Scan-chain-based multiple error recovery in TMR systems (SMERTMR)

In this paper, we present a roll forward error recovery technique for triple modular redundancy (TMR) system based on scan-chains, called scan-chain-based multiple error recovery technique in triple modular redundancy systems (SMERTMR). This technique uses scan-chain flip-flops to detect and correct faulty modules in the presence of single or multiple transient faults. In this technique both, the errors in the output of the voter and the error due to latent faults at the input of modules are detected. The latent faults are detected by comparing the internal states of the TMR modules. Upon detection of any mismatch between the modules output, the SMERTMR system will find the faulty modules and it can correct the faulty module by copying the state of a fault-free module into the faulty modules. Upon detection of permanent fault, the system will degrade to a master/checker configuration. In this paper we are proposing SMERTMR in modify mode which is the combination of comparison and recovery mode of SMERTMR.