Custom VLSI design at the switch level is commonly applied when a chip is required to meet stringent operating requirements in terms of speed, power, or area. ATPG requires gate level models, which are verified for correctness against switch level models. Typically, test models are created manually from the switch level models---a tedious, error-prone process requiring experienced DFT engineers. This paper presents an automated flow for creating gate level test models from circuits at the switch level. The proposed flow utilizes Motorola's Switch Level Verification (SLV) tool, which employs detailed switch level analysis to model the behavior of MOS transistors and represent them at a higher level of abstraction. We present experimental results, which demonstrate that the automated flow is capable of producing gate models that meet the ATPG requirements and are comparable to manually created ones.

A chip that is required to meet strict operating criteria in terms of speed, power, or area is commonly custom designed at the switch level. Traditional techniques for verifying these designs, based on simulation, are expensive in terms of resources and cannot completely guarantee correct operation. Formal verification methods, on the other hand, provide for a complete proof of correctness, and require less effort to setup. This paper presents Motorola's Switch Level Verification (SLV) tool, which employs detailed switch level analysis to model the behavior of MOS transistors and obtain an equivalent RTL model. This tool has been used for equivalence checking at the switch level for several years within Motorola for the PowerPC, M*Core and DSP custom blocks. We focus on the novel techniques employed in SLV, particularly in the areas of pre-charged and sequential logic analysis, and provide details on the automated and integrated equivalence checking flow in which the tool is used.