STMicroelectronics /STM32G0C1 /AES /AES_DOUTR

Output data word This read-only bitfield fetches a 32-bit output buffer. A four-fold sequential read of this bitfield, upon the computation completion (CCF set), virtually reads a complete 128-bit block of output data from the AES peripheral. Before reaching the output buffer, the data produced by the AES core are handled by the data swap block according to the DATATYPE[1:0] bitfield. Data weights from the first to the fourth read operation are: [127:96], [95:64], [63:32], and [31:0]. The data signification of the output data block depends on the AES operating mode:

• Mode 1 (encryption): ciphertext
• Mode 2 (key derivation): the bitfield is not used (AES_KEYRx registers used for output)
• Mode 3 (decryption) and Mode 4 (key derivation then single decryption): plaintext The data swap operation is described in page 499.