Abstract

We propose to use the dominant time constant of a resistor-capacitor #RC# circuit as a measure of the signal propagation delay through the circuit. We show that the dominant time constant is a quasiconvex function of the conductances and capacitances, and use this property to cast several interesting design problems as convex optimization problems, speci#cally, semide#nite programs #SDPs#. For example, assuming that the conductances and capacitances are a#ne functions of the design parameters #which is a common model in transistor or interconnect wire sizing#, one can minimize the power consumption or the area subject to an upper bound on the dominant time constant, or compute the optimal tradeo# surface between power, dominant time constant, and area. We will also note that, to a certain extent, convex optimization can be used to design the topology of the interconnect wires. This approach has two advantages over methods based on Elmore delay optimization. First, it handles a far wide...

Citations