The Data IN (DIN) DMA engine transfers data into the CRYPTOCELL subsystem and its various cryptographic engines.
The DIN DMA engine provides a comprehensive interface for to facilitate the transfer of data from the CPU or memory to the cryptographic engines. It includes a variety of registers that control direct data buffering, DMA operations, and data flow management.
Maximum DMA transaction size is limited to 216-1 bytes. If a DMA transaction is configured with a payload size above the maximum DMA transaction size limit, the DMA engine must be reset before being functional again using register DIN_SW_RESET.
The flow demonstrated in Cryptographic flow shows how the DIN DMA engine is configured to provide data to the AES engine using registers SRC_MEM_ADDR and SRC_MEM_SIZE to define the input source address and number of input bytes, respectively.