Analysis of soft error rates in combinational and sequential logic and implications of hardening for advanced technologies

Previous results and models have predicted that combinational logic errors would dominate over flip-flop errors for the past few technology nodes. However, recent experimental results show very little contribution from combinational-logic soft errors to overall soft-error rates. A model that explains the soft error rates as a function of frequency is developed to account for the inconsistency in observed data. Implications for hardening against soft errors for advanced technologies are discussed.