8.3.7.9.12 LON Frame Handling with the Peripheral DMA Controller

The USART can be used in association with the DMA Controller in order to transfer data directly into/from the on- and off-chip memories without any processor intervention.

The DMA uses the trigger flags, TXRDY and RXRDY, to write or read into the USART. The DMA always writes in the Transmit Holding register (FLEX_US_THR) and it always reads in the Receive Holding register (FLEX_US_RHR). The size of the data written or read by the DMA in the USART is always a byte.