Multiple Cell Upset Correction in Memories Using Difference Set Codes

Error Correction Codes (ECCs) are commonly used to protect memories from soft errors. As technology scales, Multiple Cell Upsets (MCUs) become more common and affect a larger number of cells. An option to protect memories against MCUs is to use advanced ECCs that can correct more than one error per word. In this area, the use of one step majority logic decodable codes has recently been proposed for memory applications. Difference Set (DS) codes are one example of these codes. In this paper, a scheme is presented to protect a memory from MCUs using Difference Set codes. The proposed scheme exploits the localization of the errors in an MCU, as well as the properties of DS codes, to provide enhanced error correction capabilities. The properties of the DS codes are also used to reduce the decoding time. The scheme has been implemented in HDL, and circuit area and speed estimates are provided.