Controller area network communications using ethernet

• US 9,215,168 B2
• Filed: 12/17/2012
• Issued: 12/15/2015
• Est. Priority Date: 07/23/2012
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Kim, Yongbum, Tazebay, Mehmet, Brown, Kevin, Wagner, Manfred
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Aung, Sai
• Application Number:
  US13/716,521
• Publication Number:
  US 20140023068A1
• Time in Patent Office: 1,093 Days
• Field of Search: 370/254, 370/400, 709/220
• US Class Current: 1/1
• CPC Class Codes: H04L 12/40006 Architecture of a communication node current supply arrangements H04L12/10; intermediate storage or scheduling H04L49/90
• CPC Class Codes: H04L 12/40163 by assigning priority to messages according to a message field
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 2012/40215 Controller Area Network CAN
• CPC Class Codes: H04L 45/72 Routing based on the source address

Abstract

Systems and methods for implementing controller area network (CAN) communications between CAN nodes using Ethernet are provided. An Ethernet switch includes ports, each of which is configured to receive an Ethernet data packet (EDP) from a CAN node. Each EDP includes a CAN message, which includes an identification (ID) of a corresponding CAN node. A first port is configured to receive a first EDP and a second port is configured to receive a second EDP. The Ethernet switch also includes a controller module configured to detect a CAN conflict between the first EDP and the second EDP. The controller module is configured to select, in response to the detection of the CAN conflict, the first EDP or the second EDP based on the ID corresponding to the first EDP and the ID corresponding to the second EDP. The controller module is configured to route the selected EDP to a destination.

Claims

1. An Ethernet switch for implementing controller area network (CAN) communications between a plurality of CAN nodes, the Ethernet switch comprising:

a plurality of ports each of which is configured to receive an Ethernet data packet from a respective CAN node, each Ethernet data packet comprising a CAN message, each CAN message comprising an identification (ID) of a corresponding CAN node, the ID indicating a priority associated with the corresponding CAN node; and

a controller circuit configured to detect a CAN timing conflict between a first Ethernet data packet received at a first one of the plurality of ports at a same time as a second Ethernet data packet received at a second one of the plurality of ports,

wherein the controller circuit is configured to select, in response to the detection of the CAN conflict, the first Ethernet data packet or the second Ethernet data packet based on the ID corresponding to the first Ethernet data packet and the ID corresponding to the second Ethernet data packet, and

wherein the controller circuit is further configured to route the selected Ethernet data packet to a destination without routing the first or second Ethernet data packet that is not selected to a destination.

2. The Ethernet switch of claim 1, wherein each of the plurality of CAN nodes comprises a CAN controller and an Ethernet adaptation circuit.

3. The Ethernet switch of claim 2, wherein the Ethernet adaptation circuit of each of the plurality of CAN nodes encapsulates CAN messages in Ethernet packets.

4. The Ethernet switch of claim 1, wherein the selected Ethernet data packet is the first Ethernet data packet, and wherein the ID corresponding to the first Ethernet data packet is less than the ID corresponding to the second Ethernet data packet.

5. The Ethernet switch of claim 4, wherein the controller circuit is further configured to route the second Ethernet data packet on a transmission cycle after the first Ethernet data packet is routed.

6. The Ethernet switch of claim 1, wherein the controller circuit is further configured to determine the destination of the selected Ethernet data packet.

7. The Ethernet switch of claim 6, wherein the destination comprises a) a single one of the plurality of CAN nodes excluding the CAN node corresponding to the port that received the selected Ethernet data packet, b) two or more of the plurality of CAN nodes excluding the CAN node corresponding to the port that received the selected Ethernet data packet, or c) all of the plurality of CAN nodes excluding the CAN node corresponding to the port that received the selected Ethernet data packet.

8. The Ethernet switch of claim 1, further comprising a clock circuit coupled to the controller circuit, wherein the clock circuit is configured to generate a transmit clock, and wherein the controller circuit is configured to route the selected Ethernet data packet based on the transmit clock.

9. The Ethernet switch of claim 8, wherein the clock circuit is configured to receive a primary reference clock and to generate the transmit clock based on the primary reference clock.

10. The Ethernet switch of claim 1, wherein the controller circuit is configured to route the selected Ethernet data packet to the destination at a bandwidth supported by the destination.

11. The Ethernet switch of claim 1, wherein the controller circuit is configured to detect a CAN message error and to transmit an Ethernet fault message to one or more of the plurality of CAN nodes based on the detection of the CAN message error.

12. A controller area network (CAN) node for implementing CAN communications using Ethernet, the CAN node comprising:

a CAN circuit configured to generate a first CAN message, the first CAN message comprising a first identification (ID) of the CAN node, the ID being indicative of a priority associated with the CAN node;

an Ethernet adaptation circuit configured to generate a first Ethernet data packet based on the first CAN message and to provide the first Ethernet data packet to a transceiver for transmitting the first Ethernet data packet to a destination over an Ethernet link,

wherein the Ethernet adaptation circuit is further configured to receive a second Ethernet data packet from the transceiver, the second Ethernet data packet being detected by the transceiver over the Ethernet link, the second Ethernet data packet comprising a second CAN message, the second CAN message comprising a second ID, and

wherein the Ethernet adaptation circuit is further configured to extract the second CAN message from the second Ethernet data packet; and

a verification circuit configured to compare the first ID to the second ID and to determine that transmission of the first Ethernet data packet was successful when the the first ID matches the second ID.

13. The CAN node of claim 12, wherein the Ethernet adaptation circuit is configured to encapsulate the first CAN message as the first Ethernet data packet.

14. The CAN node of claim 12, further comprising the transceiver, wherein the transceiver is configured to transmit the first Ethernet data packet to the destination, wherein the first CAN message comprises transmission time information for transmitting the first CAN message, and wherein the transceiver is configured to transmit the first Ethernet data packet according to the transmission time information.

15. The CAN node of claim 12, wherein the Ethernet adaptation circuit is configured to detect an Ethernet fault message and provide a CAN message error to the CAN circuit based on the detection of the Ethernet fault message.

16. The CAN node of claim 12, wherein the Ethernet link comprises a shared Ethernet bus.

17. A method for implementing controller area network (CAN) communications between a plurality of CAN nodes using Ethernet, the method comprising:

receiving a first Ethernet data packet from a first CAN node of the plurality of CAN nodes, the first Ethernet data packet comprising a first CAN message, the first CAN message comprising a first identification (ID) of the first CAN node, and the first ID being indicative of a first priority associated with the first CAN node;

receiving a second Ethernet data packet from a second CAN node of the plurality of CAN nodes, the second Ethernet data packet comprising a second CAN message, the second CAN message comprising a second ID of the second CAN node, and the second ID being indicative of a second priority associated with the second CAN node;

detecting a timing conflict between the first Ethernet data packet and the second Ethernet data packet;

selecting, in response to the detection of the timing conflict, the first Ethernet data packet or the second Ethernet data packet based on the first priority indicated by the first ID and the second priority indicated by the second ID;

determining a destination of the selected Ethernet data packet; and

routing the selected Ethernet data packet to the destination.

18. The method of claim 17, wherein the selected Ethernet data packet is the first Ethernet data packet, wherein the destination is a first target location comprising a set of the plurality of CAN nodes, and wherein the method further comprises determining a second target location of the second Ethernet data packet, the second target location comprising at least one of the plurality of CAN nodes excluding the set of the plurality of CAN nodes.

19. The method of claim 18, further comprising routing the first Ethernet data packet to the first target location and the second Ethernet data packet to the second target location at the same time.

20. The method of claim 17, wherein the selected Ethernet data packet is routed to the destination over an Ethernet link, the Ethernet link comprising a shared Ethernet bus.

21. The method of claim 17, wherein the first ID is assigned exclusively to the first CAN node of the plurality of CAN nodes and the second ID is assigned exclusively to the second CAN node of the plurality of CAN nodes.