Generate X versus Y plot with OCEAN or Skill (example Eyediagram)

Hy,

Does somebody know how to setup a X versus Y Plot in OCEAN or Skill?

I want to generate a Eye diagram automatically
For that I need to plot on the X-Axis a Sawtooth signal instead of the time
axis

I searched in the online help documents, but I found nothing.


Thanks for any help


Best regards

Norman

 

In the Waveform Window, setup the X-axis
to another variable.
I don't remember the exact menu commands
right now but you shouldn't have trouble
doing this.

Using the waveform function you can certainly
do this in skill (awe* functions i guess).

stéphane

 

Hi Norman,

The first thing to say is that there is an eyeDiagram function in IC50, based on
some code I wrote a while back, which may do what you want.

Secondly, to do an X versus Y in SKILL, you can use:

/*******************************************************************
* *
* (abChangeXAxis yVar xVar) *
* *
* Return a new waveform object with the x axis set to the y values *
* of the second argument. *
* *
*******************************************************************/

(procedure (abChangeXAxis yVar xVar)
(let (newWave)
(setq newWave (drCreateEmptyWaveform))
(drPutWaveformXVec newWave (drGetWaveformYVec xVar))
(if (eq (drGetWaveformXVec yVar) (drGetWaveformXVec xVar))
/* if the x axes are the same for both, it's simple */
(drPutWaveformYVec newWave (drGetWaveformYVec yVar))
/* otherwise need to use value() to interpolate */
(let (xVec yVec len)
(setq xVec (drGetWaveformXVec xVar))
(setq len (drVectorLength xVec))
(setq yVec (drCreateVec (drGetWaveformYType yVar) len))
(for ind 0 (sub1 len)
(drAddElem yVec (value yVar (drGetElem xVec ind)))
)
(drPutWaveformYVec newWave yVec)
)
)
newWave
)
)

Regards,

Andrew.

 

Hi Andrew,

Unfortunately I don't have the possibility to work with IC50.

But your SKILL function is maybe the beginning of a solution to my problem.

I works very well when I use normal waveform expressions like

XPLOTVAL= v("/XOUT")
YPLOTVAL=v("/SIGNALOUT")
plot(abChangeXAxis(YPLOTVAL XPLOTVAL) )

for example

But when I try to use your procedure in combination with the clip function
like

XPLOTVAL= clip(v("/XOUT") 400n 1u)
YPLOTVAL=clip(v("/SIGNALOUT") 400n 1u)
plot(abChangeXAxis(YPLOTVAL XPLOTVAL) )

it doesn't work anymore

I tried to puzzle out how to fix your routine to get it working with the
clip command, but I lack of the know-how in SKILL programming to do this in
an acceptable time.

To you have a clue?

Best regards

Norman

 

Hi Norman,

Apologies for the delay on getting to this one - I'd just not had a chance to
experiment.

Anyway, for me it worked...

I ran the following simulation:

// eye diagram tester
v1 (1 0) vsource type=sine freq=1M ampl=1 damp=10k
v2 (2 0) vsource type=pulse rise=999n fall=1n width=0 period=1u
r1 (1 0) resistor r=1k
r2 (2 0) resistor r=1k

tran1 tran stop=100u maxstep=10n

And then did the following OCEAN script:

load("abChangeXAxis.il")
simulator('spectre)
openResults("./eye.raw")
selectResults("tran1-tran")
c=abChangeXAxis(v("1") v("2"))
plot(c)
newWindow()
d=clip(v("1") 40u 80u)
e=clip(v("2") 40u 80u)
f=abChangeXAxis(d e)
plot(f)

and everything worked OK (in IC446 too).

Andrew.