An efficient method to generate test vectors for combinational cell verification

In library cell verification, functionality and timing of each cell needs to be verified. Generation of an optimal and exhaustive test stimuli for each cell is a challenging problem. Though formal verification techniques are available today, vector based verification is still practiced in the industry. Here we introduce an efficient method to generate test vectors for the verification of combinational cells. The method proposed is based on the extended Gray-code concept. Generated test vectors cover all possible Single Input Change (SIC) transitions without any redundancy. An optimal implementation scheme, in terms of performance and memory, is also proposed.