Timing optimization by gate resizing and critical path identification

Due to the rapid progress in VLSI technology, the overall complexity of the chip has increased dramatically. There is a simultaneous need for more functions and higher speed in modern VLSI engineering. Therefore, use of a minimum amount of extra hardware to meet timing requirements is becoming a major issue in VLSI design. Here, we propose an efficient method for timing optimization using gate resizing. To control the hardware overhead, a minimum (or as small as possible) number of gates are selected for resizing with the aid of a powerful benefit function. To guarantee the performance of timing optimization, a modified version of PODEM, called τPODEM, ensures that each resized gate is located on at least one critical path. Thus, resizing a gate definitively reduces circuit delay. Simulation results demonstrate that our timing optimization method can efficiently reduce circuit delay with a limited amount of gate resizing