An Efficient Transition Detector Exploiting Charge Sharing

Abstract

Transition detectors have been widely employed for online error and metastability detection, including in Better-Than-Worst-Case (BTWC) timing design of microprocessors that are designed to allow occasional timing errors. In such applications, the area overhead introduced by the transition detectors is a major concern because they may need to be incorporated in almost all the flip-flops in a large design. In this paper, we present a new transition detector (TDCS) which employs a novel combination of charge sharing effects and short circuit based discharge for operation to reduce more than half the circuit complexity of traditional designs. Simulation of our TDCS design shows that it can reliably achieve the same functionality as published designs with 60% fewer transistors. Furthermore, detailed corner analysis shows that our TDCS design is robust under extreme PVT variations.