We are trying to integrate digital macros from openlane with our analog layout, and our goal is to try parasitic extraction and simulation with ngspice to see how the digital and analog are interfacing. I am running into port problems on the extracted spice file where decap cells are being reduced to two ports (vccd1 and vssd1), but I thought I'd get four ports (I am aware of the caravel_user_project_analog's suggestion to use

ext2spice short resistor

during extraction). The ext files do have four ports:

timestamp 1644511149
version 8.3
tech sky130A
style ngspice()
scale 1000 1 500000
resistclasses 4400000 2200000 <tel:9500003050000|950000 3050000> 120000 197000 114000 191000 120000 197000 114000 191000 48200 <tel:3198002000000|319800 2000000> 48200 48200 12800 125 125 47 47 29 5
parameters sky130_fd_pr__nfet_01v8 l=l w=w a1=as p1=ps a2=ad p2=pd
parameters sky130_fd_pr__pfet_01v8_hvt l=l w=w a1=as p1=ps a2=ad p2=pd
port "VPWR" 4 0 496 368 592 m1
port "VPWR" 4 29 527 63 561 m1
port "VGND" 1 0 -48 368 48 m1
port "VGND" 1 29 -17 63 17 m1
port "VPB" 3 29 527 63 561 nw
port "VNB" 2 29 -17 63 17 pw
node "decap_4" 0 0 0 0 comment 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
node "VPWR" 0 0 29 527 m1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
node "VGND" 0 0 29 -17 m1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
node "VPB" 0 0 29 527 nw 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
substrate "VNB" 0 0 29 -17 pw 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
device msubckt sky130_fd_pr__nfet_01v8 79 47 80 48 l=210 w=110 "VNB" "VPWR" 420 0 "VGND" 220 0 "VGND" 0 0
device msubckt sky130_fd_pr__pfet_01v8_hvt 79 323 80 324 l=210 w=174 "VPB" "VGND" 420 0 "VPWR" 348 0 "VPWR" 0 0

But the

ext2spice

output drops them on the spice file (I see two port instances like

XFILLER_39_233 vssd1 vccd1 sky130_fd_sc_hd__decap_4

)...is there another command to be used besides

ext2spice

? @Tim Edwards

It should not be possible to lose declared ports. Are you sure that's the magic-generated netlist??

Sorry my bad the command works ok