preparation for verifying large blocks

Dear ichiro,

ichiro said:

What should I be careful about convergence?

There typically are only a few issues that lead non-covergence - such as multiple valid startup states with out forcing nodes, uninitialized circuits nodes of subcircuits with  memory, and circuit schematic topology errors. I'm not sure if any of these might apply in your case. If the DC operating point in a spectre analysis does not converge, the  spectre.out log file will include a number of suggestions to improve the likelihood of DC convergence, Hence, study each of these if you encounter DC convergence issues.

The subject is widely documented in the Cadence On-line support site. If you do not have an account, I suggest you create an account. A few follow and I hope these provide you some guidance ichcro.

Shawn

The use of .ic and .nodeset commands are different - an outline of their differences and uses may be found at the On-line support URL:

support.cadence.com/.../ArticleAttachmentPortal

You might also consider the use of the +dcopt environmental option described at URL:

support.cadence.com/.../ArticleAttachmentPortal

or the +diagnose option detailed at URL:

support.cadence.com/.../ArticleAttachmentPortal

and 

support.cadence.com/.../ArticleAttachmentPortal

support.cadence.com/.../ArticleAttachmentPortal

Hi ShawnLogan,

Thanks for your suggestions to help my knowledge for simulation convergence. 

And if you have another keyword for convergence, plz tell me it, thanks.

Ichiro

Dear ichiro,

ichiro said:

help my knowledge for simulation convergence. 

I hope they are helpful to you!

ichiro said:

And if you have another keyword for convergence, plz tell me it, thanks.

If you are looking for a search term, I would suggest looking at the bottom of the URL pages I provided. Cadence On-line support pages have a section at the bottom of each with links to similar topics. I've illustrated an example as Figure 1.

Shawn

Figure 1

Hi Shawn,

I'd like to know usage of +dcopt.

The manual says "dcopt is invoked via the +dcopt command-line option"

Where is the command-line? Is that a CIW or "dc-->options...-->additional parameter" or another one?

Thanks,

Ichiro

Ichiro,

This would be done via Setup->Environment and then typing in "+dcopt" on the User Command-Line Options field.

Andrew.

Dear Andrew,

Thank you for answering in my absence! 

I hope this answers your question Ichiro.

Shawn

Hi Andrew and Shawn,

Thanks for your answer!

And I have a additional question now, which is "how can I call the +dpopt in ocean ?".

Thanks,

Ichiro

Dear ichiro,

ichiro said:

And I have a additional question now, which is "how can I call the +dpopt in ocean ?".

Did you happen to study the ocean reference manual? It details the envOpt() function which can be used to set user environmental options. The URL on the On-line support site is:

OCEAN Reference -- Using OCEAN - Selectively Creating Scripts

with the specific settings shown at the On-line support document

Virtuoso Analog Design Environment L User Guide -- Environment Variables - ADE Simulation Environment

As an alternative, you can generate an ocean script directly from a test in Explorer. If you have included +dcopt as Andrew suggested in its user command line options, as shown in Figure 1, when you generate an ocean script using the menu option shown in Figure 2, the relevant syntax for the command will be included in the resulting ocean script. A abbreviated version from the ocean script I just created is shown below.

envOption(
'userCmdLineOption "+lorder MMSIM:PRODUCT +dcopt +disk_check=100e9"
)

I hope this helps.

Shawn

PS There is a wealth of information available in the On-line support site and I think alll the questions you asked have answers in the site. If you do not have an account, I highly suggest you create one.

Figure 1

Figure 2