Hey everyone, I have been having an issue with par...
# magicd
Derek Hines-Mohrman
04/08/2022, 5:07 PMHey everyone, I have been having an issue with parasitic extraction. I am seeing a lot of "nan" and "-inf" capacitance values.
When looking at the extraction log, I see some warnings "Missing substrate connection of device at ...". I am pretty sure all the substrates are connected correctly in this design because DRC checks for that (in "complete" mode).
Attached is a snipped of the extracted spice model and the extraction log.
Also attached is the design (top level is "SSTL.mag") and the extraction script.
Derek Hines-Mohrman
04/09/2022, 7:18 PMI figured out the "missing substrate connection" warning isn't the issue. The warning appears to happen when a n-fet does not have an explicit pwell layer under it. As far as I can tell, this isn't related to any other issue...
t
Tim Edwards
04/10/2022, 2:16 AMWhat version of magic? Also, what version of open_pdks?
Tim Edwards
04/10/2022, 2:18 AMI can't tell exactly from the screenshot, but are you running "extresist" on a hierarchical layout? Because that's known to have many issues.
d
Derek Hines-Mohrman
04/10/2022, 2:38 AMMagic version 8.3.277,
open_pdks version 1.0.303
The cell should have been flatted before extraction...
I meant to add the extraction script to that tar... but looks like I forgot. Here it is.
2 Views