calibration.txt

Extraction Rules Generation Flow for OpenRCX

This flow generates the RC tech file for OpenRCX. The RC tech file provides
resistance and capcitance tables used for RC extraction for a spesific process
corner.

The flow involves:
  A. Running OpenRCX to generate patterns layout.
    - Input: tech LEF
    - Output: patterns.def, patterns.v
    - Script: generate_patterns.tcl
    - Desc: OpenRCX generates many patterns geometries to model various types of
            capacitance and resistances models. 

  B. Running your favorite extraction tool (i.e., reference extractor) to extract 
     parasitics of the patterns layout.
    - Input: patterns.def, patterns.v (if required), and additional files
             required by the reference extractor.
    - Output: patterns.spef
    - Script: Not provided
    - Desc: Extract parasitics of the patterns generated by OpenRCX using reference 
            extractor. This step provides the parasitics of various types of
            pattern geometries as reference for per unit RC calculation.

  C. Running OpenRCX to convert patterns.spef to RC tch file.
    - Input: patterns.spef
    - Output: RC tech file
    - Script: generate_rules.tcl
    - Desc: OpenRCX takes the .spef from the reference extractor and performs
            calculation to produce capacitance and resistance table for all
            kinds of wire geometries. The output of this flow is an custom RC
            tech file for OpenRCX.

  D. Benchmarking - test the accuracy of OpenRCX on the patterns layout.
    - Input: patterns.def and RC tech file
    - Output: rcx.spef, diff_spef.out
    - Script: ext_patterns.tcl
    - Desc: Perform parasitic extraction on pattern layout for the calibration
            using the generated RC tech file. OpenRCX then compares the
            extracted parasitics with the golden parasitics extracted by the
            reference extractor.

How to run:
  1. Go to OpenRCX home directory (./OpenROAD/src/OpenRCX).
  2. cd calibration.
  3. Modify the user_env.tcl scipt in the script directory.
    - TECH_LEF: points to the directory of the tech LEF
    - PROCESS_NODE: the technology node
    - extRules: the name and the location of the OpenRCX tech file
  4. Run the executable script run.sh --> run step A through D.
    - source run.sh or
    - ./run.sh
  5. The OpenRCX RC tech file can be found in the directory set
     in the extRules variable.