open-source-silicon.dev

in the xschem standard distribution i have a <https://xschem.sourceforge.io/stefan/xschem_man/tutorial_xschem_slides0812.html|8k x16bit ROM> that i have simulated with ngspice (14K mos transistors). The stimuli for ngspice is generated using utile, a stimuli processing language, another tool that comes with xschem:  the read cycles to run the simulation with ngspcice are coded like this:
~~~
unit n
voltage VCC
slope 0.2
format hspice

buswidth LDA 13 [ ]

buswidth LDSALDEL 2 [ ]
buswidth LDPRECHDEL 2 [ ]

param tck 16
param tah  2.5
param tas  2.5

alias cycle add en oe
  set LDEN en
  set LDOE oe
  set LDA add
  s tas
  set LDCP 1
  s tah
  set LDEN 0
  set LDA 0000
  s tck/2-tah
  set LDCP 0
  s tck/2-tas
endalias


beginfile stimuli_rom8k.cir

set VCC 0
set LDCP 0
set LDA 0000
set LDEN 0

s tck-0.1
set VCC 1
s 100
s tck-tas
;     add en oe
;=====================
cycle 0000 1 1
cycle 0011 1 1
cycle 0022 1 1
cycle 0033 1 1
cycle 0044 1 1
cycle 0055 1 1
cycle 0066 1 1
cycle 0107 1 1
cycle 0077 1 1
cycle 0088 1 1
cycle 0099 1 1
cycle 00aa 1 1
cycle 00bb 1 1
cycle 00cc 1 1
cycle 00dd 1 1
cycle 00ee 1 1
cycle 0000 0 0

endfile
~~~

This stimuli is then translated to spice PWL voltage sources:
...
...
VLDA[5] LDA[5] 0 PWL 0n 0 161.4n 0 161.6n VCC 166.4n VCC 166.6n 0 177.4n
+0 177.6n VCC 182.4n VCC 182.6n 0 225.4n 0 225.6n VCC 230.4n VCC 230.6n 0
+257.4n 0 257.6n VCC 262.4n VCC 262.6n 0 305.4n 0 305.6n VCC 310.4n VCC 310.6n
+0 321.4n 0 321.6n VCC 326.4n VCC 326.6n 0 369.4n 0 369.6n VCC 374.4n VCC
+374.6n 0
VLDA[6] LDA[6] 0 PWL 0n 0 193.4n 0 193.6n VCC 198.4n VCC 198.6n 0 209.4n
+0 209.6n VCC 214.4n VCC 214.6n 0 225.4n 0 225.6n VCC 230.4n VCC 230.6n 0
+257.4n 0 257.6n VCC 262.4n VCC 262.6n 0 337.4n 0 337.6n VCC 342.4n VCC 342.6n
+0 353.4n 0 353.6n VCC 358.4n VCC 358.6n 0 369.4n 0 369.6n VCC 374.4n VCC
+374.6n 0
...
...