If required, the AES module can be forced to abort its current active operation and go into the IDLE state using the soft reset.
The IDLE state means the following:
- The DMAC is not actively performing DMA operations.
- The cryptographic modules are in the IDLE state.
- The key-store module does not have any keys loaded.
- The master control module is in the IDLE state.
- A soft reset must be executed in the following order:
- If DMA is used and in operation, it must be stopped.
- The master control module must be reset through the SWRESET register.
- Write the mode and length registers for the crypto core with zeroes.
The mode and length registers are:
- AESCTL
- AESDATALEN0
- AESDATALEN1
- AESAUTHLEN