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The-OpenROAD-Project / OpenLane

OpenLane is an automated RTL to GDSII flow based on several components including OpenROAD, Yosys, Magic, Netgen and custom methodology scripts for design exploration and optimization.
https://openlane.readthedocs.io/
Apache License 2.0
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issues in using the floorplan core utilization command #2101

Open Ashutosh-3107 opened 3 months ago

Ashutosh-3107 commented 3 months ago

Description

Even though the default value of floorplan core utilization is 50 percent of the die area , while running the floorplan core utilization to 0.6 the core almost utilizes the entire die area which leaves very less place for routing stage

Expected Behavior

to utilize the area as set in the configuration tcl file

Environment report

open_pdks cd1748bb197f9b7af62a54507de6624e30363943
Kernel: Linux v5.15.146.1-microsoft-standard-WSL2
Distribution: ubuntu 22.04
Python: v3.10.12 (OK)
Container Engine: docker v24.0.5 (OK)
OpenLane Git Version: 9dbd8b5ea2bd891bed4dcc97df5c7439083f0368
python-venv: INSTALLED
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PDK Version Verification Status: OK
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Git Log (Last 3 Commits)

9dbd8b5 2024-01-11T15:26:56+02:00 Fix `-synth_explore` crash (#2085) - Kareem Farid -  (grafted, HEAD -> master, tag: 2024.01.12, origin/master, origin/HEAD)
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Git Remotes

origin  https://github.com/The-OpenROAD-Project/OpenLane.git (fetch)
origin  https://github.com/The-OpenROAD-Project/OpenLane.git (push)

Reproduction material

reproduction_material.zip

src rtl along with configuration tcl

Relevant log output

floorplan core utilization according to the configuration tcl
vijayank88 commented 3 months ago

set ::env(FP_CORE_UTIL) 0.7 update to set ::env(FP_CORE_UTIL) 40 and try. Core utilization in the range of 30-70 value normally and remaining space for routing.

Ashutosh-3107 commented 3 months ago

set ::env(FP_CORE_UTIL) 0.7 update to set ::env(FP_CORE_UTIL) 40 and try. Core utilization in the range of 30-70 value normally and remaining space for routing.

[INFO] Floorplanned on a die area of 0.0 0.0 1986.82 1997.54 (microns). Saving to /openlane/designs/Pipeline_top/runs/run1/reports/floorplan/3-initial_fp_die_area.rpt. [INFO] Floorplanned on a core area of 5.52 10.88 1981.22 1985.6 (microns). Saving to /openlane/designs/Pipeline_top/runs/run1/reports/floorplan/3-initial_fp_core_area.rpt.

It still utilizes most of the of the die area . I am doubting that if there is a gap in my understanding of how the command works

vijayank88 commented 3 months ago

Continue the flow and it will throw an error if more congestion. Check where it is stops now DPL/GRT

kareefardi commented 3 months ago

@Ashutosh-3107 Setting FP_CORE_UTIL affects both die area and core area. Core utilization is not the calculated relative to the die area. It is the area utilized by cells and macros of the deisgn inside the core (area). Die area is the core area with additional margins that are configured using BOTTOM_MARGIN_MULT, TOP_MARGIN_MULT, LEFT_MARGIN_MULT, and RIGHT_MARGIN_MULT