Receive FIFO for direct mode
| DIRECT_RX | With each byte clocked out on the serial interface, one byte will simultaneously be clocked in, and will appear in this FIFO. The serial interface will stall when this FIFO is full, to avoid dropping data. When 16-bit data is pushed into the TX FIFO, the corresponding RX FIFO push will also contain 16 bits of data. The least-significant byte is the first one received. |