Trade-offs in execution signature compression for reliable processor systems

Abstract

As semiconductor processes scale, making transistors more vulnerable to transient upset, a wide variety of microarchitectural and system-level strategies are emerging to perform efficient error detection and correction computer systems. While these approaches often target various application domains and address error detection and correction at different granularities and with different overheads, an emerging trend is the use of state compression, e.g., cyclic redundancy check (CRC), to reduce the cost of redundancy checking. Prior work in the literature has shown that Fletcher's checksum (FC), while less effective where error detection probability is concerned, is less computationally complex when implemented in software than the more-effective CRC. In this paper, we reexamine the suitability of CRC and FC as compression algorithms when implemented in hardware for embedded safety-critical systems. We have developed and evaluated parameterizable implementations of CRC and FC in FPGA, and we observe that what was true for software implementations does not hold in hardware: CRC is more efficient than FC across a wide variety of target input bandwidths and compression strengths.