AES Interrupt. Holtek HT32F5828

32-Bit Arm ®

HT32F5828

Cortex ® -M0+ MCU

AES Interrupt

The IFINT request will be generated when the input FIFO is less than or equal to 1 AES block (4 ×

32 bits). The OFINT request will be generated when there is data in the AES buffer. When the

IFINT bit is set high, an AES interrupt will be generated if the IFINT interrupt is enabled and the

AES remains enabled. When the OFINT bit is set high, an AES interrupt can also be generated if the OFINT interrupt is enabled irrespective of the AES enable/disable condition.

AES_EN

IFINT

IFINTEN

OFINT

OFINTEN

Figure 222. AES Interrupt

AES_INT

AES Initial Vector

The initial vectors (IV0 ~ 3) are not used in the ECB mode. The initial vectors are initialized in the first block of AES input data in the CBC and CTR modes. After the first AES block of input data, the values of the initial vectors will be updated by hardware automatically for the next block of

AES input data. The initial vectors in the CTR mode contain nonce, initial vector and counter. The counter will be increased by 1 after every AES data block action.

Nonce ( 32 bits )

Initial Vector

( 64 bits )

Counter ( 32 bits )

IV0

IV1, 2

IV3

Figure 223. Initial Vector for CTR Mode

Rev. 1.00 628 of 637 December 28, 2020