If the PIT_EN bit is 1 in the S_SYSCONFIG
register, an interrupt is generated at the completion of the hash by the following steps:
- Receive last block of data (= 64
bytes). The number of data bytes defined by the S_LENGTH register is received in the
digest registers, from S_ODIGEST_A/S_IDIGEST_A to S_ODIGEST_H/S_IDIGEST_H.
- If required, apply padding to the last
block of data.
- Hash the last block of data (80 cycles
in SHA-1, SHA-384,512 mode and 64 cycles in MD5, SHA-224 and 256 modes).
- If required, add an extra 64-byte block
of data to complete the padding.
- Hash this extra block of data (80
cycles in SHA-1, SHA-384,512 mode and 64 cycles in MD5, SHA-224 and 256 modes).
- An interrupt is generated (active
low).