Measuring a nodal voltage for some condition

Hi all,

I am new to cadence, and in between my Master thesis project.

i want to measure a nodal voltage v1, when vout is 0.1v
actually I am trying to measure the Transition voltage, in a adc
design.

could any one help me out.

i was going through the oceans script, but couldnt succeed.

Thanks.
dinac

 

VerilogA or AHDL will be a good starting point.

Ozgur

 

In ocean or in the calculator (menu special functions), you can use
the "cross" function to determine when vout reaches 0.1V and then the
"value" function to get the value of v1 at this instant:

value( VT("/v1") cross(VT("/vout"),0.1,1,"either",nil,nil))

Oliver

 

Hi Dinac,

As Oliver mentioned above, ocean is the best way to make this kind of
measurements.
I just wanted to show you where you can find the ocean documentation
should you need it for further measurements.
From the Unix terminal where you've launched Cadence from, you can
launch the OCEAN Reference Manual with the following UNIX command:
acroread $CDSHOME/doc/oceanref/oceanref.pdf

You've got loads of examples and good explanations.

Enjoy,

Riad.

 

Hi all,

Thanks a lot for your help, oliver and Riad

Actually i did use the calculator to determine it.
Then i got the results from the Result-browser to matlab, to plot for
vin vs the Bits ( when vout-fall reaches 0.1 threshold, I used this
method to determine the outbit value ' Hope this method is right' )
and got a nice step for each input.

Could any one help me out in providing a practical-way to determine
the Static Errors, offset, gain and INL, DNL...

thanks for the help again

cheers
dinac

 

Hi Dinac,

The following book got a very nice chapter that explains the things
you're looking for:
Data Converters by Franco Maloberti
http://www.amazon.com/Data-Converters-Franco-Maloberti/dp/0387324852
And then look at Chapter 2: DATA CONVERTERS SPECIFICATIONS

You can give a look at the the designers-guide forum as well:
http://www.designers-guide.org/Forum/

Hope this will help you in getting what you want !
You know where to find us otherwise !

Enjoy yourself !

Riad.

 

Hi all,

Thanks Riad, for the reference, i am still trying to get the book. But
for now, i got some reference from maxim, and i refering to it and
familiarizing. The design is a slow-5-Bit ADC for a temperature
sensor, so i guess only DC specifications play a role.

Actually I am finding a method to calculate just the Transition
Voltges, for each of the Bits,

Meanwhile, I have a some basics clarification in cadence,

a. I want to add some initialization path to the cadence, like setting
a default path of the project directory. Is this defined in cdsenv ? I
tried a lot to search a method to do this.

b. Is it possible to kill a process inside the cadence,like for
exmple, i did run a param sweep for arround 1000 steps and after
that, by mistake i clicked on the Result browser to show me the list
of V1 to a table, and now I want to kill this process alone,
without affecting the cadence to close.

Thanks a lot, actually i am new to cadence, hence i am asking some
basic quesiton ,,...

cheers
dinesh

 

Hi Dinesh,

You can use the following environment variable to specify project
directory in cdsenv file,

asimenv.startup projectDir string "./simulation"

Cheers,
Ranjith