Soft error tolerant Infinite Impulse Response filters using reduced precision replicas

Radiation induced soft errors are a major issue in modern digital circuits. Traditional mitigation techniques like Triple Modular Redundancy (TMR) incur a large area and power overhead. This has motivated the design of ad-hoc mitigation techniques for some commonly used circuits. Among those, signal processing circuits have been widely studied. One technique proposed for Finite Impulse Response (FIR) filters is the use of reduced precision replicas to detect and correct errors. This approach significantly reduces the overhead required for protection. The use of reduced precision in FIR filters is straightforward as they do not have feedback paths that can lead to numerical problems. In this paper, the use of reduced precision replicas to protect Infinite Impulse Response (IIR) filters is studied. As IIR filters have feedback paths, the use of reduced precision poses additional challenges. In this context, a solution is proposed to avoid those potential issues. The approach is evaluated through a case study which shows its effectiveness.