Debugging processors with advanced features by reprogramming LUTs on FPGA

Modeling Unknown Values in Test and Verification

“…Apart from the approach in [32,33], the diagnosis and rectification problem respecting local interfaces has not been addressed in the literature so far. In [34,35], e. g., rectifications are computed, but they are allowed to depend on arbitrary signals in the circuit.…”

“…(Moreover, in contrast to [35], [34] uses a SAT formulation to compute rectifications for a given set of counterexamples only, without considering correctness for all possible inputs.) The approach of [32,33] solves the PEC problem exactly, but it is restricted to problem instances of moderate sizes, since the black boxes are replaced by function tables using an exponential number of Boolean variables. A more efficient complete approach, based on solving dependency quantified Boolean formulas (DQBFs) was presented in [36].…”