What makes the UltraSim simulator better than others?

[tonyo_guy]

USIM

Can anyone tell me what makes the UltraSim simulator better than any "normal" spice simulator?
If it's only accuracy....
Is it Cadence designed simulator,or bought with a small company by Cadence?

 

[HCM_bucat]

Re: USIM

UltraSim can be classified as a Fast Spice simulator. It is a kind of sumulator that speed up the simulationand handle bigger design with the price of losing accuracy. In this genre are:Hsim, Star-SimXT, Time-Mill, PathMill, Nanosim, aand other tools from Mentor.
UltraSim first developed by Celestry which was later acquire by Cadence.
According to Dataquest, Marketshare this tool is not even a competitor of the above mention tools.

 

[tonyo_guy]

Re: USIM

I see...
USIM is faster,with lower accuracy.
But can we achieve the same result if we degrade the accuracy of a normal spice simulator?
I mean if this tool worths or not.

 

[tochaHCM]

Re: USIM

Sure, it worths. But you ahve other choice. You must find the rationale behind it using. You have no other tools, you don't want to learn other tools, you customers want to to you that tools , you get it free from Cadence etc...

 

[simonkuo]

Re: USIM

I usually use the USIM to check the hole chip behavior and
check small block circuit in hspice.
Because the faster simulation time the lower accuracy.
Usually these fast-spice tools use the spice-table and throw away many
circuit parameter, so maybe its result seems better, but lower accuracy.