Abstract :
FPLD architectures are often designed based on the results of experiments with "typical" benchmark circuits. For very large FPLDs, it may be difficult to obtain enough benchmark circuits to accurately evaluate an architecture. In this paper, we present a method for generating large random circuits with a fixed number of inputs, outputs, blocks, pins per cell, and approximate rent exponent. The circuits generated are used to evaluate several routability measures. We find that routability is best predicted by estimating the total wirelength in the circuit, not the mean wirelength times pins per cell.