Systems and methods for implementing a switched controller area network
Systems, methods, and apparatuses are described herein for implementing a switched Controller Area Network (“CAN”). In some embodiments, control circuitry of a bridge may receive a CAN message. The control circuitry may identify a first plurality of nodes to which the CAN message is addressed by comparing a virtual CAN bus identifier of the CAN message to entries of a virtual CAN bus lookup table, and may identify a second plurality of nodes to which the CAN message is addressed by comparing a message identifier (“ID”) of the CAN message to entries of a message ID lookup table. The control circuitry may perform a logical AND operation between the first plurality of nodes and the second plurality of nodes, and may transmit the CAN message to a node that satisfies the logical AND operation.
1. A method for implementing a switched Controller Area Network (“CAN”), the method comprising:
receiving, at a bridge, a CAN message;
identifying a first plurality of nodes to which the CAN message is addressed by comparing a virtual CAN bus identifier of the CAN message to entries of a virtual CAN bus lookup table;
identifying a second plurality of nodes to which the CAN message is addressed by comparing a message identifier (“ID”) of the CAN message to entries of a message ID lookup table;
performing a logical AND operation between a first set of data fields corresponding to the first plurality of nodes and a second set of data fields corresponding to the second plurality of nodes to identify a data field that belongs to both the first set and the second set; and
transmitting the CAN message to a node that corresponds to the identified data field from the logical AND operation.
2. The method of claim 1 , wherein the CAN message is a broadcast message, and wherein the logical AND operation converts the broadcast message to a switched message.
3. The method of claim 2 , wherein the logical AND operation converts the broadcast message to the switched message by eliminating all but one node to which the CAN message is to be transmitted.
4. The method of claim 1 , wherein each entry of the entries of the virtual CAN bus lookup table comprises a data field of an address, wherein the data field is formed by a number of bits equal to a number of CAN nodes connected to the bridge, and wherein each bit represents whether a given node of the nodes connected to the bridge forms a part of a virtual CAN bus.
5. The method of claim 1 , wherein each entry of the entries of the message ID lookup table comprises a data field of an address, wherein the data field comprises a data field formed by a number of bits equal to a number of CAN nodes connected to the bridge, and wherein each bit represents whether a given node of the nodes connected to the bridge is programmed to accept the message ID.
6. The method of claim 1 , wherein the bridge comprises a CAN controller and an Auto Bridge Ethernet (“ABE”) module, wherein receiving, at the bridge, the CAN message comprises receiving the CAN message at the CAN controller in a CAN protocol, and wherein the method further comprises:
encapsulating, using the CAN controller, the CAN message using an Ethernet protocol;
looping the encapsulated CAN message back to the CAN controller through the ABE; and
identifying the virtual CAN bus identifier and the message ID of the CAN message from the looped back encapsulated CAN message.
7. The method of claim 1 , wherein the CAN message is received from an Electronic Communications Unit (“ECU”) of a node, wherein the CAN message is addressed to other ECUs of the node, and wherein transmitting the CAN message to the node that satisfies the logical AND operation comprises:
determining, based on the logical AND operation, whether the CAN message is addressed to another ECU of the node; and
in response to determining that the CAN message is addressed to another ECU of the node, refraining from transmitting the CAN message.
8. The method of claim 1 , wherein the method further comprises:
receiving, at the bridge, another CAN message;
determining, using a CAN controller of the bridge, whether the another CAN message should be switched to a node different from the node from which the another CAN message was received; and
in response to determining that the another CAN message should not be switched to a node different from the node from which the another CAN message was received, dropping the another CAN message.
9. The method of claim 1 , wherein the CAN message is arbitrated using a CAN protocol until it is received by the bridge.
10. The method of claim 9 , wherein transmitting the CAN message to the node that satisfies the logical AND operation comprises transmitting the CAN message using a best efforts protocol.
11. A system for implementing a switched Controller Area Network (“CAN”), the system comprising:
a plurality of nodes; and
a bridge, wherein the bridge is coupled to the plurality of nodes, wherein the bridge comprises memory, and wherein the bridge comprises control circuitry configured to:
receive a CAN message;
identify a first plurality of nodes to which the CAN message is addressed by comparing a virtual CAN bus identifier of the CAN message to entries of a virtual CAN bus lookup table, wherein the virtual CAN bus lookup table is stored in the memory;
identify a second plurality of nodes to which the CAN message is addressed by comparing a message identifier (“ID”) of the CAN message to entries of a message ID lookup table, wherein the message ID lookup table is stored in the memory;
perform a logical AND operation between a first set of data fields corresponding to the first plurality of nodes and a second set of data fields corresponding to the second plurality of nodes to identify a data field that belongs to both the first set and the second set; and
transmit the CAN message to a node that corresponds to the identified data field from the logical AND operation.
12. The system of claim 11 , wherein the CAN message is a broadcast message, and wherein the logical AND operation converts the broadcast message to a switched message.
13. The system of claim 12 , wherein the logical AND operation converts the broadcast message to the switched message by eliminating all but one node to which the CAN message is to be transmitted to.
14. The system of claim 11 , wherein each entry of the entries of the virtual CAN bus lookup table comprises a data field of an address, wherein the data field is formed by a number of bits equal to a number of CAN nodes connected to the bridge, and wherein each bit represents whether a given node of the nodes connected to the bridge forms a part of a virtual CAN bus.
15. The system of claim 11 , wherein each entry of the entries of the message ID lookup table comprises a data field of an address, wherein the data field comprises a data field formed by a number of bits equal to a number of CAN nodes connected to the bridge, and wherein each bit represents whether a given node of the nodes connected to the bridge is programmed to accept the message ID.
16. The system of claim 11 , wherein the bridge comprises a CAN controller and an Auto Bridge Ethernet (“ABE”) module, wherein receiving, at the bridge, the CAN message comprises receiving the CAN message at the CAN controller in a CAN protocol, and wherein the control circuitry of the bridge is further configured to:
encapsulate, using the CAN controller, the CAN message using an Ethernet protocol;
loop the encapsulated CAN message back to the CAN controller through the ABE; and
identify the virtual CAN bus identifier and the message ID of the CAN message from the looped back encapsulated CAN message.
17. The system of claim 11 , wherein the CAN message is received from an Electronic Communications Unit (“ECU”) of a node, wherein the CAN message is addressed to other ECUs of the node, and wherein the control circuitry of the bridge is further configured, when transmitting the CAN message to the node that satisfies the logical AND operation, to:
determine, based on the logical AND operation, whether the CAN message is addressed to another ECU of the node; and
in response to determining that the CAN message is addressed to another ECU of the node, refrain from transmitting the CAN message.
18. The system of claim 11 , wherein the control circuitry of the bridge is further configured to:
receive another CAN message;
determine, using a CAN controller of the bridge, whether the another CAN message should be switched to a node different from the node from which the another CAN message was received; and
in response to determining that the another CAN message should not be switched to a node different from the node from which the another CAN message was received, drop the another CAN message.
19. The system of claim 11 , wherein the CAN message is arbitrated using a CAN protocol until it is received by the bridge.
20. The system of claim 19 , wherein transmitting the CAN message to the node that satisfies the logical AND operation comprises transmitting the CAN message using a best efforts protocol.