When more than one simulations are ran without restarting ngspice, sometimes the later simulations fail to converge or return different results than when run alone.
Steps to repdroduce:
- Go to ngspice root directory and start ngspice.
- Type "source examples/TransmissionLines/cpl1_4_line.sp".
- Without restarting type: "source examples/TransmissionLines/cpl2_2_line.sp".
- Second simulation fails (doAnalyses: iteration limit reached), but it works correctly when run alone.
I have traced this bug to line 165 in frontend/spiceif.c. Uncommenting the "INPkillMods()" line fixes the bug.
This bug was introduced in commit 99b167b272027aabe4cbee573e4b7a87de63f69d "correct alter of mos geometries for binned models".