Another approach for verifying readback data is to compare the readback data stream to the frame data within the FDRI write in the original configuration bitstream, masking readback bits with the MSK file (see the following figure).
After sending readback commands to the device, comparison begins by aligning the beginning of the readback frame data to the beginning of the FDRI write in the BIT and MSK files. The comparison ends when the end of the FDRI write is reached.
This approach requires the least in-system storage space, because only the BIT, MSK, and readback commands must be stored.