The register counts frames that are an integral number of bytes, have bad CRC and are
between 64 and 1518 bytes in length (1536 Bytes if MAC_NCFGR.MAXFS is written to '1'). This register is also incremented if a
symbol error is detected and the frame is of valid length and has an integral number
of bytes.
This register is incremented for a frame with bad FCS,
regardless of whether it is copied to memory due to ignore FCS mode (enabled by
writing MAC_NCFGR.IRXFCS=1).
This field will saturate at 0xFF and will be cleared on read.
