Patent ID: 7155378

Claim:
A system for providing ad hoc verification for a simulation, comprising: a golden record of state values for a plurality of cycles of the simulation, wherein the plurality of cycles defines a block of cycles ending with a breakpoint; an instrumented instruction set simulator configured to obtain a first state value and a second state value of the simulation; a checksum unit configured to generate a cumulative record of state values for the plurality of cycles using the first state value and the second state value; a comparator configured to compare the cumulative record of state values with the golden record of state values; an instruction set simulator simulation comprising a plurality of instructions for performing the simulation using the instrumented instruction set simulator; a companion simulator and a reference simulator performing a secondary cycle-by-cycle simulation for the block of cycles using the instruction set simulator simulation if the comparator generates a predetermined value of a comparison result; and a diagnostic output device for generating diagnostic output using a result of the secondary simulation.