The DRE block diagram is shown in the following figure:

Figure 1. DRE block diagram

  • The DRE contains a central message storage RAM which buffers the CAN frames and the Ethernet frames

  • The Routing Control Unit assists in the transfer of received CAN frames from the MCMCAN module to the internal message RAM. The Routing Control Unit also transfers the CAN frame to the identified CAN interface for transmission

  • The ACF CAN - Ethernet Format Engine performs the translation of CAN frames to ACF frame format and vice versa

  • The CAN Transmit Routing Engine, along with a user-configured Routing Table, decides the destination CAN interface from which a CAN frame has to be transmitted. The Routing Control Unit also transfers the CAN frame to the identified CAN interface for transmission

  • The Ethernet Descriptor Handler maintains the Ethernet Transmit (Tx) and Receive (Rx) descriptors which will then be used by Ethernet DMA or the software to transmit or receive Ethernet frames

  • The Forwarding Engine, along with a user-configured Forwarding Table, decides the destination Ethernet interface(s) to which the Ethernet frame has to be forwarded