On Hamming Product Codes With Type-II Hybrid ARQ for On-Chip Interconnects

We present hardware performance analyses of Hamming product codes combined with type-II hybrid automatic repeat request (HARQ), for on-chip interconnects. Input flit width and the number of rows in the product code message are investigated for their impact on the number of wires in the link, codec delay, reliability, and energy consumption. Analytical models are presented to estimate codec delay and residual flit error rate. The analyses are validated by comparison with simulation results. In a case study using H.264 video encoder in a network-on-chip environment, the method of combining Hamming product codes with type-II HARQ achieves several orders of magnitude improvement in residual flit error rate. For a given residual flit error rate requirement (e.g., 10^-20), this method yields up to 50% energy improvement over other error control methods in high-noise conditions.