Check-bit-reduced codewords using non-2n data bits for ECC-based self-refresh enhancement techniques in DRAMs

Error correction code (ECC) techniques have often been used to reduce the self-refresh power of dynamic random access memories (DRAMs). However, the overhead associated with the large number of check bits has prevented ECC methods from being incorporated into commercial applications. In a novel approach employed in this reported work, the number of data bits in the proposed codeword is set to have a length that is not a power of two (non-2ⁿ). Such a condition results in a substantial decrease in the number of required check bits. Compared to the use of 2ⁿ data bits in 1 Gb DRAMs, implementations that utilise the proposed codeword can achieve ECC-enhanced self-refresh schemes with 3.4 and 4.7 reductions in check bit and register overheads, respectively.