Signature-monitoring technique based on instruction-bit grouping

A new concurrent error-detection scheme monitors the signatures in online detection of instruction memory and control flow errors caused by transient and intermittent faults. The proposed signature-monitoring technique is based on the grouping of column bit information of instructions in a block to produce the block signature. The grouping size that represents the number of bits in a group could affect the fault coverage. It is shown that the fault coverage of a three-bit grouping scheme is better than that of two-bit grouping, and approaches to 1.0. The issue of the effect of state assignment on fault coverage is discussed. A methodology is given that can be used to select a near-optimal state assignment that guarantees a near-optimal fault coverage among all possible state assignments. A software-based simulation is conducted to justify the near-optimal state selected and validate the effectiveness of the proposed techniques. The proposed schemes are implemented in VHDL and hardware-based fault simulations running several benchmark programs verify the results obtained. Comparisons between various schemes are conducted.