Geetha Rangarajan - Synopsys
EETimes (8/27/2012 11:04 AM EDT)
At advanced technology nodes, longer wire lengths and highly resistive metal layers have led to a dramatic increase in interconnect delays. Traditional buffering and upsizing techniques to reduce interconnect delay are no longer as effective due to the area and power impact. To minimize design costs and better predict system performance, upfront and accurate pre-route parasitic estimation of interconnects is necessary during the implementation flow.
As we move to 28nm and below, metal resistance varies significantly (~5X-100X) across routing layers, providing both challenges and opportunities for accurate interconnect delay estimation. In this article, we review techniques that take advantage of resistance variation to reduce buffering and provide tighter post-route correlation to enable better performance prediction. The different techniques are compared for their benefits and limitations, and an optimal solution is proposed. We end by highlighting some results that illustrate measurable benefits from using layer-aware optimization.
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