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Design >> Mixed-Signal Design >> freq_meter component in ahdlLib
https://designers-guide.org/forum/YaBB.pl?num=1165571338

Message started by adesign on Dec 8^th, 2006, 1:48am

Title: freq_meter component in ahdlLib
Post by adesign on Dec 8^th, 2006, 1:48am

Dear all,

I'm using freq_meter component from ahdlLib to calculate instantaneous frequency of an oscillator. While doing Spectre simulation, I'm getting the error as

==========================================================
Error found by spectre at time = 20.6089 ns during transient analysis `tran'.
Signal FF(FREQ_OUT) = 2.18688 GHz exceeds the blowup limit for the quantity
`FF' which is (1 GHz). It is likely that the circuit is unstable. If
you really want signals this large, set the `blowup' parameter of this
quantity to a larger value.
==========================================================

Please let me know how to resolve this issue.

Title: Re: freq_meter component in ahdlLib
Post by ACWWong on Dec 8^th, 2006, 2:38am

you need to increase the blowup limit for the nature Frequency.

See the relevant previous post.
http://www.designers-guide.org/Forum/YaBB.pl?num=1160447769/1#1

Title: Re: freq_meter component in ahdlLib
Post by Ken Kundert on Dec 8^th, 2006, 2:33pm

Do you really need the frequency to be a signal? Is it driving something else in the circuit? If not, modify the model to make the frequency a local variable rather than a signal. Then plot it using the waveform browser.

-Ken

Title: Re: freq_meter component in ahdlLib
Post by Ken Kundert on Dec 8^th, 2006, 2:51pm

All,
Please remember that this forum is a general resource for everyone. As such, you should try to ask your questions in a way that everyone benefits from the answer. In that spirit, if you have a question or comment about a model, you should include the model here or give a pointer to where it is publicly available. If you ask about proprietary models that many visitors do not have access to, then you limit the number of people that can answer your question and the number that benefit from a response. If you really need to ask a question about a proprietary model, try to develop an abstract or alternate version that exhibits the same behavior and use that to ask your question.

Thanks,
-Ken