Concurrent detection of software and hardware data-access faults

A new approach allows low-cost concurrent detection of two important types of faults, software and hardware data-access faults, using an extension of the existing signature monitoring approach. The proposed approach detects data-access faults using a new type of redundant data structure that contains an embedded signature. Low-cast fault detection is achieved using simple architecture support and compiler support that exploit natural redundancies in the data structures, in the instruction set architecture, and in the data-access mechanism. The software data-access faults that the approach can detect include faults that have been shown to cause a high percentage of system failures. Hardware data-access faults that occur in all levels of the data-memory hierarchy are also detectable, including faults in the register file, the data cache, the data-cache TLB, the memory address and data buses, etc. Benchmark results for the MIPS R300D processor executing code scheduled by a modified GNU C Compiler show that the new approach can concurrently check a high percentage of data accesses, while causing little performance overhead and little memory overhead.