The application security unit (ASU) is based on a MicroBlaze RISC-V processor module with several cryptographic hardware units, streaming DMA, and a key transfer pathway from the PMC. The main purpose of the ASU is to accelerate crypto operations and to act as the key storage unit for runtime applications running in the APU, RPU, or processors instantiated within the PL. The ASU firmware is loaded during the boot process by the PLM firmware. This is done in a secure manner with authentication and/or decryption.
The ASU hardware architecture is introduced in the ASU Interconnect Diagram chapter.