Fault coverage analysis in monitored sequential circuits

This paper discusses the fault detection capabilities of monitored synchronous sequential circuits. Here a monitoring machine operates in lock-step with the main machine. This approach has two desirable features for fault detection. Besides the monitoring machine being less costly than the main machine, it is also not identical to it. It is shown that these features result in an improved fault coverage, of simultaneous delay faults affecting both the machines, as compared to duplication. At the same time, the hardware cost of the monitored sequential circuit is significantly lower.<>