The AES engine can accept up to 64 bytes of input data (16 32-bit words) and can hold up to 64 bytes of output data at a time (for a total of 128 bytes of buffered data). Bits 12-13 and 14-15 in AES_CNT configure the DMA request for the relevant FIFO (see above).
The input data for the AES crypto operation is written to AES_WRFIFO, the output data is read from AES_RDFIFO.
The input data for the AES crypto operation is written to AES_WRFIFO, the output data is read from AES_RDFIFO.