AES hardware accelerator (AES) RM0440
1528/2126 RM0440 Rev 4
Bit 12 DMAOUTEN: DMA output enable
This bit enables/disables data transferring with DMA, in the output phase:
0: Disable
1: Enable
When the bit is set, DMA requests are automatically generated by AES during the output data
phase. This feature is only effective when Mode 1 or Mode 3 is selected through the MODE[1:0]
bitfield. It is not effective for Mode 2 (key derivation).
Usage of DMA with Mode 4 (single decryption) is not recommended.
Bit 11 DMAINEN: DMA input enable
This bit enables/disables data transferring with DMA, in the input phase:
0: Disable
1: Enable
When the bit is set, DMA requests are automatically generated by AES during the input data phase.
This feature is only effective when Mode 1 or Mode 3 is selected through the MODE[1:0] bitfield. It is
not effective for Mode 2 (key derivation).
Usage of DMA with Mode 4 (single decryption) is not recommended.
Bit 10 ERRIE: Error interrupt enable
This bit enables or disables (masks) the AES interrupt generation when RDERR and/or WRERR is
set:
0: Disable (mask)
1: Enable
Bit 9 CCFIE: CCF interrupt enable
This bit enables or disables (masks) the AES interrupt generation when CCF (computation complete
flag) is set:
0: Disable (mask)
1: Enable
Bit 8 ERRC: Error flag clear
Upon written to 1, this bit clears the RDERR and WRERR error flags in the AES_SR register:
0: No effect
1: Clear RDERR and WRERR flags
Reading the flag always returns zero.
Bit 7 CCFC: Computation complete flag clear
Upon written to 1, this bit clears the computation complete flag (CCF) in the AES_SR register:
0: No effect
1: Clear CCF
Reading the flag always returns zero.
Bits 6:5 CHMOD[1:0]: Chaining mode selection, bits [1:0]
This bitfield, together with the bit CHMOD[2] forming CHMOD[2:0], selects the AES chaining mode:
000: Electronic codebook (ECB)
001: Cipher-Block Chaining (CBC)
010: Counter Mode (CTR)
011: Galois Counter Mode (GCM) and Galois Message Authentication Code (GMAC)
100: Counter with CBC-MAC (CCM)
others: Reserved
Attempts to write the bitfield are ignored when the EN bit of the AES_CR register is set before the
write access and it is not cleared by that write access.
To Next Page
Loading...
Need help?
General
