Automated phase assignment for the synthesis of low power domino circuits

High performance circuit techniques such as domino logic have migrated from the microprocessor world into more mainstream ASIC designs. The problem is that domino logic comes at a heavy cost in terms of total power dissipation. For mobile and portable devices such as laptops and cellular phones, a high power dissipation is an unacceptable price to pay for high performance. Hence, we study synthesis techniques that allow designers to take advantage of the speed of domino circuits while at the same time to minimize total power consumption. Specifically, in this paper we present three results related to automated phase assignment for the synthesis of low power domino circuits: (1) We demonstrate that the choice of phase assignment at the primary outputs of a circuit can significantly impact power dissipation in the domino block (2) We propose a method for efficiently estimating power dissipation in a domino circuit and (3) We apply the method to determine a phase assignment that minimizes power consumption in the final circuit implementation. Preliminary experimental results on a mixture of public domain benchmarks and real industry circuits show potential power savings as high as 34% over the minimum area realization of the logic. Furthermore, the low power synthesized circuits still meet timing constraints.