VEC file in combination with Dynamic Parameter

Dear JBury,

JBury said:

I encounter big issue when trying to run the transient simulation with dynamic parameter (Temperature) and using VEC file.Some stimululi are corrupted, very deteriorated, some events even missing. There is no issue at all when running pure transient simulation without dynamic parameter

There is a suggestion on the Cadence On-line support site for cases where a dynamic parameter change results in netlist topology change as a result of the PDK model behavior with temperature. The focus is not specifically on your observation, but it seems as if the experiment it proposes as a workaround might provide some added insight into the reason your results appear unusual relative to your expectations.

The article at URL:

https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1O0V000009ETrZUAW&pageName=ArticleContent

proposes running an Assembler or Explorer corner sweep at the discrete temperature breakpoints in your dynamic temperature setup GUI in lieu of the dynamic parameter simulation. Perhaps you have already tried this, and if so, I apologize for the suggestion! If not, you might consider it to provide insight on the failure mechanism.

Shawn

Hi Shawn,

thank you so much for the reply. Unfortunately it did not help. I really need to use VEC file in combination with dynamic parameter (temperature), I cannot separate temperature into several conditions, the temperature profile is complex, I need to use it like I described. The question is whether this approach is allowed.

Dear JBury,

Well, I struck out with that suggestion - sorry JBury!

This is not an area I have an expertise in, so I must apologize. Nevertheless, I did find a methodology that provides the same basic functionality as using the dynamic parameter feature in a transient analysis that may be of interest. Once again, please only try this if you think it worth your time as I've not tried it with a VEC file stimulus and don't want you to waste your time!!!

Basically, you create an external file that is included in the ADE setup as a model or stimulus file that Cadence calls a paramset. To change the temperature at specific simulation times, it might be something like:

Create a file (for example, myparamset.scs) and define the paramset as below:

mypset1 paramset {
time temp
0 25
100n 25
100.010n -40
500n -40
}

The instructions then indicate that the Transient GUI dynamic parameter radio button should be disabled, but the name of the paramset in the file you create ("myparamset.scs", as an example, is included in the additionalParams dialog box on the Transient Options Misc tab as shown from the note below.

The link to the note with the more complete set of instructions is URL:

URL to On-line support article on changing multiple parameters dynamically

Hopefully, the experts who monitor this forum can provide greater insight and more information than I to help you with greater certainty and their knowledge!

Shawn

Dear JBury,

Well, I struck out with that suggestion - sorry JBury!

This is not an area I have an expertise in, so I must apologize. Nevertheless, I did find a methodology that provides the same basic functionality as using the dynamic parameter feature in a transient analysis that may be of interest. Once again, please only try this if you think it worth your time as I've not tried it with a VEC file stimulus and don't want you to waste your time!!!

Basically, you create an external file that is included in the ADE setup as a model or stimulus file that Cadence calls a paramset. To change the temperature at specific simulation times, it might be something like:

Create a file (for example, myparamset.scs) and define the paramset as below:

mypset1 paramset {
time temp
0 25
100n 25
100.010n -40
500n -40
}

The instructions then indicate that the Transient GUI dynamic parameter radio button should be disabled, but the name of the paramset in the file you create ("myparamset.scs", as an example, is included in the additionalParams dialog box on the Transient Options Misc tab as shown from the note below.

The link to the note with the more complete set of instructions is URL:

URL to On-line support article on changing multiple parameters dynamically

Hopefully, the experts who monitor this forum can provide greater insight and more information than I to help you with greater certainty and their knowledge!

Shawn

Shawn,

I'm not sure how this latest suggestion would help, because it does exactly the same as using the dynamic parameter on the form (you're just using a netlist include to do the same as the UI would do for you).

To JBury, you need to provide more information. I can't see why this should be a problem - you've shown a graph with no context, so I've no idea what you're expecting..

That said, I was just about to ask for your vector file and tran analysis statement, but quickly tried it myself and see the problem you're seeing. It seems that this broke in SPECTRE18.1 ISR7 and is broken in current releases. Maybe if you really need it you can use a version before that, but I would advise contacting customer support and asking for a duplicate of the CCR I filed (CCR 2550437) to be created on your behalf so it can be tracked against a customer. It always helps to have clear customer impact in order to prioritise a fix.

Regards,

Andrew.

Hi Andrew,

I am very grateful you looked at it. When I used Spectre 18.1.0.314.isr5 the issue is really gone so I can continue. Anyway I will try to contact customer support as you proposed.

Thank you so much