Simulators exit suddenly

[oshouman]

Dear all,

I am having a problem with simulation. The simulator (ModelSim) simply exits or crashes suddenly when I start running the simulation (i.e. after typing run 100, for example). In other words, the simulation window appears with the waves shown but when I start to run, it exits without any error or notification message. I downloaded Xilinx Webpack and tried to simulate my design on it, but I got almost the same (the simulation window closes but the software remains open).

I hope somebody could help. This problem is hindering my progress in the project I am working on.

Thank you all in advance

 

[scottcarl]

Ahhhh Modelsim! This tool has had this problem for at least 9 years and they still haven't decided to fix it. It's one of the reasons I avoid it whenever I can and use something else. You'd have to posta snippet of rtl or testbench code to truely see what the issue is. It sounds like it's crashing just after a 'reset' deactivates but it's hard to tell. You might try stepping very slowly through your simulation (steps, not a full run) and determine where in your simulation or code the crash occurs. It will usually crash when in some obsucure library file so you'll have to see what 'known (user generated)' file it steps into before heading down into the unknown. This will take many iterations to figure out.

Good luck,
Scott