42.6.3.1.1 Hashkey Generation

  • Configure CTRLA register as follows:
    1. CTRLA.STARTMODE as Manual (Auto for DMAC)
    2. CTRLA.CIPHER as Encryption
    3. CTRLA.KEYSIZE as per the key used
    4. CTRLA.AESMODE as ECB
    5. CTRLA.CTYPE as per the countermeasures required.
  • Set CTRLA.ENABLE
  • Write zero to CIPLEN reg.
  • Write the key in KEYWORD register
  • Write the zeros to INDATA reg
  • Set CTRLB.Start.
  • Wait for INTFLAG.ENCCMP to be set
  • AES Hardware generates Hash Subkey in HASHKEY register.