Implementation conditions for delay insensitive circuits

Abstract

Designs of delay insensitive circuits must be proven correct in two different respects. First it must be demonstrated that a design meets its functional specification. Second it must be assured that it tolerates arbitrary delays in its individual components. The latter proof requires a model explicitly mentioning wire delays, whereas the former is much easier carried out in a model neglecting such delays. In this paper we show how explicit treatment of wire delays can be substituted by a set of implementation conditions imposed on a model neglecting wire delays. When the conditions are satisfied, the circuit is assured to be delay insensitive. The implementation conditions are directed towards circuits consisting of self-timed elements using delay insensitive coding for data transfer.