Gate sizing in MOS digital circuits with linear programming

A solution is presented to tune the delay of a circuit composed of cells to a prescribed value, while minimizing power consumption. The tuning is performed by adapting the load drive capabilities of the cells. This optimization problem is mapped onto a linear program, which is then solved by the simplex algorithm. This approach guarantees to find the global optimum, and has proven feasible for circuits of up to several thousand cells. The method can be used with any convex delay model. Results show that circuits can be speeded up by a factor of 2 at a cost of only 10 to 30% of extra power.< >