62.4.3.1 Manual Mode

The sequence is as follows:

1. Write TDES_MR with all required fields, including but not limited to SMOD and OPMOD.
2. Write the 64-bit key(s) in TDES_KEYxWRy, depending on whether one, two or three keys are required.
3. Write the initialization vector (or counter) in TDES_IVRx.
   Note: TDES_IVRx concern all modes except ECB.
4. Set DATRDY (Data Ready) in the TDES Interrupt Enable register (TDES_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 TDES_IDATARx (see the table below).
   Note: In 32-, 16- and 8-bit CFB modes, writing to TDES_IDATAR1 is not allowed and may lead to processing errors.
6. Set the START bit in the TDES Control Register (TDES_CR) to begin the encryption or decryption process.
7. When the processing completes, DATRDY in the TDES Interrupt Status register (TDES_ISR) rises. If an interrupt has been enabled by setting TDES_IER.DATRDY, the interrupt line of the TDES is activated.
8. When the software reads a TDES_ODATARx, TDES_IER.DATRDY is automatically cleared.

   Table 62-2. Authorized Input Data Registers

   Operating Mode	Input Data Registers to Write
   ECB	All
   CBC	All
   OFB	All
   CFB 64-bit	All
   CFB 32-bit	TDES_IDATAR0
   CFB 16-bit	TDES_IDATAR0
   CFB 8-bit	TDES_IDATAR0