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Simulators >> AMS Simulators >> Bug in Spectre Waveform Calculator Tool ???
https://designers-guide.org/forum/YaBB.pl?num=1141133530

Message started by vivkr on Feb 28^th, 2006, 5:32am

Title: Bug in Spectre Waveform Calculator Tool ???
Post by vivkr on Feb 28^th, 2006, 5:32am

Hi,

I have noticed a problem with the latest Cadence version 5.10.41. The waveform calculator tool
now performs an instantaneous evaluation of the buffer, which makes it difficult to define
complicated expressions based on a signal.

I will give an example, using symbolic syntax instead of the actual one used.

Suppose, you are trying to take a waveform, do an FFT on it, take the dB20 value, and plot it
The steps might be:

1. Select transient signal.
2. FFT( define start, stop, number of points, window)
3. dB20
4. plot

This used to work well before. Now, when I do step 1 and select a
transient signal, and attempt to go to step 2, the calculator already has
evaluated its buffer, and gives me something like:

dr18233... in the buffer or

nil

depending on whether there is any data corresponding to the signal entered.

This is quite unhelpful as one is unable to use the calculator properly, especially if one
intends to use it to define some useful outputs.

I am getting along so far by just typing out the entire complicated expression at once, and praying that
it is indeed what I wanted. But if you try f1( f2( f3( f4( x) ) ) ), then you are likely to miss something.

Does anyone know why this is happening? Is there some way out? I use the AWD waveform display
instead of the WaveScan.

Regards
Vivek

Title: Re: Bug in Spectre Waveform Calculator Tool ???
Post by Andrew Beckett on Feb 28^th, 2006, 7:45am

You haven't turned on the "Evaluate buffer" checkbox by accident have you? I've not seen this happen before unless that's set, and it has behaved this way for ever...

Andrew.

Title: Re: Bug in Spectre Waveform Calculator Tool ???
Post by vivkr on Mar 8^th, 2006, 3:50am

Hi Andrew,

Thanks for the tip. I will keep this in mind. However, I cannot tell if this might have been the error as I have
closed that Cadence session long ago.

I am aware that setting "evaluate buffer" to ON causes the contents to be automatically evaluated,
and so I never set this option.

However, it might be that this was the case as I did not see the problem once I restarted Cadence.

Regards
Vivek