16B/20B CODEC Development and Its ASIC Implementation

Abstract

16B/20B code is particularly well suited for highspeed local area networks and similar data links, where the information format consists of packets, variable in length, from about a dozen up to a several hundred 16-bit bytes. This transmission code translates each source byte into a constrained 20-bit binary sequence, which has excellent performance parameters near the theoretical limits for 16B/20B codes. The max run length is 5 and the maximum digital sum variation is 6. A very simple implementation of the code has been accomplished by partitioning the coder into 5B/6B and 3B/4B subordinate coders and by combining two 8B/20B modules side-by-side. This paper talks of 16B/20B CODEC development which is targeted to ASIC.