Running AC and DC simulation in the same time

To do what you are asking for, you need to do a sweep around the AC analysis. An AC analysis, like DC and transient can sweep one variable - for AC that is typically frequency, but it can be something else (e.g. a parameter or temperature) and then the AC is computed at a single frequency. If the DC operating point is affected by whatever you are sweeping, it is recomputed before computing the AC for the single frequency you specify. DC is similar - you can sweep a parameter or temperature.

If you need to do a frequency sweep and sweep something else, you need to do a nested sweep. Spectre itself supports a native sweep analysis, but ADE doesn't generally take advantage of this (there are a few case where ADE does use spectre's sweep analysis, but this is not one of them).

However, if you run ADE Explorer to set up the surrounding sweep, then spectre would (normally) run with similar efficiency to having a native sweep. That's because it groups the runs and ADE tells spectre to run each set of analyses without quitting the simulator - so you don't need to generate a new netlist, re-start the simulator, regain the license, parse the netlist and so on - spectre will change the parameter value in memory.

ADE L can do this too (to some extent) with the parametric analysis tool.

It's possible that your setup is defeating the performance improvement to make parametric sweeps faster - to know that, I'd need to know which ADE flavour you're using and which version of the IC tools you're using. Then I can ask you some relevant questions. Fundamentally though, you need to do a parametric sweep of some sort around the AC analysis - so that will inevitably be slower because it has to repeat the AC sweep for each outer variable sweep point.

Regards,

Andrew.

Hello Andrew,

Thank you for your reply

I am using ADE L,   Spectre Simulator version 11.1.0.509      2012 

and Cadence Virtuoso IC6.1.5-6b bit

We don't have ADE Explorer in our platform

Thank you Andrew again

Regards 

OK, check what:

envGetVal("spectre.envOpts" "controlMode")

returns. If that returns "interactive", then doing the parametric sweep should be quick (assuming you're not running in distributed mode in ADE L). If it's set to "batch" then do:

envSetVal("spectre.envOpts" "controlMode" 'string "interactive")

and restart ADE L and try the parametric analysis tool again.

ADE Explorer was introduced in IC617. You're using very old and unsupported versions at the moment (7 years or so old).

Regards,

Andrew.

Dear Andrew, 

That was very helpful, the Parametric analyses is now working faster with your last suggested setting. 

I have a question related to this solution, is the simulation accuracy reduced when we make it faster?

Thanks

NorNand said:

I have a question related to this solution, is the simulation accuracy reduced when we make it faster?

No, it's not.

Andrew.

Thank you Andrew for your kind help

Thank you Andrew for your kind help