

[0049] The system 100 includes a CAN controller 102. The CAN controller 102 may be configured according to the CAN standard such that the CAN controller 102 may support Classic CAN, CAN FD, and / or CAN XL. The CAN controller 102 includes a transmit data output interface 126, referred to as a TXD output interface 126. The TXD output interface 126 may be used to transmit CAN frames 120, 122, 124 to a CAN transceiver 128. The CAN transceiver 128 may include a transmit data input interface 142, referred to as a TXD input interface 142. In one example, the TXD output interface 126 of the CAN controller 102 is coupled to the TXD input interface 142 of the CAN transceiver 128 via a signal connection to transmit the CAN frames 120, 122, 124 from the CAN controller 102 to the CAN transceiver 128. The CAN transceiver 128 may be configured to generate a differential voltage signal representing the received CAN frames 120, 122, 124 at the CAN bus interface 140 based on the received CAN frames 120, 122, 124. The CAN bus interface 140 of the CAN transceiver 128 may be configured to couple to the signal lines of the CAN bus 130 so that the differential voltage signal may be transmitted to a remote CAN transceiver (not shown) via the CAN bus 130.

[0050] Each CAN frame 120, 122, 124 may be configured according to the CAN standard. In one example, each of the CAN frames 120, 122, 124 is configured as a CAN frame 120 and 122, 124 according to Classical CAN, CAN FD and / or CAN XL.

[0051] The CAN controller 102 includes a receive data input interface 132, also referred to as an RXD input interface 132. The RXD input interface 132 is used to receive CAN frames 120, 122, 124. The RXD input interface 132 may be coupled to a receive data output interface 144, also referred to as an RXD output interface 144, of the CAN transceiver 128. The CAN transceiver 128 may detect a differential voltage signal representing the CAN frames 120, 122, 124 via the CAN bus interface 140. The CAN transceiver 128 may be configured to transmit the received CAN frames 120, 122, 124 to the RXD input interface 132 of the CAN controller 102 via the RXD output interface 144.

[0052] The CAN controller 102 cannot directly access the CAN bus 130. Instead, the CAN controller 102 can access the CAN bus 130 (indirectly) via the CAN transceiver 128. Specifically, the CAN controller 102 can access the CAN bus 130 via a signal connection between the TXD output interface 126 and the TXD input interface 142, via another signal connection between the RXD output interface 144 and the RXD input interface 132, and via the CAN transceiver 128 and the associated CAN bus interface 140 (indirectly). The permission to access the CAN bus 130 to send CAN frames 120, 122, 124 via differential voltage signals over the CAN bus 31 is limited. According to the CAN standard, a so-called arbitration is performed by the CAN controller 102 and the CAN transceiver 128, the result of the arbitration being a positive grant state, according to which the CAN controller 102 is allowed to transmit CAN frames 120, 122, 124 on the CAN bus via the CAN transceiver 128, or a negative grant state, according to which the CAN controller 102 is not allowed to transmit CAN frames 120, 122, 124 on the CAN bus 130 via the CAN transceiver 128. For each CAN frame 120, 122, 124, the CAN controller 102 performs the above-mentioned arbitration until the CAN controller 102 reaches the positive grant state for transmitting the respective CAN frame 120, 122, 124.

[0053] The system 100 includes a unit 106, also referred to as an interface unit 106. The interface unit 106 includes a transmit data input interface 108, also referred to as a TX input interface 108. The interface unit 106 is configured to receive Ethernet frames 110, 114, 118 via the TX input interface 108. The Ethernet frames 110, 114, 118 may also be referred to as data frames 110, 114, 118 or Ethernet data frames 110, 114, 118. The interface unit 106 may be configured to couple to an Ethernet media access control (MAC) unit 138 via the TX input interface 108. The MAC unit 138 may be configured according to Ethernet standards, in particular IEEE 802.3. The IEEE 802.3 standard refers to a set of standards that define physical layer and data link layer media access control for wired Ethernet networks.

[0054] In one example, Ethernet communication refers to the 10BASE-T1S standard defined by IEEE 802.3cg. The communication will provide a plurality of communication nodes, each of which is coupled to at least one other communication node via a common communication medium such as a twisted pair to provide transmission of Ethernet frames 110, 114, 118 from one communication node to another communication node. Each Ethernet communication node may include a physical layer device, wherein the device is also referred to as a physical transceiver or an Ethernet transceiver. The Ethernet transceiver may be configured to generate a voltage signal representing an Ethernet packet on the communication medium. The Ethernet transceiver of the communication node may be coupled to a control unit configured to control access to the communication medium. The control unit may also be referred to as a MAC unit 138. The MAC unit 138 may also be referred to as a MAC controller 138 or a transmitter. The MAC unit 138 may be configured to access the communication medium via the Ethernet transceiver. The MAC unit 138 may be configured to react to signals (CRS, COL, not shown here) from the interface units 106, 152 to obtain positive access permission or negative access permission (deny access) to the communication medium.

[0055] Two communication nodes, each including an Ethernet transceiver and a MAC unit 138, may be coupled via a communication medium such that the communication medium extends from an Ethernet transceiver of one communication node to an Ethernet transceiver of another communication node. One of the transceivers may generate a voltage signal that is transmitted to the other transceiver through the communication medium, wherein the voltage signal represents an Ethernet packet. Transmission through the communication medium extending from an Ethernet transceiver to another Ethernet transceiver may be referred to as and / or configured as a medium-dependent transmission.

[0056] The Ethernet MAC 138 may include a transmit data output interface 158, which may also be referred to as a TX output interface 158. A signal connection 154 may extend from the TX output interface 158 to the TX input interface 108 of the interface unit 106. The Ethernet MAC 138 may be configured to transmit Ethernet frames 110, 114, 118 from the TX output interface 158 to the TX input interface 108 of the interface unit 106 via the signal connection 154. The transmission of the Ethernet frames 110, 114, 118 to the TX input interface 108 may be performed serially. As a result, the transmission of the Ethernet frames 110, 114, 118 on this interface may be independent of the communication medium used by the Ethernet transceiver to transmit the Ethernet frames 110, 114, 118. The interface unit 106 may also be independent of the communication mode used to transmit the Ethernet frames 110, 114, 118 over the communication medium. Therefore, the interface unit 106 may also be configured as a medium-independent interface unit 106. In one example, the interface unit 106 may be part of and / or referred to as a MII interface unit 106. However, the interface unit 106 may also be part of and / or refer to other subtypes of a media independent interface, such as a reduced media independent interface (RMII), a gigabit media independent interface (GMII), a reduced gigabit media independent interface (RGMII), a ten gigabit media independent interface (XGMII), or a serial gigabit media independent interface (SGMII).

[0057] The system 100 further includes a buffer unit 104. The buffer unit 104 may also be referred to as a buffer 104. The interface unit 106 is preferably coupled to the buffer unit 104 via a signal connection 150. The interface unit 106 may transmit an Ethernet frame 110, 114, 118 previously received by the interface unit 106 to the buffer unit 104 via a TX input interface 108. The signal connection 150 may be used for transmitting. The buffer unit 104 is configured to store at least one Ethernet frame 110, 114, 118.

[0058] The buffer unit 104 may include a predefined limited capacity for storing data, in particular data of one or more Ethernet frames 110, 114, 118. The capacity for storing data may also be referred to as a reference capacity. The Ethernet frames 110, 114, 118 are preferably configured according to the IEEE 802.3 standard. Each Ethernet frame 110, 114, 118 may include a plurality of fields. In one example, each Ethernet frame 110, 114, 118 includes a preamble field and a frame start field referred to as an SFD field. The preamble field and the SFD field may have a combined data size of 8 bytes. Each Ethernet frame 110, 114, 118 may additionally include Ethernet frame fields, the Ethernet frame fields including at least a destination address field, a source address field, a type field, a payload field, and a check field also referred to as a frame check sequence. The destination address may include 6 bytes of data, the source address may include 6 bytes of data, the type field may include 2 bytes of data, the payload field may include between 46 and 1500 bytes of data, and the check field may include 4 bytes of data. Each Ethernet frame 110, 114, 118 may have a minimum size of 64 bytes and / or a maximum size of 1518 bytes. The buffer unit 104 may be configured such that a reference capacity of the buffer unit 104 is configured to store a predefined number of at least one Ethernet frame 110, 114, 118 according to an Ethernet standard such as IEEE 802.3. The reference capacity may be limited to data of at least one predefined number of Ethernet frames 110, 114, 118. In one example, the buffer unit 104 includes a reference capacity configured to store a predefined number of Ethernet frames 110, 114, 118, each having a maximum data size. The number of Ethernet frames 110, 114, 118 may be, for example, one, two, three, or another natural number. Preferably, the number of Ethernet frames 110, 114, 118 is one or two. The small number of Ethernet frames 110, 114, 118 that buffer unit 104 can store at most provides the advantage that buffer unit 104 can be configured to be particularly compact. Such a compact design of buffer unit 104 is particularly advantageous if buffer unit 104 has the same structural size as CAN transceiver 128.

[0059] The buffer unit 104 is also coupled to the CAN controller 102. In one example, the buffer unit 104 can be coupled to the CAN controller 102 via the signal connection 134. The buffer unit 104 is configured to transmit the Ethernet frames 110, 114, 118 stored by the buffer unit 104 to the CAN controller 102. The Ethernet frames 110, 114, 118 stored by the buffer unit 104 may also be referred to as buffered Ethernet frames 110, 114, 118. Transmitting the Ethernet frames 110, 114, 118 from the buffer unit 104 to the CAN controller 102 may free up corresponding storage space of the buffer unit 104. In one example, the CAN controller 102 may be configured to read the Ethernet frames 110, 114, 118 from the buffer unit 104 via the signal connection 134, such that the reading results in transmitting the Ethernet frames 110, 114, 118 to the CAN controller 102.

[0060] The CAN controller 102 is configured to generate CAN frames 120, 122, 124 based on received Ethernet frames 110, 114, 118. In this regard, the CAN frames 120, 122, 124 correspond to CAN frames according to a CAN standard such as Classic CAN, CAN FD, or CAN XL. In one example, the CAN frame may include at least a start of frame (SOF) field, an arbitration field, a control field, a payload field, a CRC field, an acknowledgement (ACK) field, and an end of frame (EOF) field and / or be formed by at least these fields. In one example, the CAN controller 102 may be configured to generate CAN frames 120, 122, 124 based on received Ethernet frames 110, 114, 118, so that the payload field of the CAN frames 120, 122, 124 includes, in particular covers, the complete Ethernet frames 110, 114, 118 or only a portion of the Ethernet frames 110, 114, 118, such as only the payload field of the Ethernet frames 110, 114, 118. If the payload field of a CAN frame 120 , 122 , 124 includes a complete Ethernet frame 110 , 114 , 118 , the resulting communication type may also be referred to as communication of Ethernet frames 110 , 114 , 118 via CAN and / or tunneling of CAN frames 120 , 122 , 124 .

[0061] It was previously explained that the CAN controller 102 comprises a TXD output interface 126 for transmitting CAN frames 120, 122, 124 via the CAN transceiver 128, so that the CAN transceiver 128 generates a differential voltage signal on the CAN bus 130 representing the CAN frames 120, 122, 124 to be transmitted. The CAN controller 102 is configured to perform a so-called arbitration, wherein the result of the arbitration indicates whether the CAN controller 102 is positively allowed to indirectly access the CAN bus 130 to transmit the CAN frames 120, 122, 124 or whether the corresponding access is denied. Access to the CAN bus 130 may be denied if other CAN nodes are already transmitting CAN frames on the CAN bus 130 or if other CAN nodes have a higher priority for transmitting CAN frames on the CAN bus 130. Therefore, the CAN controller 102 may spend a certain amount of time, also referred to as a waiting time, to receive a positive permission through arbitration to access the CAN bus 130 via the CAN transceiver 128 to transmit the CAN frames 120, 122, 124.

[0062] In the following, reference Figures 2 to 6 , and the times T0 to T11 mentioned in this context can be converted between the various figures in a similar manner. For example, if combined with Figure 5 Introducing time T0, the same time T0 can also be applied to other Figure 2 , 3 , 4, 6.

[0063] exist Figure 5 In the figure, the process of the permission state of the CAN controller 102 is schematically shown. The permission state can be positive (thus the positive permission state A1) or negative (thus the negative permission state A2). In the positive permission state A1, the CAN controller 102 is allowed to access the CAN bus 130 via the CAN transceiver 128. In the negative permission state A2, the CAN controller 102 is not allowed (and / or denied) to access the CAN bus 130 via the CAN transceiver 128. In one example, the permission state involves a positive / negative permission to transmit a complete CAN frame 120, 122, 124 via the CAN bus 130. In one example, the permission state may be independent of the permission to participate in arbitration. The result of the arbitration is a positive permission state A1 or a negative permission state A2. As Figure 5 As shown, the negative grant state A2 exists between time T0 and time T10, so during the time period T0 to T10, the CAN controller 102 is not allowed to access the CAN bus 130 via the CAN transceiver 128. From time T10, access to the CAN bus is allowed.

[0064] exist Figure 2, an example of a transmission process of Ethernet frames 110, 114, 118 from the MAC unit 138 to the interface unit 106 is schematically shown. The MAC unit 138 can be configured to transmit a first Ethernet frame 110 to the interface unit 106 in a time period from time T1 to time T2. The first Ethernet frame 110 can be transmitted from the interface unit 106 to the buffer unit 104, wherein the buffer unit 104 stores the first Ethernet frame 110. In an example, the MAC unit 138 includes a control interface 160. The MAC unit 138 can receive a signal referred to as a TX reference rate signal via the control interface 160. The TX reference rate signal can be and / or indicates the transmission rate at which the MAC unit 138 must transmit the data of the Ethernet frames 110, 114, 118 from the TX output interface 158 to the TX input interface 108 of the interface unit 106 via the signal connection 154, also referred to as a reference transmission rate. Therefore, the MAC unit 138 can be configured to adjust the transmission rate of the data of the Ethernet frames 110, 114, 118 at the TX output interface 158 based on the TX reference rate signal so that the transmission rate (of the data of the Ethernet frames 110, 114, 118) matches the reference transmission rate.

[0065] The system 100 is configured to generate a TX reference rate signal. The system 100 further includes an interface 136 referred to as a TX rate interface 136. The system 100 is configured to transmit the TX reference rate signal via the TX rate interface 136. In one example, the TX rate interface 136 is coupled to the control interface 160 of the MAC unit 138 via a signal connection so that the system 100 can transmit the TX reference rate signal to the control interface 160 of the MAC unit 138. The TX reference rate signal can be used by the system 100 to control the data transmission rate from the Ethernet frames 110, 114, 118 to the TX input interface 108.

[0066] Previously, it was explained as an example that the buffer unit 104 can include the same structural size as the CAN transceiver 128, so that the buffer unit 104 and the CAN transceiver 128 and the CAN controller 102 can be integrated into the same integrated circuit IC. Due to this relationship, in one example, the capacity of the buffer unit 104 to store Ethernet frames 110, 114, 118 may be limited. In one example, the buffer unit 104 can be configured to store a maximum of two Ethernet frames 110, 114, 118.

[0067] refer to Figure 5, it was also previously stated that the permission state of the CAN controller 102 between time T0 and time T5 is the negative permission state A2, so that the CAN controller 102 does not have a positive permission to access the CAN bus 130 via the CAN transceiver 128. Therefore, the first Ethernet frame 110 transmitted to the buffer unit 104 via the interface unit 106 and stored by the buffer unit 104 in the time period T1 to T2 cannot be transmitted to the CAN controller 102 and / or retrieved by the CAN controller 102 in the time period T0 to T10. Therefore, the first Ethernet frame 110 must remain stored in the buffer unit 104.

[0068] During the transmission of the Ethernet frames 110, 114, 118 to the TX input interface 108, each Ethernet frame 110, 114, 118 is followed by a so-called gap 112, 116, which is also referred to as an inter-frame gap 112, 116 or an inter-packet gap 112, 116. During the gaps 112, 116, no transmission of the data of the Ethernet frames 110, 114, 118 takes place. Figure 2 , shows an example where the first gap 112 is performed directly after the transmission of the first Ethernet frame 110, and the transmission of the second Ethernet frame 114 is performed directly after the first gap 112. The transmission of the second Ethernet frame 114 may be directly followed by the second gap 116.

[0069] In one example, the buffer unit 104 includes a reference capacity for storing only two Ethernet frames 110, 114. As the first Ethernet frame 110 is transmitted to the interface unit 106 and subsequently the first Ethernet frame 110 is transmitted from the interface unit 106 to the buffer unit 104, a corresponding portion of the reference capacity of the buffer unit 104 is occupied by data of the first Ethernet frame 110. In one example, the portion of the reference capacity of the buffer unit 104 occupied by data from at least one Ethernet frame 110, 114, 118 may be referred to as a fill level of the buffer unit 104. In one example, the remaining portion of the reference capacity of the buffer unit 104 not occupied by data from at least one Ethernet frame 110, 114, 118 may be referred to as a remaining capacity of the buffer unit 104 or a free capacity of the buffer unit 104. In one example, the threshold fill level may be predefined and / or stored by the CAN controller 102. The threshold fill level of the buffer unit 104 may correspond to a (theoretical and / or predefined) fill level at which the buffer unit 104 has (theoretical) stored data, at which the remaining free part of the reference capacity, in particular the remaining capacity, is less than the amount of data of a single Ethernet frame according to the IEEE 802.3 standard. In another example, the threshold fill level of the buffer unit 104 may correspond to a (theoretical and / or predefined) fill level at which the buffer unit 104 has (theoretical) stored data, at which the remaining free part of the reference capacity is configured to store a predefined part of the data of a single Ethernet frame according to the IEEE 802.3 standard (e.g. the IEEE 802.3cg standard). For example, the predefined part may be between 1% and 99%, in particular between 10% and 80%.

[0070] exist Figure 6 , an example of a process of the filling level of the buffer unit 104 is schematically shown. Starting from time T1, the filling level of the buffer unit 104 increases. The increase in the filling level of the buffer unit is caused by the transmission of the first Ethernet frame 110 when the CAN controller 102 has the negative grant state A2. During the period T2 to T3, the filling level of the buffer unit 104 remains at the same level. The second Ethernet frame 114 is transmitted directly after the first gap 112, so that the filling level of the buffer unit 104 continues to increase from time T3. At time T11, the filling level of the buffer unit 104 reaches a predefined threshold filling level F2. By reaching the threshold filling level F2, it is clear in an example that the remaining capacity of the buffer unit 104 is so small that the interface unit 106 will no longer receive complete Ethernet frames 118 until the filling level of the buffer unit 104 drops below the threshold filling level F2 again. Only the second Ethernet frame 114 can continue to be transmitted to the interface unit 106 and indirectly to the buffer unit 104.

[0071] The system 100 is configured to generate a TX reference rate signal representing a reference transfer rate of data of Ethernet frames 110, 114, 118 to the TX input interface 108. The system 100 is configured to generate the TX reference rate signal depending on the fill level of the buffer unit 104 and / or the permission status of the CAN controller 102. The reference transfer rate may also be referred to as the TX transfer rate. The TX transfer rate is the rate at which data of the Ethernet frames 110, 114, 118 will be transferred to the TX input interface 108. If the fill level of the buffer unit 104 is low and / or less than the threshold fill level F2, the TX transfer rate may be higher, specifically a predefined maximum transfer rate. If the fill level of the buffer unit 104 reaches and / or is greater than the threshold fill level F2, the TX transfer rate may need to be smaller or smaller, specifically, become zero at the next gap 112, 116.

[0072] In one example, the CAN controller 102 can be coupled to the buffer unit 104 so that the CAN controller 102 can detect a fill level of the buffer unit 104. In one example, the system 100 and / or the CAN controller 102 can be configured to set the TX transmission rate to a first predefined transmission rate R1 if the detected fill level of the buffer unit 104 is less than a threshold fill level. The first predefined transmission rate R1 may also be referred to as the first transmission rate R1. Figure 3 , an example of a process of TX transfer rate is schematically shown. Preferably, the first transfer rate R1 is a predefined maximum allowed transfer rate for transmitting data of Ethernet frames 110, 114, 118 to the TX input interface 108. For example, the first transfer rate R1 may be 10Mbits, 25Mbits, or 100Mbits. In one example, the system 100 and / or the CAN controller 102 may be configured to set the TX transfer rate to a second predefined transfer rate R2 when the level of the detected buffer unit 104 reaches or exceeds the threshold fill level. The second predefined transfer rate R2 may also be referred to as the second transfer rate R2. The second transfer rate R2 is less than the first transfer rate R1. In one example, the second transfer rate R2 may be zero. In another example, the second transfer rate R2 may be less than 70%, less than 50%, less than 30%, or less than 10% of the first transfer rate R1.

[0073] As previously discussed, in one example, the CAN controller 102 may be coupled to the buffer unit 104 so that the CAN controller 102 may detect a fill level of the buffer unit 104. In addition, the CAN controller 102 may be coupled to the buffer unit 104 so that the CAN controller 102 may detect a transmission time of data of the Ethernet frame 114 from the interface unit 106 to the buffer unit 104. In one example, based on the detected data of the Ethernet frame 114 from the interface unit 106 to the buffer unit 104, the CAN controller 102 may be configured to detect a start time T3 at which the data of the Ethernet frame 114 is transmitted to the interface unit 106 and / or an end time T4 at which the data of the Ethernet frame 114 is transmitted to the interface unit 106. The CAN controller 102 may be configured to determine a gap 116 directly after the end time T4 at which the Ethernet frame 114 is transmitted to the interface unit 106 based on the start time T3 and / or the end time T4.

[0074] In another example, the CAN controller 102 may be (indirectly) coupled to the interface unit 106 via the buffer unit 104, so that the CAN controller 102 may detect the time when the data of the Ethernet frame 114 is transmitted to the TX input interface 108 of the interface unit 106. In one example, the CAN controller 102 may be (indirectly) coupled to the interface unit 106 via the buffer unit 104, so that the CAN controller 102 may detect the start time T3 of the Ethernet frame 114, the end time T4 of the Ethernet frame, and / or the gap 116. In one example, the CAN controller 102 may be configured to determine the time period T4 to T5 of the gap 116 based on the detected end time T4.

[0075] In one example, the CAN controller 102 may be configured to set the TX transfer rate to the second transfer rate R2 only at time T6 during the gap 116 if the fill level of the buffer unit 104 has previously reached or exceeded the threshold fill level. In one example, the CAN controller 102 may be configured to determine the gap 116 after an Ethernet frame 114 transmitted to the TX input interface 108 during which the fill level of the buffer unit 104 reached the threshold fill level F2. In one example, the CAN controller 102 may detect the time T11 at which the fill level of the buffer unit 104 reaches the threshold fill level F2. In addition, the CAN controller 102 may detect the end time T4 of the Ethernet frame 114, the data of which is transmitted to the TX input interface 108 during the transmission period T3 to T4, wherein the time T11 at which the fill level of the buffer unit 104 reaches the threshold fill level F2 is within the transmission period T3 to T4.

[0076] In one example, after the CAN controller 102 detects the time T11 at which the fill level of the buffer unit 104 reaches the threshold fill level F2, the CAN controller 102 may be configured to detect the next possible gap 116 after the time T11. In addition, the CAN controller 102 may be configured to set the TX transmission rate to the second transmission rate R2 at the time T6, wherein the time period T6 is during the detected gap 116.

[0077] As a technical effect, after detecting the time T11 and / or detecting that the fill level of the buffer unit 104 reaches the threshold fill level F2, the CAN controller 102 may first wait for the time T6 in the next gap 116 to be reached, and set the TX transfer rate to the second transfer rate R2 at the time T6 in the gap 116. Therefore, when the fill level of the buffer unit 104 reaches the threshold fill level, the TX transfer rate may not be reduced directly at the time T1, but only after the time T6. This prevents the TX transfer rate from changing during the active transmission of the data of the Ethernet frame 114, and specifically prevents the TX transfer rate from being set to zero. As a technical effect, this prevents the data of the Ethernet frame 114 from being lost.

[0078] As a further technical effect, the data of the (further) Ethernet frame 118 can be prevented from being transmitted to the interface unit 106, while the remaining capacity of the buffer unit 104 is no longer sufficient to store the data of the (further) Ethernet frame 118. Figure 6 As can be seen in FIG. 1 , the remaining capacity decreases between time T6 and time T7, so that the fill level of the buffer unit 104 reaches the threshold fill level F2 at time T7 and decreases even further thereafter. The CAN controller 102 may be configured to detect whether the fill level is less than the threshold fill level F2. If the CAN controller 102 detects that the fill level of the buffer unit 104 is less than the threshold fill level F2, the CAN controller 102 may be configured to set the TX transmission rate back to the first transmission rate R1. Figure 3 The change from the second transfer rate R2 to the first transfer rate R1 at time T7 is schematically shown.

[0079] In one example, the foregoing explanations, preferred features, technical effects and / or advantages as discussed in connection with fill levels may be combined with a permissive state of the CAN controller 102 for controlling a TX transfer rate.

[0080] In one example, the system 100 and / or the CAN controller 102 is configured to set the TX transmission rate to the first transmission rate R1 if both of the following conditions are met: (1) the fill level of the buffer unit 104 is less than a threshold fill level; and (2) the CAN controller 102 is in a positive permission state.

[0081] In one example, the system 100 and / or the CAN controller is configured to set the TX transmission rate to a second transmission rate R2 if at least one of the following two conditions is met: (1a) the buffer unit fill level has reached or exceeded a threshold fill level; (2a) the CAN controller 102 is in a denied permission state.

[0082] In one example, the CAN controller 102 may be configured to set the TX transmission rate to the second transmission rate R2 at time T6 during the gap 116 only after at least one of the following two conditions is met: (1a) the buffer unit fill level has reached or exceeded the threshold fill level; (2a) the CAN controller 102 is in a negative grant state. For condition (1a), reference is made to the previous explanation in a similar manner. In one example, the CAN controller 102 may be configured to determine the gap 116 directly after the Ethernet frame 114 is transmitted to the TX input interface 108 during the transmission that satisfies at least one of the two conditions (1a), (2a). In one example, the CAN controller may determine when the negative grant condition occurs. In one example, the negative grant state may occur if the CAN controller 102 has lost arbitration. In another example, the negative grant state may occur if the CAN controller does not have and / or loses permission to access the CAN bus 130 via the CAN transceiver 128 due to a traffic shaping strategy. Further examples of denying the CAN controller 102 access to the CAN bus 130 via the CAN transceiver 128 may be taken from the standards of Classical CAN, CAN FD and / or CAN XL.

[0083] In one example, the TX reference rate signal is a clock signal. For example, the TX reference rate signal can be and / or represent a clock frequency or clock rate at which data is sent to the TX input interface 108. The TX reference rate signal is transmitted from the system 100 to the control interface 160 of the MAC unit 138 via the TX rate interface 136, and the control interface 160 of the MAC unit 138 adjusts the transmission rate of the data from the TX output interface 158 to the TX input interface 108 of the interface unit 106 based on the clock frequency or clock rate, so that the transmission rate corresponds to the clock frequency or clock rate. In one example, in order to reduce the transmission rate of the data of the Ethernet frames 110, 114, 118 from the TX output interface 158 to the TX input interface 108, the clock rate and / or clock frequency can be reduced. The clock rate and / or clock frequency can be continuously reduced. However, it has been found that it is advantageous if the second transmission rate R2 is zero, so that the clock frequency and / or clock rate is also zero in this case. If any of the above conditions is met, the switch from the first transfer rate R1 to the second transfer rate R2 is preferably performed during the gap 116, specifically at time T6.

[0084] In one example, each Ethernet frame 110, 114, 118 transmitted from the MAC unit 138 to the TX input interface 108 of the interface unit 106 is an Ethernet frame 110 and 114, 118. As a technical effect, the system 100 can be configured to generate and transmit CAN frames 120, 122, 124 through the CAN bus 130 based on the Ethernet frames 110, 114, 118. Figure 4 An example of the process of transmitting CAN frames 120 , 122 , 124 is schematically shown.

[0085] In an example, the interface unit 106 may be configured to serially receive data of Ethernet frames 110, 114, 118 at the TX input interface 108. Thus, the data may be transmitted bit by bit. In addition, the MAC unit 138 may be configured to serially transmit the data of the Ethernet frames 110, 114, 118 from the TX output interface 158 to the TX input interface 108.

[0086] In one example, the interface unit 106 and / or the buffer unit 104 can be configured to transmit the complete Ethernet frames 110, 114, 118 (specifically, as a bundle) from the interface unit 106 to the buffer unit 104. In other words, in one example, the data of the Ethernet frames 110, 114, 118 can be transmitted in parallel from the interface unit 106 to the buffer unit 104. As a technical effect, in one example, the data of the Ethernet frames 110, 114, 118 can be transmitted from the interface unit 106 to the buffer unit 104 non-serially.

[0087] Figure 7 Another embodiment of the system 100 is schematically shown. Figure 7 The system 100, in combination with Figure 1-6 Reference is made to the foregoing explanations, preferred features, technical effects and advantages in a similar manner as explained for the system 100 .

[0088] In one example, the system 100 may further include a CAN transceiver 128. The CAN transceiver 128 includes a CAN bus interface 140. The CAN bus interface 140 may include two terminals. The CAN transceiver 128 may be configured to generate a differential voltage signal at the CAN bus interface 140, specifically between the two terminals of the CAN bus interface 140, which may represent the CAN frames 120, 122, 124. Using the differential voltage signal, the CAN frames 120, 122, 124 may be transmitted to another node (not shown) via the CAN bus 130.

[0089] The CAN transceiver 128 may include a TXD input interface 142 coupled to the TXD output interface 126 of the CAN controller 102. The CAN transceiver 128 may also include a RXD output interface 144 coupled to the TXD input interface 132 of the CAN controller 102.

[0090] In one example, the CAN transceiver 128, the CAN controller 102 and the buffer unit 104 are integrated into a single integrated circuit IC. Integrating the CAN transceiver 128 into the same IC in which the CAN controller 102 and the buffer unit 104 are integrated offers the advantage that the dimensions of the system 100 are particularly compact. In this case, however, the structural size of the integrated circuit can be determined by the structural size of the CAN transceiver 128. In one example, in order to prevent the system 100 from adopting particularly large geometric dimensions, it can be provided that the reference capacity of the buffer unit 104 is limited. For example, the reference capacity of the buffer unit 104 can be limited so that the buffer unit 104 can store a maximum of three Ethernet frames 110, 114, 118, a maximum of two Ethernet frames 110, 114, 118 or a maximum of only one Ethernet frame 110, 114, 118.

[0091] In another example, the interface unit 106 may be additionally integrated into an integrated circuit that also integrates the CAN transceiver 128 , the CAN controller 102 , and the buffer unit 104 .

[0092] In one example, the interface unit 106 may not be able to detect the level of the buffer unit 104. Figure 1 , 7 As can be seen in the embodiment of FIG. 1 , the interface unit 106 may include a (further) interface 162 , referred to as a basic interface 162 .

[0093] In one example, the interface unit 106 is configured to generate a signal referred to as a TX basic rate signal. The TX basic rate signal may be predefined and / or represent a maximum allowed transmission rate for transmitting data to the TX input interface 108. The maximum allowed transmission rate of the TX input interface 108 may also be referred to as a transmission control rate. In one example, the interface unit 106 is configured to generate the TX basic rate signal independently of the fill level of the buffer unit 104 and / or independently of the permission status of the CAN controller 102.

[0094] In one example, the system 100 includes another unit 146 referred to as a rate control unit 146. The rate control unit 146 can be coupled to the interface unit 106. In one example, the rate control unit 146 can be integrated into a signal connection 164 extending from the basic interface 162 to the TX rate interface 136. Thus, the basic rate signal is transmitted to the rate control unit 146. In one example, the rate control unit 146 is configured to generate a TX reference rate signal and transmit the TX reference rate signal to the TX rate interface 136. As a technical effect, the TX reference rate signal generated by the rate control unit 146 can be transmitted to the control interface 160 of the MAC unit 138 via the TX rate interface 136.

[0095] In one example, the rate control unit 146 is configured to generate a TX reference rate signal from the TX basic rate signal depending on the fill level of the buffer unit 104 and / or depending on the permission status of the CAN controller 102. In one example, the rate control unit 146 can be configured as a controllable switch, such as a controllable MOS FET. In one example, if the CAN controller 102 determines that the fill level of the buffer unit 104 has reached a threshold fill level, the CAN controller 102 can control the rate control unit 146 via a signal connection 148 (extending from the CAN controller 102 to the rate control unit 146) so that the rate control unit 146 specifically disconnects the signal connection 164 via the switchable switch. As a technical effect, a TX reference rate signal with a clock frequency and / or clock rate of zero is then present at the TX rate interface 136. Due to such a TX reference rate signal, the MAC unit 138 will not transmit additional data of the Ethernet frame from the TX output interface 158 to the TX input interface 108. In other words, in one example, by interrupting the signal connection 164, a second predefined transmission rate R2 can be achieved. The rate control unit 146 is configured to transmit a corresponding TX reference rate signal through the TX rate unit 146, for example, to set the TX reference rate to the first transmission rate R1. In another example, if the CAN controller 102 determines that the filling level of the buffer unit 104 is less than the threshold filling level, the CAN controller 102 can control the rate control unit 146 via the signal connection 148 so that the rate control unit 146 specifically restores the signal connection 164 via the switchable switch. As a technical effect, closing the switchable switch can restore the TX transmission rate to the first predefined transmission rate R1, which preferably corresponds to the maximum allowed transmission rate and / or the maximum transmission control rate. In other words, the first predefined transmission rate R1 can be represented by a basic rate signal. When the rate control unit 146 restores the signal connection 164, the TX reference rate signal corresponds to the basic rate signal. Subsequently, the TX reference rate signal corresponding to the basic rate signal is transmitted to the control interface 160 of the MAC unit 138. The MAC unit 138 will then resume transmitting the Ethernet frames 110, 114, 118 from the TX output interface 158 to the TX input interface 108.

[0096] As previously discussed, the interface unit 106 may not be configured to detect the level of the buffer unit 104. However, in one example, the CAN controller 102 may be configured to detect the level of the buffer unit 104. The CAN controller 102 may additionally be configured to control the rate control unit 146. Thus, in the event that the free capacity of the buffer unit 104 is too low, the system 100 may be used to temporarily prevent additional Ethernet frames from being transmitted from the MAC unit 138 to the interface unit 106. As a technical effect, the geometric size of the system 100 may be kept compact while effectively preventing the Ethernet frames 110, 114, 118 from being lost.

[0097] Figure 8 One embodiment of a method of system 100 is schematically illustrated.

[0098] For the method, reference is made to the aforementioned explanations, preferred features, technical effects and advantages in a similar manner as explained for the system 100 .

[0099] In one example, the method may include the following steps:

[0100] a) storing the Ethernet frames received via the interface unit at the buffer unit,

[0101] b) transmit the buffered Ethernet frames from the buffer unit to the CAN controller,

[0102] c) generating a CAN frame at the CAN controller based on the received Ethernet frame,

[0103] d) Transmit the generated CAN frame through the TXD output interface,

[0104] e) generating, at the system, a signal referred to as a TX reference rate signal representing a reference transmission rate of data of Ethernet frames to the TX input interface, depending on a fill level of the buffer unit and / or a permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames, and

[0105] f) Transmitting the TX reference rate signal via the TX rate interface.

[0106] Although the described exemplary embodiments disclosed herein focus on devices, systems, and methods of using the same, the present disclosure is not necessarily limited to the example embodiments shown herein.

[0107] The systems and methods described herein may be embodied, at least in part, by a computer program or by multiple computer programs, which may exist in a single computer system or across multiple computer systems in multiple forms in both activated and inactivated states. For example, the computer program may exist as a software program consisting of program instructions in source code, object code, executable code, or other formats for performing some steps. Any of the above formats may be implemented in compressed or uncompressed form on a computer-readable medium, which may include a storage device and a signal.

[0108] As used herein, the term "computer" refers to any electronic device that includes a processor, such as a general-purpose central processing unit (CPU), a special-purpose processor, or a microcontroller. A computer is capable of receiving data (input), performing a series of predetermined operations on the data, and thereby producing results (output) in the form of information or signals. Depending on the context, the term "computer" will mean (specifically) a processor or (more generally) a processor associated with a combination of related elements contained within a single housing or enclosure.

[0109] The term "processor" or "processing unit" refers to a data processing circuit, which may be a microprocessor, a coprocessor, a microcontroller, a microcomputer, a central processing unit, a field programmable gate array (FPGA), a programmable logic circuit, and / or any circuit that manipulates signals (analog or digital) based on operating instructions stored in a memory. The term "memory" refers to one or more storage circuits, such as read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and / or any circuit that stores digital information.

[0110] As used herein, a "computer-readable medium" or "storage medium" can be any component that can contain, store, convey, propagate, or transmit a computer program for use by or in conjunction with an instruction execution system, device, or apparatus. A computer-readable medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, apparatus, or propagation medium. More specific examples of computer-readable media (a non-exhaustive list) can include the following: an electrical connection with one or more wires, a portable computer disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disc read-only memory (CDROM), a digital versatile disc (DVD), a Blu-ray disc (BD), and a memory card.

[0111] It should be noted that the above embodiments have been described with reference to different subject matters. Specifically, some embodiments may have been described with reference to method claims, while other embodiments may have been described with reference to apparatus claims. However, a person skilled in the art will appreciate from the above that, unless otherwise stated, any combination of features relating to different subject matters, in particular combinations of features of method claims and features of apparatus claims, in addition to any combination of features belonging to one type of subject matter, are also considered to be disclosed with this document.

[0112] In addition, it should be noted that the drawings are schematic. In different figures, similar or identical elements are represented by the same figure mark. In addition, it should be noted that in order to provide a concise description of the illustrative embodiments, the implementation details that belong to the customary practices of technicians may not be described. It should be understood that in the development of any such implementation, as in any engineering or design project, a large number of implementation-specific decisions must be made in order to achieve the specific goals of the developer, such as complying with system-related and business-related constraints, which may be different between different implementations. In addition, it should be understood that such development work may be complex and time-consuming, but it is just a routine task for those skilled in the art to design, manufacture and produce.

[0113] Finally, it should be noted that the skilled person will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be interpreted as limiting the claim. "Comprising" does not exclude the presence of elements or steps other than those listed in the claim. The word "a" or "an" before an element does not exclude the presence of multiple such elements. The measures recited in the claims can be implemented by means of hardware comprising several different elements and / or by means of a suitably programmed processor. In a device claim that lists several components, several of these components can be implemented by the same object in hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0114] Unless stated otherwise, terms such as "first" and "second" are used to arbitrarily distinguish between the elements these terms describe. Therefore, these terms are not necessarily intended to indicate temporal or other prioritization of such elements.

Claims

1. A system, characterized in that: include: Controller Area Network CAN controller, Buffer unit, and an interface unit, the interface unit being preferably a medium independent interface MII unit, The interface unit comprises a transmission data TX input interface for receiving Ethernet frames, wherein the interface unit is coupled to the buffer unit and is configured to transmit the Ethernet frame received through the TX input interface to the buffer unit, wherein the buffer unit is configured to store Ethernet frames received via the interface unit, wherein the buffer unit is coupled to the CAN controller and is configured to transmit the buffered Ethernet frames to the CAN controller, wherein the CAN controller is configured to generate a CAN frame based on a received Ethernet frame, The CAN controller comprises a transmission data TXD output interface for transmitting CAN frames to a CAN bus via a CAN transceiver, wherein the CAN controller comprises a receive data RXD input interface for receiving CAN frames from a CAN bus via the CAN transceiver, wherein the system is configured to generate a signal referred to as a TX reference rate signal representing a reference transfer rate of data of Ethernet frames to the TX input interface, referred to as a TX transfer rate, depending on a filling level of the buffer unit and / or a permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames, and The system comprises an interface referred to as TX rate interface for transmitting the TX reference rate signal.

2. System according to the preceding claim, characterized in that The TX reference rate signal is a clock signal.

3. A system according to any of the preceding claims, characterised in that The system is configured to couple the TX input interface and the TX rate interface to an Ethernet media access controller MAC.

4. A system according to any of the preceding claims, characterised in that The interface unit is configured to receive each Ethernet frame serially at the TX input interface.

5. A system according to any of the preceding claims, characterised in that The system is configured to set the TX transfer rate to a first predefined transfer rate in case the fill level of the buffer unit is less than a predefined fill level, referred to as a threshold fill level.

6. System according to the preceding claim, characterized in that The buffer unit comprises a reference capacity for storing at least one predefined number of Ethernet frames according to the IEEE802.3 standard, and wherein the threshold fill level of the buffer unit corresponds to the fill level of the buffer unit with stored data, at which the remaining free part of the reference capacity is less than the data of a single Ethernet frame according to the IEEE 802.3 standard.

7. System according to the preceding claim, characterized in that The system comprises a CAN transceiver, wherein the CAN transceiver comprises a CAN bus interface, the CAN bus interface being configured to couple the CAN transceiver to a CAN bus, wherein the CAN transceiver comprises a TXD input interface, the TXD input interface being coupled to a TXD output interface of the CAN controller, wherein the CAN transceiver comprises a RXD output interface, the RXD output interface being coupled to an RXD input interface of the CAN controller, wherein the CAN transceiver, the CAN controller and the buffer unit are integrated in a single integrated circuit (IC), and wherein the buffer unit is configured such that the reference capacity is limited to storing a maximum of three Ethernet frames, specifically a maximum of a single Ethernet frame, in the buffer unit.

8. System according to any one of the preceding claims 5 to 7, characterized in that The first transfer rate is a maximum transfer rate predefined for the TX input interface.

9. System according to any one of the preceding claims 5 to 8, characterized in that The system is configured to set the TX transfer rate to a second predefined transfer rate if the fill level of the buffer unit reaches and / or exceeds the threshold fill level, wherein the second transfer rate is smaller than the first transfer rate.

10. System according to the preceding claim, characterized in that The second transmission rate is less than 70%, 50%, 30% or 10% of the first transmission rate.

11. The system according to claim 9, characterized in that The second transmission rate is zero.

12. A system according to any preceding claim, characterised in that The interface unit is configured to generate a signal called a TX basic rate signal, which indicates a maximum transmission rate called a transmit control rate predefined for the TXD input interface; wherein the system comprises a unit referred to as a rate control unit; the rate control unit is coupled to the interface unit such that the TX basic rate signal is transmitted to the rate control unit; wherein the rate control unit is configured to generate the TX reference rate signal according to the TX basic rate signal in dependence on the filling level of the buffer unit and / or the permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames, and wherein the rate control unit is configured to transmit the TX reference rate signal via the TX rate interface.

13. A system according to any preceding claim, characterised in that The interface unit is configured to generate the TX base rate signal independently of the fill level of the buffer unit.

14. A system according to any preceding claim, characterised in that The CAN controller is coupled to the buffer unit such that the CAN controller can detect the fill level of the buffer unit, and wherein the CAN controller is coupled to the rate control unit, wherein the CAN controller is configured to control the rate control unit depending on the determined fill level and / or a permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames.

15. A method for a system, characterized in that, The system comprises a controller area network (CAN) controller, a buffer unit and a medium independent interface (MII) unit, and wherein the interface unit comprises a transmit data TX input interface for receiving Ethernet frames, wherein the interface unit is coupled to the buffer unit and is configured to transmit Ethernet frames received via the TX input interface to the buffer unit, the buffer unit is coupled to the CAN controller, the CAN controller comprises a transmit data TXD output interface for transmitting CAN frames, the CAN controller comprises a receive data RXD input interface for receiving CAN frames, the system comprises an interface referred to as a TX rate interface, the method comprises the following steps: a) storing the Ethernet frames received via the interface unit at the buffer unit, b) transmitting the buffered Ethernet frames from the buffer unit to the CAN controller, c) generating a CAN frame at the CAN controller based on the received Ethernet frame, d) transmitting the generated CAN frame via the TXD output interface, e) generating, at the system, a signal referred to as a TX reference rate signal representing a reference transmission rate of data of Ethernet frames to the TX input interface, depending on a filling level of the buffer unit and / or a permission status of the CAN controller for accessing the CAN bus via the CAN transceiver for transmitting CAN frames, and f) transmitting the TX reference rate signal via the TX rate interface.

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