Slack matching mode-based asynchronous circuits for average-case performance

Abstract

This paper addresses the problem of slack matching conditional asynchronous circuits for average-case performance. The behavior of the circuit is modeled using a Markov chain which governs switching between distinct modes of operations with potentially different performance requirements. Given the probability of mode switchings and desired cycle times for each mode, a minimum number of slack-matching buffers is inserted into the circuit such that an upper bound on the overall average cycle time is achieved. The problem is formulated as a Mixed Integer Linear Program and solved through relaxation. Experimental results on a new benchmark of circuits show a significant savings of slack matching buffers compared with the traditional approach and illuminate the type of circuits for which this new formulation is most beneficial.