Double Modular Redundancy Design of LSI Controller for Soft Error Tolerance

Abstract

A soft error in LSI is a temporary malfunction in which signals in combinational circuits or data stored in registers are flipped. Double modular redundancy performs computation execution and data storing in duplicate, detects soft errors through comparison, and corrects errors by re-executing the computation. It is preferable in terms of LSI area and power consumption compared to triple modular redundancy. In this paper, a double modular redundancy design for LSI controllers is proposed. The register for the control step and the combinational circuit to compute the control step value are doubled to check an error in the controller. Reexecution of operations necessary to correct an error in datapath and controller is controlled using one bit signal which is also doubled for error detection and correction. The area of the proposed controller is reduced to about half of that of the conventional triple modular redundant controller.