Host Node Configuration
The user can choose between two DMA modes by configuring the FLEX_US_LINMR.PDCM bit:
- PDCM = 1: The LIN configuration is stored in the WRITE buffer and it is written by the DMA in the Transmit Holding register FLEX_US_THR (instead of the LIN Mode register FLEX_US_LINMR). Because the DMA transfer size is limited to a byte, the transfer is split into two accesses. During the first access, the NACT, PARDIS, CHKDIS, CHKTYP, DLM and FSDIS bits are written. During the second access, the 8-bit DLC field is written.
- PDCM = 0: The LIN configuration is not stored in the WRITE buffer and it must be written by the user in FLEX_US_LINMR.
The WRITE buffer also contains the Identifier and the data, if the USART sends the response (NACT = PUBLISH).
The READ buffer contains the data if the USART receives the response (NACT = SUBSCRIBE).