A programmable power ground network optimization flow aiming at IR-drop reduction

The maximum operation frequency of integrated circuits (ICs) has reached multiple Giga Hertz. When a large number of transistors switch at the same time, high current consumption is generated. The parasitic resistance of the power ground network (PGN) combining with the high current consumption, generate significant IR-drop. This paper presents a novel PGN optimization flow, which can monitor the peak IR-drop and optimize PNG according to the demand of users. The novel flow has been implemented in Synopsys 28nm technology. When IR-drop constraints are given by users, the flow can quickly calculate out PNG optimization result. It has been proved that the presented optimization flow can measure IR-drop value accurately and optimize PGN in a short time. Experimental results demonstrate that the method has high consistency with EDA tools optimization result. IR-drop calculation error only ranges from 2% to 4%. Besides, the time consumption in this novel optimization flow is reduced 90% of the current optimization flow at least. The operation only takes one action step to complete.