Low-power technology mapping for mixed-swing logic

Mixed-swing logic employs multiple power supply rails and device threshold voltages and allows us to create richer cell libraries with a wider range of power/speed tradeoffs. However, mapping onto such a library with a conventional technology mapper will not exploit the full potential of a mixed-swing methodology. To remedy this, we have developed a new technology mapping tool that specifically targets mixed-swing logic. Our approach combines (1) efficient clustering and cluster-level delay budgeting for the uncommitted logic, with (2) an exhaustive search for the optimal cover that is rendered practical by the clustering process. Power savings up to 3X have been demonstrated with our mixed-swing solutions versus single power supply implementations.