Physical Libraries

Physical Libraries
  • Physical reference libraries contains physical information of standard, macro and pad cells which are necessary for placement and routing.
  • It will define placement unit tile details such as:
    • Height of the placement rows
    • Minimum width resolution
    • Preferred routing direction
    • Pitch of routing tracks
Physical Model or Abstract Model or Layout Model
An abstract model of the standard cell layout is used instead of the complete layout file. This will have PINs defined, so as to facilitate automatic routing by the tool as per your netlist. Synopsys ICC use FRAM views as a PnR abstract. FRAM view is a cell view that has only the PINs and metal and via blockages defined. This makes sure that the interconnection between the PINs can be routed automatically and that the routing tool will not route over existing metal/via areas thus ruling out any shorts. Cadence EDI tools use LEF views, which again has only the PINs and blockages defined. LEF is an ascii file.

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