Using RRNS Codes for Cluster Faults Tolerance in Hybrid Memories

Abstract

Hybrid CMOS/non-CMOS memories, in short hybrid memories, have been lauded as future ultra-capacity data memories. Nonetheless, such memories are going to suffer from high degree of cluster faults, which impact their reliability. This paper proposes two modified Redundant Residue Number Systems (RRNS) based error correcting codes to tolerate cluster faults in hybrid memories, namely (i) Three Non-Redundant Moduli RRNS (3NRM-RRNS) and (ii) Two Non-Redundant Moduli RRNS (2NRM-RRNS). Experimental results and analysis show that 3NRM-RRNS and 2NRM-RRNS possess competitive error correction capability to that of Reed-Solomon (RS) and conventional RRNS (C-RRNS), but at lower cost (reduced code size, lower performance penalty). E.g., for 16-bit memory 2NRM-RRNS provides a bit-wise error correction capability up to t=41.5% using 41 bits codeword, whereas RS offers only up to t=33.3% using 48 bits and C-RRNS supports up to t=31.1% using 61 bits. In addition, 2NRM-RRNS is 5.6 times faster than C-RRNS in recovering a correct data, which in turn results in higher speed decoding performance.