Hamming SEC-DAED and Extended Hamming SEC-DED-TAED Codes Through Selective Shortening and Bit Placement

Abstract

Radiation particles can impact registers or memories creating soft errors. These errors can modify more than one bit causing a multiple cell upset (MCU) which consists of errors in registers or memory cells that are physically close. These MCUs can affect a single word, producing adjacent bit errors. Hamming codes are commonly used to protect memories or registers from soft errors. However, when multiple errors occur, a Hamming code may not detect them. In this letter, single-error-correction double adjacent error detection Hamming codes are presented for 16-, 32-, and 64-bit words. Additionally, single-error-correction double-error-detection triple adjacent error detection codes based on extended Hamming are presented as well. The enhanced detection is achieved by performing a selective shortening and reordering of the Hamming matrix so adjacent errors result in a syndrome that does not match that of any single error. These codes will help in the detection of MCUs in SRAM memory designs.