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#openlane
Title
# openlane
n

Nate Young

11/30/2020, 10:11 PM
We have a custom cell, about the size of a strength-2 inverter, and after a few modifications to fix DRC errors that appear in the final GDS the openroad antenna checker now crashes.
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[ERROR]: during executing: "openroad -exit /openLANE_flow/openlane/scripts/openroad/or_antenna_check.tcl |& tee >&@stdout /openLANE_flow/ix_yukio/asic_config/usb/runs/30-11_22-00/logs/routing/or_antenna.log"
[ERROR]: Exit code: 1
[ERROR]: Last 10 lines:
child killed: segmentation violation

[ERROR]: Please check openroad  log file
[ERROR]: Dumping to /openLANE_flow/ix_yukio/asic_config/usb/runs/30-11_22-00/error.log
a

Amr Gouhar

11/30/2020, 10:24 PM
Probably, your cell doesn't have the appropriate ANTENNA information in the LEF file. i.e.
ANTENNADIFFAREA
. (This is more of a wild guess).
n

Nate Young

11/30/2020, 10:28 PM
That's a good guess, but I checked and it does have
ANTENNADIFFAREA
and
ANTENNAGATEAREA
.
a

Amr Gouhar

11/30/2020, 10:34 PM
@Nate Young: Then to get working you can add this to your config.tcl
set ::env(USE_ARC_ANTENNA_CHECK) 0
. This will allow you to use magic's antenna checker instead. It takes more time but it's as good. However, you probably should open an issue about that.
❤️ 1
👍 1
n

Nate Young

11/30/2020, 10:35 PM
Thanks, I'll try that
a

aryap

11/30/2020, 10:38 PM
🙌
n

Nate Young

11/30/2020, 10:39 PM
It works!
a

Aled Cuda

11/30/2020, 10:41 PM
I think it may have been related to https://github.com/efabless/openlane/issues/25 but I can't figure out how it was fixed
a

Amr Gouhar

11/30/2020, 11:08 PM
@Aled Cuda: That was a different case, the LEF files for the diodes of sky130_fd_sc_hs and sky130_fd_sc_ms were completely wrong at that time. However, after a couple of iterations with Tim Ansell we managed to get them fixed and that issue was resolved. Also, we were not running detailed placement after CTS, relying that it will be done after diode insertion however for hs and ms since the diodes were not inserted this was causing a lot of trouble and segfaults. Still, this issue was fixed as well.
a

Aled Cuda

11/30/2020, 11:20 PM
Ah ok then