Low power race-free state assignment of an asynchronous automaton

The problem of race-free state assignment in an asynchronous automaton is considered in a formulation where both the length of state code and the switching activity of memory elements should be minimized. To solve this problem the author uses the approach that involves consideration of the pairs of transitions between states for establishing the absence conditions for critical races. This conditions are represented as rows of a ternary matrix called the condition matrix. The state codes of a given automaton are obtained as a result of covering the condition matrix rows by compatible sets of columns. To take into account the low switching activity of memory elements, the compatible sets and correspondingly the vectors related to them are supplied with weights. So, the problem of low power race-free state assignment of an asynchronous automaton is reduced to the weighted cover problem.