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Guild: wafer.space Community
Channel: Information / questions / Pin Placement
After: 10/31/2025 23:59
Before: 12/01/2025 00:00
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[11/29/2025 20:04] buck_042
Hi all. I’m using the template project to PnR some small digital modules and plan to integrate them into a larger analog block. I’m not using the template configs, just the Librelane environment.
I have a question: how can I more precisely customize pin locations? Is there any script or config that lets me specify the absolute position of each pin on the floorplan? With pin_order.cfg I can only spread pins evenly along one side.
Any help will be appreciated.


[11/29/2025 20:48] 246tnt
The easiest is to the the "DEF template" feature. See FP_DEF_TEMPLATE.


[11/29/2025 20:48] 246tnt
Then you can write a DEF that define exact positions of the pins you want.


[11/29/2025 23:05] buck_042
Thank you! Are there any DEF template files that I can use as a reference?


[11/30/2025 08:37] bailey8889
@Buck the caravel's user_project_wrapper uses one. https://github.com/chipfoundry/caravel_user_project/blob/main/openlane/user_project_wrapper/fixed_dont_change/user_project_wrapper_gf180mcu.def

{Embed}
https://github.com/chipfoundry/caravel_user_project/blob/main/openlane/user_project_wrapper/fixed_dont_change/user_project_wrapper_gf180mcu.def
caravel_user_project/openlane/user_project_wrapper/fixed_dont_chang...
Contribute to chipfoundry/caravel_user_project development by creating an account on GitHub.
2025-11_media/caravel_user_project-AE990


[11/30/2025 08:41] 246tnt
https://github.com/TinyTapeout/tt-support-tools/blob/main/tech/gf180mcuD/def/tt_block_1x1_pgvdd.def

{Embed}
https://github.com/TinyTapeout/tt-support-tools/blob/main/tech/gf180mcuD/def/tt_block_1x1_pgvdd.def
tt-support-tools/tech/gf180mcuD/def/tt_block_1x1_pgvdd.def at main ...
Tiny Tapeout project build tools + chip integration scripts - TinyTapeout/tt-support-tools
2025-11_media/tt-support-tools-64586


[11/30/2025 08:42] 246tnt
Tiny Tapeout  above also use some and they're pretty minimal.


[11/30/2025 17:24] buck_042
Thank for everyone's help!


[11/30/2025 17:29] egorxe
If you have an abstract LEF (for example after LibreLane run with pin placement you would like to fix) you could easily make a template DEF from it with magic, [like this](https://github.com/egorxe/gf180mcu-sram-wrappers/blob/main/utils/magic_def.tcl).

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