Optimized Fault-Tolerant Buffer Design for Network-on-Chip Applications

Newest technologies of integrated circuits manufacture allow billions of transistors arranged in a single chip, which requires a communication architecture with high scalability and parallelism degree, such as a Network-on-Chip (NoC). As the technology scales down, the probability of Multiple Cell Upsets (MCUs) increases, being Error Correction Code (ECC) the most used technique to protect stored information against MCUs. NoC buffers are components that suffer from MCUs induced by diverse sources, such as radiation and electromagnetic interference. Thereby, applying ECCs in NoC buffers may come as a solution for reliability issues, although increasing the design cost and requiring a buffer with higher storage capacity. This paper proposes an optimized buffer using an Extended Hamming code to deal with MCUs and enhance the protected information storage, pursuing to reduce the area and power required for ECC implementation. We guide the optimized buffer evaluation by measuring the fault tolerance efficiency, buffer area, power overhead and performance of the proposed technique. All tests included the comparison with a non-optimal appliance of ECC in a NoC buffer. The results show the proposed technique reduces the area and power overhead in buffers with ECC and allows a considerable fault tolerance against MCUs with a small performance impact.