8b10b (10b8b)

8b10b is a coding invention developed by IBM in the early 1980s and is sometimes called 10b8b. Since it is a method of sending 8-bit "data" with 10-bit "data length", the efficiency is 80% = 20% "redundant". , 8bit (byte, octet) division (head) is understood. It can also be said that it is coding that sends the clock when returning from serial transmission to parallel. As an extension of this, more efficient coding such as 4b66b, 64b67b, and 128b130b have been developed, but the feature of 8B10B that "0 or 1 does not last long" puts less burden on the transmission line (frequency distortion). There are many cases where it is advantageous to have a secondary effect called reduction), and it is one of the factors that is still widely used today.