ABSTRACT
5B6B line code is recommended as a universal optical communications system used in line code by CCITT, also is the most common line code in optical fiber transmission system . 5B6B line code has many advantages: the code rate is not increase very much, facilitate error code monitoring in business situations, and it is is often used the world four or five times of optical fiber transmission system.
Based on the analysis of the 5B6B encoding and decoding, this paper puts forward a method based on programmable logic devices to implements 5B6B plait coding, giveing the hardware design and software design process and circuit 5B6B encoder and decoder simulation waveform. This method makes the hardware design simple, operation fast, low cost etc. At the same time as the programming can be repeated on CPLD,we can modify it on-line, it's easy to debug and operatie.