XC164-16 Datasheet, PDF (328/417 Pages) Infineon Technologies AG – 16-Bit Single-Chip Microcontroller with C166SV2 Core Volume 2 (of 2): Peripheral Units

XC164-16 Derivatives
Peripheral Units (Vol. 2 of 2)
TwinCAN Module
21.1.6 Gateway Message Handling
The CAN module supports an automatic information transfer between two independent
CAN bus systems without CPU interaction.
CAN Bus A
CAN Bus B
CAN
Node A
CAN
Node B
Gateway
CAN Message Object Memory
Bus Interface
CPU
MCA05485
Figure 21-15 TwinCAN Gateway Functionality
The gateway functionality is handled via the CAN message object memory shared by
both CAN nodes. Each object stored in the message memory is associated to node A or
to node B via bit NODE in the message configuration register MSGCFGn. The
information exchange between both CAN nodes can be handled by coupling two
message objects (normal gateway mode) or by sharing one common message object
(shared gateway mode).
In the following paragraphs, the gateway side receiving data frames is named “source”
(indicated by <s>) and the side transmitting the data frames, which passed the gateway,
is called “destination” (indicated by <d>). In concordance to this notation, remote frames
passing the gateway are received on the destination side and transmitted on the source
side.
The gateway function of a message object and the requested information transfer mode
are defined by bitfield MMC in the FIFO/Gateway control register MSGFGCRn.
User’s Manual
TwinCAN_X41, V2.1
21-28
V2.1, 2004-03