Enhanced Implementations of Hamming Codes to Protect FIR Filters

Soft errors, especially those produced in harsh environments (as for example radiation), are a major concern for digital circuits. As technology shrinks, the failure probability of systems working in these environments is steadily growing. In order to tackle this issue, several design techniques are being used, which consider reliability as a key design parameter. Those based on redundancy, as Triple Modular Redundancy (TMR) and Hamming Codes, are especially popular, since they are quite straightforward to implement. However, this usually comes at a high cost, which many times is unfeasible for certain kinds of applications. Therefore, it is convenient to understand the structure and functionality of circuits in order take advantage of their inherent protection capabilities and therefore, minimize the extra redundancy. In this paper, this approach is used in order to optimize the protection of finite impulse response filters using Hamming codes.