anyone very familiar with hspice? help on DC measure please!

[sunjiao3]

.meas dc


Dear all,
I encounter a problem in sim with hspice 2004.09. I designed a hysteresis comparator, and, I wanna measure its positive and negtive trig point and thus the width of the hysteresis window in DC sweep. This would be a huge work when I use monte carlo simulation, and what is more, I 'd like get more accurate result. So, how to do it by using .meas?

I've read all the related doc like command_ref. But all examples are give in .meas tran or .meas ac. I think the most "like" command is "find when". So, I use the following command:
.measure DC TH+ find X when v(out)=2.5 fall=1

Here, X is the value of the input signal. But, all I got in *.ms was


$DATA1 SOURCE='HSPICE' VERSION='W-2004.09 '
.TITLE 'comparator_hysteresis************************************'
th+ temper alter#
failed 25.0000 1.0000


So, anyone have the same experience before? Please, give me some suggestion on this command.

 

[Syukri]

hspice measure dc

u got and eror while compling it or the resutlt is not right?

X is a function fall calling subckt, maybe it doesnt understand it..

 

[flushrat]

meas dc

Is X a parameter?
if so, change the X in your measure statement into V(node)

 

[xerxer]

x means hspice

x means subket
voltage express must use v in the beginnig of expression

 

[muldersun]

what x means in hspice

.DC V4 0.4 0.8 0.001
.MEAS DC VLH TRIG V(BGP_RDY) AT=0.4 RISE=1 TARG V(BGP_RDY) VAL='0.1*VS' RISE=1
.DC V4 0.8 0.4 -0.001
.MEAS DC VHL TRIG V(BGP_RDY) AT=0.8 FALL=1 TARG V(BGP_RDY) VAL='0.9*VS' FALL=1
.MEAS DC VHYS PARAM='VLH+0.4-(0.8+VHL)'

This is my file for measure hysteresis voltage.Maybe, it can be referenced for you.

Added after 5 minutes:

.DC V4 0.4 0.8 0.001
.MEAS DC VLH TRIG V(BGP_RDY) AT=0.4 RISE=1 TARG V(BGP_RDY) VAL='0.1*VS' RISE=1
.DC V4 0.8 0.4 -0.001
.MEAS DC VHL TRIG V(BGP_RDY) AT=0.8 FALL=1 TARG V(BGP_RDY) VAL='0.9*VS' FALL=1
.MEAS DC VHYS PARAM='VLH+0.4-(0.8+VHL)'

This is my file for measure hysteresis voltage.Maybe, it can be referenced for you.

If you work in windows, you can find VHYS in .lis file, all corner results are in this file.
If you work in linux/unix , you need to generate .lis by yourself.