EFFECT OF SOFT ERROR SCRUBBING ON SINGLE-ERROR PROTECTED RAM SYSTEMS.

Summary form only given. The assessment of the reliability of coded computer memories is considered. Each row of chips in the memory is protected by a single-error-correcting double-error-detecting code, and it is desired to estimate the improvement in system mean time to failure (MTTF) due to the use of coding. Previous work of the authors which covered the case of hard errors only is extended to include the technique of soft error scrubbing. Bounds on the improvement to be gained by soft error scrubbing are derived, and it is shown that depending on the relative proportions of the interval chip failure modes, scrubbing may or may not be useful. Also derived is a reliability expression that incorporates the scrubbing interval T as a parameter.