The application of parity checks to an arithmetic control

Abstract

As circuit costs go down and system complexity goes up, the inclusion of more built-in error detection circuitry becomes attractive. Most of today's equipment uses parity bits for detection of data transfer errors between units and within units. Error detection for arithmetic data with product or residue type encoding has been used to a limited extent. However, a particularly difficult area for error detection has been control logic. When an error occurs in the control, the machine is likely to assume a state where data is meaningless and/or recovery is impossible. Some presently known methods of checking control logic are summarized below.