Browse Prior Art Database

CRC Check/Generator Circuit Improvement

IP.com Disclosure Number: IPCOM000065399D
Original Publication Date: 1985-Dec-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Barsotti, RH Fickle, DM [+details]

Abstract

The ability of a cyclic redundancy check (CRC) generator circuit to detect data errors is improved by comparing a register's input with the register's current contents. Coding theory for CRC circuits using Galois field arithmetic to accomplish multiplication by alpha yields a probability of error detection greater than 0.996094 (for a register size of eight bits). This probability number is explained by this example: If the register is currently loaded with all zero bits, a byte of all zero bits loaded into the circuit will not change the register's contents. Because of this inability to change, the circuit cannot recognize the difference between one or many bytes of zero bits. It follows that no matter what the register's contents, there is some input data pattern which also will not change the register's contents.