How to change the wave's axis in Hspice and Spectre?

spectre cosmoscope

I want to get the wave like this:
x-axis is 2Id/gm
y-axis is Id.

How should i do in hspice and spectre?

thanks.

how to plot a wave with hspice

For Spectre (Analog Artist)
Plot Id vs. Vgs.
Using calculator plot deriv(Id).
Divide ("/").
In Waveform window select Axis -> X Axis -> Plot vs. and change from "Independent" to "deriv(Id)/Id".
Good luck.

plot on one graph cosmoscope

It is difficult to do X-axis unit change as I know . But it is easy change Y-axis, just use command in awaves .

spectre plot x axis

holddreams said:

I want to get the wave like this:
x-axis is 2Id/gm
y-axis is Id.

How should i do in hspice and spectre?

thanks.

Click to expand...

i do this in that way in hspice and awaves.

first i declare parameter xtmp which is avaiable in params in awaves results browser

.probe xtmp = par('2*i(m1)/gmo(m1)')

thereafter i pull xtmp using middle mouse button to current x-axis

if you knew, how to do it in cosmoscope using calculator, please, let me know

change unit hspice

first
.dc vgs start stop step
.probe par1=par('2*i(m1)/gmo(m1)')

after simulation
Awanwaves->Result Browser->select par1 in curves
then in 'current X-axis', click 'Apply', this change X-axis from 'vgs' to 'par1';
double click i(m1) in Result Browser,you will get
X-axis: par1
Y-axis: i(m1)

hspice 2id/gm

jutek said:

holddreams said:

I want to get the wave like this:
x-axis is 2Id/gm
y-axis is Id.

How should i do in hspice and spectre?

thanks.

Click to expand...

i do this in that way in hspice and awaves.

first i declare parameter xtmp which is avaiable in params in awaves results browser

.probe xtmp = par('2*i(m1)/gmo(m1)')

thereafter i pull xtmp using middle mouse button to current x-axis

if you knew, how to do it in cosmoscope using calculator, please, let me know

Click to expand...

That is a method in spectre. If you want to change x-axis in csope, as I know, there is no good method. I always do like that:
1 plot two waves in same graph, one is A, the other is B
2 if you want to change x-axis to A
3 right click on name of A(on the right side of graph), choose view->horizontal vlue->real
4 then there will be two x-axis in this graph. one the the original, the other is A
It's not convenient like awaves.