CRC-based forward error correction circuitry and method

A CRC (cyclic redundancy check) method for accomplishing FEC (forward error correction) in a communication system including digital transmitter circuitry and digital receiver circuitry, the method comprising:

• (a) operating a CRC (cyclic redundancy check) generator circuit in the digital transmitter circuitry on a received message to generate a first CRC code based on the message, appending the first CRC code to the message to provide a first data packet, transforming the message and the first CRC code in the first data packet to provide a second data packet in a form suitable for transmission, and transmitting the second data packet;
• (b) operating circuitry in the digital receiver circuitry to receive the transmitted second data packet;
• (c) operating a CRC verification circuit to compare a received first digital CRC code portion of the second data packet with a calculated digital CRC code based on a message portion of the second data packet possibly including an error introduced by the digital transmitter circuitry or by the digital receiver circuitry to detect existence of any error in the message portion of the second data packet, and presenting the message portion of the second data packet for further processing if no error is detected;
• and
• (d) operating a CRC-based FEC (forward error correction) circuit if an error is detected to attempt to correct the detected error without use of parity bits, and indicating that the detected error is uncorrectable if the attempt to correct it is unsuccessful, wherein said attempt to correct the detected error is based on a determination of whether the detected error affects an even number of bits or an odd number of bits.