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Simulators >> Circuit Simulators >> Long simulations time on Hspice
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Message started by shuting84 on Apr 16^th, 2006, 2:14pm

Title: Long simulations time on Hspice
Post by shuting84 on Apr 16^th, 2006, 2:14pm

Dear all,

I am trying to run simulations for all the possible input transition vectors for a 4 bit adder (then subsequently a 4bit multiplier) that would result in a change at the output. I wish to measure the Current during the transition and the transition delay.

Now the problem is: there seems to be too many transition vectors and the simulation time seems to be too long. Hspice seems to not like this and gives lots of problems. Is there any means which I can continue doing my simulations without having to break up my simulations?

Because if I really have to break up my simulations, I will probably need up to 100 of separate simulations.

Title: Re: Long simulations time on Hspice
Post by imtired on Jun 20^th, 2006, 12:54pm

What type of problems is HSPICE giving you?

In my experience, the problem I encountered with long transient simulation times is the trucation of fine step sizes, due to limitations in the precision of time values stored by HSPICE. I don't know whether or not they have addressed this issue yet, but the last time I checked with HSPICE support, they told me to break up the simulations by saving the end state and using it to initialize the next simulation, successively over the entire simulation range, and each simulation file *.tr0 would need to be renamed to *.tr1, *.tr2, *.tr3, etc... to prevent over-writing the previous simulation.