59.4.3.1 Manual Mode

The sequence is as follows:

1. Write AESB_MR with all required fields, including but not limited to SMOD and OPMOD.
2. Write the 128-bit key in the Key registers (AESB_KEYWRx).
3. Write the initialization vector (or counter) in the Initialization Vector registers (AESB_IVRx).
   Note: The Initialization Vector registers concern all modes except ECB.
4. Set DATRDY (Data Ready) in the AESB Interrupt Enable register (AESB_IER) depending on whether an interrupt is required, or not, at the end of processing.
5. Write the data to be encrypted/decrypted in the authorized Input Data registers (see the table below).

   Table 59-1. Authorized Input Data Registers

   Operating Mode	Input Data Registers to Write
   ECB	All
   CBC	All
   CTR	All

6. Set the START bit in the AESB Control register (AESB_CR) to begin the encryption or decryption process.
7. When processing is complete, DATRDY in the AESB Interrupt Status register (AESB_ISR) rises. If an interrupt has been enabled by setting AESB_IER.DATRDY, the interrupt line of the AESB is activated.
8. When the software reads one of the Output Data registers (AESB_ODATARx), AESB_ISR.DATRDY is automatically cleared.