Run-time error detection in arrays based on the data-dependency graph

ITRED (input-driven time-redundancy error detection), a methodology based on dependency graphs for doing concurrent run-time error detection in systolic arrays and wavefront processors, is described. It combines the projection method of deriving systolic arrays from dependency graphs with the idea of input-triggered testing. Tests are triggered by inserting special symbols in the input, and so the approach gives the user flexibility in trading off throughput for error coverage. Correctness of timing is proved at the dependency graph level. The method requires no extra processing elements and little extra hardware. The general approach is presented, and corresponding constraints on the modified dependency graphs that guarantee correctness are derived