SWCU195A December 2024 – May 2025 CC2744R7-Q1 , CC2745P10-Q1 , CC2745R10-Q1 , CC2745R7-Q1 , CC2755R10
Debug messages are stored into Rx Buffers. For debug handling three consecutive Rx buffers (e.g. #61, #62, #63) have to be used for storage of debug messages A, B, and C. The format is the same as for an Rx Buffer or an Rx FIFO element (see M_CAN User’s Manual section 2.4.2).
Advantage: Fixed start address for the DMA transfers (relative to RXBC.RBSA), no additional configuration required.
For filtering of debug messages Standard / Extended Filter Elements with SFEC / EFEC = “111” have to be set up. Messages matching these filter elements are stored into the Rx Buffers addressed by SFID2 / EFID2[5:0].
After message C has been stored, the DMA request output m_can_dma_req is activated and the three messages can be read from the Message RAM under DMA control. The RAM words holding the debug messages will not be changed by the M_CAN while m_can_dma_req is activated. The behaviour is similar to that of an Rx Buffers with its New Data flag set.
After the DMA has completed the DMA unit sets m_can_dma_ack. This resets m_can_dma_req. Now the M_CAN is prepared to receive the next set of debug messages.