7.4.4.3.1 Manual Mode
The sequence is as follows:
- Write TDES_MR with all required fields, including but not limited to SMOD and OPMOD.
- Write the 64-bit key(s) in TDES_KEYxWRy or the Private Key internal register, depending on whether one, two or three keys are required.
- Write the initialization vector (or counter) in TDES_IVRx.Note: TDES_IVRx concern all modes except ECB.
- 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.
- 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.
- Set the START bit in the TDES Control Register (TDES_CR) to begin the encryption or decryption process.
- 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.
- When the software reads a TDES_ODATARx, TDES_IER.DATRDY is
automatically cleared.
Table 7-6. 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