In this case the Tx Buffers section in the Message RAM is subdivided into a set of dedicated Tx Buffers and a Tx FIFO. The number of dedicated Tx Buffers is configured by MCAN_TXBC.NDTB. The number of Tx Buffers assigned to the Tx FIFO is configured by MCAN_TXBC.TFQS. In case MCAN_TXBC.TFQS is programmed to zero, only dedicated Tx Buffers are used.
Figure 1. Example of Mixed Configuration Dedicated Tx Buffers / Tx
FIFO
Tx prioritization:
- Scan dedicated Tx Buffers and oldest pending Tx FIFO Buffer (referenced by MCAN_TXFS.TFGI)
- Buffer with lowest Message ID gets highest priority and is transmitted next