oRequirement Analysis: Understand the power consumption estimate of the design (static and dynamic), voltage levels required, number of power domains, IR drop targets, and EM limits.
- Define Structure: Design the hierarchy of the PDN, typically involving:
- Power Pads/Bumps
- Power Rings
- Power Stripes:
- Power Rails
Calculate Widths/Spacing: Determine the required width and spacing of rings and stripes based on current density requirements
Layer Assignment: Assign specific metal layers for rings, horizontal stripes, and vertical stripes.
Implementation: Use PnR tool commands to create the rings, stripes, rails, and connect them with power vias.
Verification: Perform IR drop (static/dynamic) and EM analysis to verify the PDN meets the design requirements.
Commands (Tool Specific): The exact commands depend on the PnR tool:
Innovus: addRing, addStripe, editPowerVia, setDesignMode -powerPlanning, sroute (special route for rails).
ICC2: create_pg_* commands (e.g., create_pg_ring, create_pg_mesh_pattern, create_pg_stripe_pattern), set_pg_strategy, compile_pg.
oRings, Stripes, Grids: https://vlsiweb.com/power-plan/