Why does the CRC flag not get set when a corrupted application image is made to update a an Intel® Arria® 10 or Intel Cyclone® 10 GX device using Remote Update?

During a Remote Update of Intel® Arria® 10 or Intel Cyclone® 10 GX devices using the Remote Update Intel FPGA IP, an application image may successfully load despite corrupted bytes in the bit stream, if the corrupted bytes were forced to be 0xFFFF.

This is because the CRC engine in Intel Arria 10 and Intel Cyclone 10 GX devices assumes these to be dummy bytes and ignores all 0xFFFF during the CRC check. 

This is known behavior for Intel Arria 10 and Intel Cyclone 10 GX devices. Whilst corrupting the application image with 0xFFFF will be ignored,  a single or multiple bit corruption in the application image will successfully set the CRC flag during Remote Update.