Cyclic Redundancy Check (CRC)

Introduction

The CRC is a very powerful but easily implemented technique to obtain data reliability. The CRC technique is used to protect blocks of data called Frames. Using this technique, the transmitter appends an extra n- bit sequence to every frame called Frame Check Sequence (FCS). The FCS holds redundant information about the frame that helps the transmitter detect errors in the frame. The CRC is one of the most used techniques for error detection in data communications. The technique gained its popularity because it combines three advantages:

• Extreme error detection capabilities.
• Little overhead.
• Ease of implementation.

The following sections will explain the CRC more in depth:

• How the CRC algorithm works
• Implementing the CRC algorithm in hardware
• Implementing the CRC algorithm in software
• The Most used CRC polynomials