50This interrupt is raised only if the message FIFO is actually writable by software, i.e., if all of the following conditions are met:
51i) The KMAC block is not exercised by a hardware application interface.
52ii) The SHA3 block is in the Absorb state.
53iii) Software has not yet written the Process command to finish the absorption process.
54For the interrupt to be raised, the message FIFO must also have been full previously.
55Otherwise, the hardware empties the FIFO faster than software can fill it and there is no point in interrupting the software to inform it about the message FIFO being empty. */