https://open-source-silicon.dev logo
Join Slack
Powered by
I'm currently testing the OSU FreePDK 45nm with th...
# openlane
h
I'm currently testing the OSU FreePDK 45nm with the simple test design 'spm'. I'm encountering large no. of errors during the SPICE export and DRC check steps of the flow inspite of getting 0 violations after routing. Any idea what could be the cause of the error? I have attached the config.tcl, magic_spice.log and magic_drc.log for your reference. Kindly look into it.
magic.drcmagic_ext2spice.feedback.txtmagic.drc.logmagic_spice.logconfig.tcl
@Amr Gouhar @Ahmed Ghazy any idea how to resolve this?
a
Could you share more information on how the 
mag
files were generated?
Have you used open_pdks to do so?
h
@Ahmed Ghazy As of now, I followed the PDK directory structure in the Openlane readme file and I have the .lib, .lef and .techLEF files under the libs.ref directory and the files needed by openlane (config.tcl, common_pdn.tcl, no_synth.tcl, tracks.info), magic (.magicrc, .tech) under the libs.tech directory of the PDK root. Do I necessarily have to use open_pdks to generate the .mag and .maglef files in order to run the SPICE export and DRC check?
a
Yes, you need .mag files if you'd like to be able to do post-routing physical verification using magic and netgen.
h
@Ahmed Ghazy Thanks!! I'll try to generate the .mag files using open_pdks. I'll ping you in case I face some challenge in the process.
a
If you set up a directory similar to 
sky130
under the open_pdks repo, I can give you guidance with the 
<http://Makefile.in|Makefile.in>
and autoconf.
h
Sure @Ahmed Ghazy. I'll do the same and let you know once I'm done with the setup.
@Ahmed Ghazy I have tried modifying the sky130 Makefile to suit the gscl45nm. However, the .mag files aren't generated after executing 'make'. I kindly need your help in this regard. I have attached both the modified makefile and the pdk_install.log for your reference.
gscl45nm_install.loggscl45nm_makefile
https://github.com/harikumar27399/OSU-FreePDK45-gscl45nm-setup-for-Openlane-flow-Work-in-Progress- I have set up the above git repo which includes files needed for open_pdks install similar to the sky130 directory under the open_pdks repo. Kindly look into it @Ahmed Ghazy
@Ahmed Ghazy I fixed some minor issues in the Makefile. Now the libs.tech directory seems to be in place. However, all the sub-directories (mag, maglef, gds, lib, lef, techlef) under the libs.ref directory are empty. It looks like the open_pdks installer somehow fails to read the PDK files. I have attached the updated modified Makefile and install log. Kindly have a look at it.
gscl45nm_install.loggscl45nm_makefile
@Ahmed Ghazy I have fixed all the errors in the open_pdks Makefile and successfully generated the .mag files for the ODU 45nm PDK. However, the errors in the 
run_magic_spice _export
and 
run_magic_drc
steps persist. Any idea what could be the cause of this?
@Ahmed Ghazy I kindly request you to have a look at this issue. Should I specifically add the path to .mag files in any of the TCL scripts so that they get detected?
a
@Harikumar S: Sorry about the delay. I am suspecting that you do not have a .magicrc or magic tech file in place under 
libs.tech
?
h
@Ahmed Ghazy I do have the .magicrc and magic tech file up and running under the libs.tech folder. I have also resolved the errors during SPICE extraction by fixing the issue in common_pdn.tcl. Now only the DRC errors are remaining. Tim Edwards has asked me to manually cross verify the DRC errors reported with the layout to determine whether they are actually right. Do you suggest any other changes in the Openlane flow configuration file to fix the issue in an automated way?
a
I haven't worked with OSU 45nm myself, so I don't know how good the magic-specific files are, and whether the spacing errors you're getting are real. I would spot-check one or two errors manually as Tim suggested as a start to debug this.
87 Views
Open in Slack
PreviousNext
Powered by