Simultaneous Delay and Power Optimization in Global Placement

Delay and power minimization are two important objectives in the current circuit designs. Retiming is a very effective way for delay optimization for sequential circuits. In this paper we propose a framework for multi-level global placement with retiming, targeting simultaneous delay and power optimization. We propose GEO-P for power optimization and GEO-PD algorithm for simultaneous delay and power optimization and provide smooth wirelength, power and delay tradeoff. In GEO-PD, we use retiming based timing analysis and visible power analysis to identify timing and power critical nets and assign proper weights to them to guide the multi-level optimization process. We show an effective way to translate the timing and power analysis results from the original netlist to a coarsened sub-netlist for effective multi-level delay and power optimization. Our GEO-P achieves 27 % average power improvement and our GEO-PD provides gains in both delay and power improvement. To the best of our knowledge, this is the first paper addressing simultaneous delay and power optimization in multi-level global placement. 1