Sel 76-037 Error Correction by Alternate-data4 Retry

A new technique for low-cost error correction in computers is the alternate-data retry (ADR). An ADR is initiated by the detec,* * . tion of an error in the initial execution of an operation. The ADR is a re-execution of the operation, but with an alternate representation of the initial data. The choice of the alternate representation and the design of the processing circuits combine to insure that even an error due to a permanent fault is not repeated during retry. Error-correction is provided at a hardware cost comparable to that of a conventional retry capability. Sufficient conditions 'are given for the design of circuits with an ADR capability. The application of an ADR capability to memory and to the data paths of a processor is illustrated.