21/08/2025

Inputs Needed for Static IR Analysis

o   Physical Design Database (DEF): Contains the placed locations of all cells and the layout of the power grid

o   Parasitic Resistance (RC Extraction or SPEF): Accurate resistance values for all segments of the PDN (metal wires and vias). This usually comes from an RC extraction tool run on the power grid layout (e.g., from Quantus/StarRC). Sometimes derived from LEF/tech files for early estimates.

o   Library Power Information (.lib): Specifies the average leakage power (or current) consumed by each standard cell and macro.

o   Average Switching Activity: Information about the average toggle rate or switching probability of the cells in the design. This can be:

o   A global default activity factor (e.g., 10-20% toggle rate) - less accurate.

o   Statistical averages derived from synthesis or simulation.

o   Cell-based average power calculated from libraries and potentially state probability information.

o   Power Source Locations: Coordinates and voltage values of the main power pads/bumps/sources connected to the PDN.

o   (Optional) Technology Files/each cell current characteristics defined: For EM limits and material properties if EM analysis is run concurrently.

 

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