MATLAB: Does High CAN loads cause CANape to error out when calibrating using CCP in Embedded Target for Motorola MPC555 2.0.3 (R14SP3)

Target Support Package FM5

Under high CAN loads CANape may error out with ctr mismatch errors. This is due to CANape not being robust to duplicate messages and the 555 CAN transmit blocks may issue low priority CAN message twice under high bus load.
The CCP block by default has a transmit mode of "Queued transmission with shared buffer". This transmission mechanism may emit duplicate CAN messages when bumping low priority messages off the queue – CCP DTO messages tend to have high message ids hence low priority. These dupilicate messages will cause CANape to error out.

Best Answer

Under high CAN loads CANape may error out with ctr mismatch errors. This is due to CANape not being robust to duplicate messages.
A workaround is to set the transmit mode of the CCP block to "FIFO queued transmission with dedicated buffer". To do this follow the following instructions:
At the MATLAB command prompt:
1. Type the following:
mpc555toucan
2. Edit -> unlock library
3. Left click CAN Calibration Protocol
4. Right click -> look under mask
5. Left click DTO processing -> CCP (Termination) -> CAN Transmit -> TouCAN transmit
6. Change transmit mode from "Queued transmission with shared
buffer" to "FIFO queued transmission with dedicated buffer"
7. save library
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