Massively parallel switch-level simulation: a feasibility study

The feasibility of mapping the COSMOS switch-level simulator onto a computer with thousands of simple processors is addressed. COSMOS preprocesses transistor networks into Boolean behavioral models, capturing the switch-level behavior of a circuit in a set of Boolean formulas. A class of massively parallel computers and a mapping of COSMOS onto these computers are described. The factors affecting the performance of such a massively parallel simulator are discussed, including: the amount of parallelism in the simulation model, performance measures for massively parallel machines, and the impact of event scheduling on simulator performance. Compilation tools that automatically map a MOS circuit onto a massively parallel computer have been developed. Techniques for restructuring Boolean expressions for greater parallelism and mapping Boolean expressions for evaluation on massively parallel machines are described. Massively parallel switch-level simulation is illustrated by a pilot implementation on a 32k-processor Thinking Machines Connection Machine system.>