We want to implement an audio application in which the audio data should be encrypted/decrypted via AES-256 in CTR mode. The audio processing should be done on the HiFi4 DSP of the RT600. From the block diagram (Fig.4 and Fig.5) of the RT 600 product data sheet rev 2.0 it seems that the HiFi4 DSP has no direct access to the HASH-crypt HW in order to perform the encryption/decryption of the audio data. It seems that the ARM Cortex-M33 needs to be involved here as this core has direct access the the HASH-crypt HW. This involvement of the ARM Cortex-M33 would mean additional power consumption which we would like to avoid in our application. Is my understanding correct? Is there really no way that the HiFi4 DSP can access the HASH-crypt HW? If there is a way how would this be possible (e.g. maybe indirectly via one of the DMAs)?
Hi @pascheuer ,
Yes, HASH-CRYPT AES Engine is untouchable to DSP. You have to let CM33 to control the engine to decrypt the data. Then CM33 can sleep after a data block is decrypted and be waked up by DSP next time.