35.7.4.4.1 DMA Operation

The SPI generates the following DMA requests:

• Data received (RX): The request is set when data is available in the receive FIFO or if at least RXTRHOLD data are available in the RX FIFO when FIFO operation is enabled. The request is cleared when DATA is read.
• Data transmit (TX): The request is set when the transmit buffer (TX DATA) is empty or if at least TXTRHOLD data locations are empty in the TX FIFO, when FIFO operation is enabled. The request is cleared when DATA is written.