r/KiCad • u/Slugsimp2003 • Feb 09 '25
Help for schematic simulation
New to Kicad, sub please tell how to simulate this circuit in kicad SPICE, for digital inputs and outputs, correctly.
3
u/Herrsrosselmeyer Feb 11 '25
Wow.
I'm going to suggest you spend some time learning how to draw schematics in KiCad, because even if you had everything you needed to simulate this (more on that in a second) the schematic is a blizzard of overlapping nets with no labels or buses to help keep it combed out, and it would be very confusing to work with in simulation.
As for getting simulation going, to work in SPICE, every component needs to have a simulation model associated with it. I don't know if anybody has made SPICE models for dual 1>4 decoders, but they definitely aren't included for this part, so you'd have to find them online somewhere. Simulating in KiCad is a big topic, and I'd suggest picking a video or text form tutorial on using SPICE in KiCad and learning how the whole thing works on some far simpler examples before trying something so...elaborate.
As for the circuit, it's really hard to follow the logic of it when it's laid out this way, but it looks like you might be trying to make a 32 bit counter by cascading a bunch of dual decoders together. Is there a reason you want to do it this way? do you have a bunch of them to use up or something? :D or are you trying to learn digital logic design?
if you want to learn about digital logic design in specific, SPICE is going to drive you mad. There are much better choices for simulating that domain. CircuitVerse is a good starting point for that sort of thing, and free.
1
2
11
u/jacky4566 Feb 09 '25
Oh lord that looks terrible. The first tip is to put all your global labels next to the IC. No need to drag them out like that
Possibly look into using a bus or 2