Rise & fall time of a periodic signal

Dear side,

Yes. However, I have no idea what Cadence tool you are using to vary the capacitance nor what version of the Cadence tool  you are using. Hence, I am unable to provide any specific suggestions.

Shawn 

Dear side,

Yes. However, I have no idea what Cadence tool you are using to vary the capacitance nor what version of the Cadence tool  you are using. Hence, I am unable to provide any specific suggestions.

Shawn 

thanks for the reply , I am using IC 6.1.8 and sweeping the capacitance using the Tools -> Parametric sweep in ADE-L

Dear sI'm,

The Parametric tool, as you provide know, is quite old and both it and ADE-L are no longer supported by Cadence. You might seriously consider using a supported tool such as Explorer or Assembler. They are far more efficient and contain a lot more features.

Nevertheless, create a waveform expression using your output waveform and the risetime() Calculator (or ocean) function (see Figure 1) and add the expression to your ADE-L outputs and enable it as a plotted output. After your parametric analysis simulation completes, ADE-L will plot the risetime() expression against your Parametric swept variable.

Shawn

ok thanks for the reply, what is the suggested way to do this using ADE-XL ?

ADE XL has also reached end-of-sale (well, you have another 10 days) so is in the same status as ADE L. You should use Explorer or Assembler as Shawn said.

The flow is the same - you create an expression and then perform the sweep - it's just the mechanism for defining the sweep is different - the sweep is part of the design or global variables in the Data View assistant in Explorer or Assembler. You can do it with ADE XL too by sweeping global variables (you cannot sweep per-test design variables with ADE XL though). Since you're using IC6.1.8 there's no good reason to start using ADE XL now, you should use Assembler instead.

Andrew. 

thank you very much for the reply Andrew  & Shawn. I will try to see Assembler and Explorer.

In the meantime can you please let suggest how can I ensure whether the parametric sweep using ADE-L is going to converge. Asking this because out of the 5 linear steps the first 4 got completed soon and the parametric sweep is now stuck at the last step for last few hours (perhaps 4hrs or more).

The progress bar shows 80% but I am not sure if it is actually able to simulating the last step. I don't see any errors in the CIW as well.

I am not sure how much more time will it take so any suggestions will be helpful.

The first step would be to look at the spectre log file rather than just the summary of parametric analysis sweep. Simulation->Output Log would show that.

There's no hope of anyone here being able to diagnose what your problem is from so little information... we don't know what the circuit does, how it is (or even if it is) failing, and so on.

You might also want to consider turning on the "Enable Diagnostic Mode" on Setup->Environment so that the spectre log file gives more information as to what is going on and why progress is slow.

Regards,

Andrew.

thanks for the reply Andrew.

The circuit involves simulating an extracted view under different capacitance loads as per my previous snapshot. The first 4 sweeps went well and after looking hard on the ADE-L window I saw the status bar read "status ready" which was earlier something like "simulating 5e-12..."

The expressions inside ADE-L also seem to change in value to reflect that the final step has been simulated but the progress bar didn't seem to go beyond 80%.

Dear sidm,

sidm said:

The expressions inside ADE-L also seem to change in value to reflect that the final step has been simulated but the progress bar didn't seem to go beyond 80%.

Andrew is correct, the spectre.out file contains far more information regarding issues encountered in simulation than the "progress bar" you note and observe. That file is far more useful in debugging issues than the latter. Another item to consider is if you are submitting this job to an LSF farm or running it interactively.

I will note, however, that I used the Parametric Tool extensively in its day and found it would occasionally not complete the parametric run when running interactively. There are a multitude of reasons this occurred, but without the spectre.out file, I can't provide any specific guidance to you.

Shawn

thanks for the reply Shawn,

in the simulation log file i see "spectre completes with 0 errors, 61 warnings, and 27 notices."

But the progress bar of the parametric sweep is still stuck at 80% as per my previous snapshot.

I've not seen reports of this happening, but anyway you should be moving to using Explorer instead which has a different sweep mechanism,

Andrew