Making a move from another well known simulator!

Hi,
I am super excited about some of the features that QSPICE promises. In particular the embedded C subckts. Having said this I am trying to understand how I can move over from another well loved simulation package :wink: for which I have already developed many IC behavioral models.

The first time I have spun up QSPICE I already see some functional behaviour of the waveform viewer that is not quite what I expected or what I was accustomed to. This is the ability to view simulation output in real time using ā€˜marching waveformsā€™. Is this something that is already supported, if so I can not find a way to control this?

Secondly, I am curious to know if QSPICE supports the ā€œ.MACHINEā€, primitive of an arbitrary state machine. I have attempted to use one of my existing models which uses the state machine structure, but it does not seem to work. I have used arbitrary state machines extensively to build mixed signal models that include things like counters and other such ā€˜digitalā€™ elements. I am excited to embrace the concept of embedding ā€˜Cā€™ directly into the spice source to overcome some of the limitations of these state machine / behavioral modelling techniques, but I was hoping for a smoother path from my current models and workflow.

Furthermore debugging this process is also hampered by the fact that I can not seem to find a way to record subckt nodal voltages and currents. I also do not see these available as a manual entry from within the ā€˜add plotā€™ dialogue of the waveform viewer. Therefore I can only assume that the simulation does not record subckt details by default.

Any further suggestions about how, if possible, I can gain some more fine grained control of the program.
This would be very helpful.

All the best
Aidan

Welcome to the forum, Aidan.

What well-known simulator are you coming from?

ā€“robert

LTspice, of course.
It is not however an unreasonable question, as I have wondered if state machine primitives are available in other simulators?

Hi Robert,
After a little further investigation, it seems that the issue with marching waveforms is something to do with the virtualisation I am using. I have QSPICE operating under KVM on an Ubuntu host. It seems that something about the CPU topology configuration of the guest OS causes the windowing inside the guest OS to screw up. I reserved a single core of my CPU for exclusive use of the host and when I did this I can now see marching waveforms in the waveform viewer of QSPICE.
Aidan

Hi, Aidan. Glad you solved it.

ā€“robert