1. In a programmable logic array of the type which operates on binary data variables in an AND matrix of logic performing elements to generate product terms and supplies them to an OR matrix of logic performing elements which in turn feeds sums of these product terms into a storage means to provide those output signals in various combinations as inputs to the AND array, the improvement comprising: logic means including at least logic performing elements in the AND matrix to generate a control signal from said binary data variables and powering means responsive to said control signal to conditionally power at least a portion of one of the logic performing parts of the programmable logic array in response to said control signal.