Knapbind: an area-efficient binding algorithm for low-leakage datapaths

Low leakage power datapaths can be synthesized using multithreshold CMOS (MTCMOS) modules. MTCMOS modules can be turned ON or OFF, using sleep signals. The controller in a digital system can be automatically synthesized to generate these sleep signals to turn OFF idle modules, thus minimizing leakage power. In order to sustain performance, the sleep transistor needs to be sized to large widths. This leads to a significant area overhead. We propose a binding algorithm, based on the 0-1 Knapsack algorithm, to selectively bind modules in a datapath to MTCMOS modules, achieving the optimizing leakage power within a given area constraint. We present results for five data dominated DSP circuits, at 100 nm technology node.