Parallel double error correcting code design to mitigate multi-bit upsets in SRAMs

The range of SRAM multi-bit upsets (MBU) in sub-100 nm technologies is characterized using irradiation tests on two prototype ICs, developed in 90 nm commercial processes. Results reveal that MBU, as large as 13-bit, can occur in these technologies, limiting the efficacy of conventional SEC-DED error-correcting codes (ECC). A double-error correcting (DEC) ECC implementation technique suitable for SRAM applications is presented. Results show that this DEC scheme reduces errors by 98.5% compared to only 44% reduction by conventional SEC-DED ECC.