map, to see which M_CAN instances has been assigned with
DMA channel.
3.5.4.1.8.1 Filtering for Debug Messages
Filtering for debug messages is done by configuring one Standard / Extended Message ID
Filter Element for each of the three debug messages. To enable a filter element to filter
for debug messages SFEC / EFEC has to be programmed to 111. In this case fields
SFID1 / SFID2 and EFID1 / EFID2 have a different meaning. While SFID2 /
EFID2[10:9] controls the debug message handling state machine, SFID2 / EFID2[5:0]
controls the location for storage of a received debug message.
When a debug message is stored, neither the respective New Data flag nor IR[DRX] are
set. The reception of debug messages can be monitored via RXF1S[DMS].
Table 3-61. Example Filter Configuration for Debug Messages
Filter Element SFID1[10:0] EFID1[28:0] SFID2[10:9] EFID2[10:9] SFID2[5:0] EFID2[5:0]
0 ID debug message A 01 11 1101
1 ID debug message B 10 11 1110
2 ID debug message C 11 11 1111
3.5.4.1.8.2 Debug Message Handling
The debug message handling state machine assures that debug messages are stored to
three consecutive Rx Buffers in correct order. In case of missing messages the process is
restarted. The DMA request is activated only when all three debug messages A, B, C
have been received in correct order.
The status of the debug message handling state machine is signaled via RXF1S[DMS].
Chapter 3 Modular CAN (M_CAN)
MPC5777C Reference Manual Addendum, Rev. 1, 12/2015
Freescale Semiconductor, Inc. 107
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