problems when plotting waveforms generated by drCreateWavefo

[yfeng0036]

Hi everybody,
I am using ocean and skill to read in a file with an S21 loss curve and overlaying that curve on top of my equalizer's AC simulation results.

In Cadence 6.1.3 (where the project was initially set up), I could run the following code:

spwave = drCreateEmptyWaveform()
xvec = drCreateVec( 'double lFreq )
yvec = drCreateVec( 'double lDb )
drPutWaveformXVec( spwave xvec )
drPutWaveformYVec( spwave yvec )
plot(clip(spwave 50M 40G) clip(db20(getData("vout" ?result 'ac)) 50M 40G))

where lFreq and lDb are the list formats of the s-parameter file and "spwave" is the waveform object of the S21 file. the plot command will clip the S21 waveform object and the /vout node from the AC simuation (from 10khz -> 100ghz) and plot them both on the same subwindow.
I can also select both waveform objects in the calculator and evaluate expressions.

However, in the newer Cadence 6.1.5 environment we have been updated to, the plot command refuses to draw the db20 of the /vout node on the same subwindow as the S21 wave. Also, clipping the S21 waveform does not properly clip from 50Mhz to 40Ghz, instead it produces a flat line.

I couldn't find anything indicating this in the documentation from reading through the SKILL/ocean commands i have used. Is there a new method for what I have done in 6.1.5?

Thanks,
Yu Feng

 

[yfeng0036]

I have noticed that in the "known bugs" with the 6.1.5, they have a problem with clip() not working as intended for "reverse DC sweeps" and they can't plot multiple graphs with different x-axis types (log vs linear)... and neither of these problems have a current solution given in the help files.

Is my problem related to this?
Thanks,
Yu Feng

On Wednesday, June 26, 2013 10:02:37 PM UTC-7, yfeng0036 wrote:

Hi everybody,

I am using ocean and skill to read in a file with an S21 loss curve and overlaying that curve on top of my equalizer's AC simulation results.



In Cadence 6.1.3 (where the project was initially set up), I could run the following code:



spwave = drCreateEmptyWaveform()

xvec = drCreateVec( 'double lFreq )

yvec = drCreateVec( 'double lDb )

drPutWaveformXVec( spwave xvec )

drPutWaveformYVec( spwave yvec )

plot(clip(spwave 50M 40G) clip(db20(getData("vout" ?result 'ac)) 50M 40G))



where lFreq and lDb are the list formats of the s-parameter file and "spwave" is the waveform object of the S21 file. the plot command will clip the S21 waveform object and the /vout node from the AC simuation (from 10khz -> 100ghz) and plot them both on the same subwindow.

I can also select both waveform objects in the calculator and evaluate expressions.



However, in the newer Cadence 6.1.5 environment we have been updated to, the plot command refuses to draw the db20 of the /vout node on the same subwindow as the S21 wave. Also, clipping the S21 waveform does not properly clip from 50Mhz to 40Ghz, instead it produces a flat line.



I couldn't find anything indicating this in the documentation from reading through the SKILL/ocean commands i have used. Is there a new method for what I have done in 6.1.5?



Thanks,

Yu Feng

 

[Andrew Beckett]

On 06/28/13 00:12, yfeng0036 wrote:

I have noticed that in the "known bugs" with the 6.1.5, they have a
problem with clip() not working as intended for "reverse DC sweeps" and

they can't plot multiple graphs with different x-axis types (log vs
linear)... and neither of these problems have a current solution given
in the help files.

Is my problem related to this? Thanks, Yu Feng

I think the clip issue was fixed - in a hotfix - but I'm not sure this
is relevant. It's really hard to tell from the segment you've given.

BTW, ViVA can directly read touchstone (or spectre) format S-parameter
files, so maybe your code isn't needed anyway (this was introduced in
IC614, and improved in IC615).

Regards,

Andrew.