This counter tracks frames with a CRC error detected specifically by the Rx FPGA. This appears to be a lower-level, FPGA-native CRC check distinct from the HDLC-layer check and the post-decompression check elsewhere in this table, so comparing all three helps localize exactly which processing stage in the receive chain is where corruption is first detected. If this FPGA-level counter and the HDLC CRC counter rise together while the post-decompression counter stays flat, that pattern points to the corruption originating at or before the FPGA rather than in the later decryption/decompression stage.