3.6.2 On-Demand Digest Check

On-demand digest check recalculates and compares digests of selected components with the stored digests. A failure of any digest results in the tamper event being triggered. A digest check failure is an indication that the programmed content currently in the device is not what was last programmed into the device and cannot be trusted and that the device must be reprogrammed. The on-demand digest check is invoked by calling digest check design system service. For more information about running system services, see PolarFire FPGA and PolarFire SoC FPGA System Services User Guide.

Digest check can also be executed over JTAG using the VERIFY_DIGEST action. This action verifies all component digests, returning PASS/FAIL for each component digest along with the digest value.

A read-endurance limit specifies how many times a digest of the FPGA fabric can be run before the long-term reliability of the FPGA configuration data could be affected. For more information about the FPGA configuration memory endurance limits, see respective PolarFire FPGA Datasheet or PolarFire SoC Datasheet.