32-bit Input Data registers load the data block used for hash
processing.
These registers are write-only to prevent reading of input data by another
application.
SHA_IDATAR0 corresponds to the first word of the block, SHA_IDATAR15 to
the last word of the last block in case SHA algorithm is set to SHA1, SHA224, SHA256,
or SHA_IODATAR15 to the last word of the block if SHA algorithm is SHA384 or SHA512
(see SHA Input/Output Data Register x).
SHA_IDATARx can be also written to configure the hash result of the previous fragment
of a message when starting the processing of the next fragment when the SHA has
processed another message in between fragments.
