Design error diagnosis with re-synthesis in combinational circuits

A new approach is proposed for removing design errors from digital circuits, which does not use any error model. Based on a diagnostic pre-analysis of the circuit, a subcircuit suspected to be erroneous is extracted. Opposite to other known works, re-synthesis of the subcircuit need not be applied to the whole function of the erroneous internal signal in terms of primary inputs, it may stop at arbitrary nodes inside the circuit. As the subcircuits to be redesigned are kept as small as possible, the speed of the whole procedure of diagnosis and re-synthesis can be significantly increased. A formal algorithm is proposed for the whole procedure. Experimental data show the efficiency of the diagnostic pre-analysis.