I was thinking it would be good to put in some runtime code in the DMA ISR to verify ping-pong buffers are correct i.e. the just DMA updated serial receive buffer is the next to be processed and sent to the transmit serial port by DMA. However, if the DMA ISR reads e.g. pCPSP0A, the DMA gets really screwed up. Is there any safe way at runtime to verify the DMA is running with correct buffer synchronization?