Timing analysis of combinational circuits using ADDs

Abstract

This paper presents a symbolic algorithm to perform timing analysis of combinational circuits which takes advantage of the high compactness of representation of the Algebraic Decision Diagrams (ADDs). The procedure we propose, implemented as on extension of the SIS synthesis system, is able to provide more accurate timing information than any other method presented so far; in particular, it is able to compute and store the true delay of the gate-level representation of the circuit for all possible input vectors, as opposed to the traditional methods which consider only the worst-case primary inputs combination. Furthermore, the approach does not require any explicit false path elimination. The information calculated by the timing analyzer has several practical applications such as determining the sets of critical input vectors, critical gates, and critical paths of the circuit, which may be efficiently used in the process of resynthesizing the network for low-power consumption.<>