Soft Error Tolerant Quasi-Delay Insensitive Asynchronous Circuits: Advancements and Challenges

Susceptibility to soft errors caused by radiation or other noise sources is a major concern for devices operating with limited supply voltages at scaled technology nodes. These errors are occasional abnormalities that give rise to single event effects (SEE), which may corrupt the circuit functionality. Although the insensitivity to timing variations allows quasi delay insensitive (QDI) circuits to be robust against many of the radiation or noise effects that affect the timing behavior of CMOS based synchronous digital circuits, they are still susceptible to soft errors. Various error detection, mitigation, and radiation hardening schemes for QDI circuits exist in the literature. This paper provides a comprehensive overview of the existing techniques and a comparative analysis of their significance, performance, and limitations.