Self-Repairable Multiplexer in Real Time for Fault Tolerant Systems

Abstract

Using VLSI more number of transistors can be embedded on a single chip. As the space between transistors or circuits decreasing the system or chip is more susceptible to faults. Fault tolerant systems required to avoid inaccurate results. Multiplexer is a device which selects input signals based on select signal. The existing papers deal with only self checking multiplexer. In this paper a self repairing 2:1 multiplexer which can repair permanent and transient faults is proposed. Two different architectures are proposed for self repairing multiplexer. First architecture is having additional circuitry to repair the fault in multiplexer. In second architecture the building blocks of multiplexer like OR and AND gates itself are self repairable. These self repairing multiplexer architectures can detect and repair the single and multiple faults. The proposed architectures give 100% error recovery. The circuits are simulated using Cadence tool and verified the functionality.