The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Simulators >> Circuit Simulators >> Performance analysis by spectre or any fast spice simulator
https://designers-guide.org/forum/YaBB.pl?num=1230805197

Message started by Rooney on Jan 1^st, 2009, 2:19am

Title: Performance analysis by spectre or any fast spice simulator
Post by Rooney on Jan 1^st, 2009, 2:19am

Hi,

I am running a top level simulation.
I would like to check the time taken by each sub-blocks using spectre simulator or any fast spice simulator

Basically, Spectre creates a flat level netlist and the log file has the information of the total simulation time. ( NOT the information about each block simulation time)

e.g. my top level consists of ADC, DAC, PLL, DLL. Now, if I run spectre or any fast spice simulation, it gives the total simulation time.
How is it possible to know the simulation time for each block in case of top level simulation with all the blocks active.

How to enable that feature in ADE or whatever way or which analog tool supports that for transistor level simulation.

Back to top

Title: Re: Performance analysis by spectre or any fast spice simulator
Post by Andrew Beckett on Jan 2^nd, 2009, 7:37am

It's hard to see how this could be done, at least in a simulator that doesn't partition the design. Given that you have to solve a whole bunch of simultaneous equations, and converge on a solution - the simulation time is dependent on the whole circuit. I guess you could potentially keep track of when all the equations for a particular block have converged, and when you're tracking time, ignor eany time after that.

This would all assume that there's no interaction between the blocks - it may be that as other parts of the circuit converge on a solution, they start affecting other blocks which were previously converged, for example.

Anyway, suffice to say, there isn't a way of doing this with spectre or other simulators that I know of (perhaps it is possible with some - but I've not come across such a feature; I'm not convinced it would be terribly useful).

Regards,

Andrew (first post after a long absence!)

Title: Re: Performance analysis by spectre or any fast spice simulator
Post by Rooney on Jan 5^th, 2009, 6:02pm

Hi,

This can be useful for the analog modeling. If we want to chose the blocks that consume large simulation time, we can go for that block for modeling

Title: Re: Performance analysis by spectre or any fast spice simulator
Post by Andrew Beckett on Jan 6^th, 2009, 1:42am

I would assume you would know that information from simulating the blocks individually as you design them - but I get your point.

Regards,

Andrew.