21/08/2025

What if cells are low drive strength and no space for decaps to fix IR?

We have dynamic IR issue where specific location; cells are already low drive strength and no space to add decaps. We can still reduce IR by following ways:

o   Improve PDN: add extra stripes or vias in that region if possible.

o   Change in switching window: Analyze the switching activity. If many cells (even low-drive ones) in the area switch simultaneously causing the droop, try to introduce small timing delays on non-critical paths feeding into this region to slightly spread out the switching events over time. This reduces the peak current demand at any single instant.

o   VT Swapping (Higher Vt): if there are some LVT cells contributing to the switching current in the region, swapping them to higher Vt (SVT/HVT)

o   Re-evaluate Floorplan/Placement:

 

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