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Design >> Mixed-Signal Design >> Calculate INL DNL SNR by .measure command
https://designers-guide.org/forum/YaBB.pl?num=1133245382

Message started by rehzad-zhao on Nov 28^th, 2005, 10:23pm

Title: Calculate INL DNL SNR by .measure command
Post by rehzad-zhao on Nov 28^th, 2005, 10:23pm

hi,
Now I am designing an 10bits pipelineADC.
The .measure command In Hspice can make ADC digital
output to a text file.
How to edit .measure command file to Matlab to calculate INL DNL SNR SFDR and more something?
Thinks

Title: Re: Calculate INL DNL SNR by .measure command
Post by packiaraj on Nov 29^th, 2005, 3:09am

Hi,
It should not be difficult if u know that Spectre-IC5141 comes with VerilogA models for measuring INL and DNL. I feel its bit difficult with .measure statement. In "ahdlLib" u can find "adc_dnl_8bit" and "adc_inl_8bit" Verilog A models that can write the INL and DNL values for Individual Codes of ur ADC. These models can be included in deck file as instances for calculating INL and DNL during simulation.

Thanks,
Packiaraj.V.

Title: Re: Calculate INL DNL SNR by .measure command
Post by rehzad-zhao on Nov 30^th, 2005, 2:32am

Thinks Packiaraj.V.,but I know little about VSpectre-IC5141. I always use the eda tool Hspice.
Rehzad

Title: Re: Calculate INL DNL SNR by .measure command
Post by ywguo on Nov 30^th, 2005, 6:22pm

Dear Zhao,

You could write a matlab program to calculate any parameters of the ADC after you record the output of the ADC.

Theoretically, you can record the output using .measure, .print and maybe other cards. :)

Best regards,
Yawei

Title: Re: Calculate INL DNL SNR by .measure command
Post by rehzad-zhao on Dec 2^nd, 2005, 2:33am

Thinks Yawei, I attempt to do it now. Could you provide some details about what you have said. Or give me some document about it. My email is:
rehzadzhao@yahoo.com

Best regards
zhao

Title: Re: Calculate INL DNL SNR by .measure command
Post by jim on Dec 28^th, 2005, 5:39am

Dear Yawei ,

Could you please provide some details about how to record ADC digital output to a text file using .measure, .print and how to calculate INL DNL...using Matlab? My email is: fujj_2003@163.com

Thanks a lot!

Best Regards,

Jim

Title: Re: Calculate INL DNL SNR by .measure command
Post by chuzi on Dec 28^th, 2005, 11:34pm

Rehzad and Jim,
I am just doing the same thing you do. My way is use .stim to collect data into a text file, then import to matlab, you can find .stim in hspice manual.
hope it helps,
chuzi

Title: Re: Calculate INL DNL SNR by .measure command
Post by jim on Dec 29^th, 2005, 2:28am

Hi chuzi,

Thanks for your reply, Could you please provide a example about using .stim to collect data into a text file for me? Thanks in advance.

Best Regards,

Jim

Title: Re: Calculate INL DNL SNR by .measure command
Post by chuzi on Dec 29^th, 2005, 5:07pm

Hi Jim,
I use it in this way:
.stim tran VEC filename=SDADCtest.data ovar1=v(y1) ovar2=v(y2) ovar3=v(y3) from=10us to=1010us +npoints=20001
.tran 100p 1010us
VEC means vector, from=10us is circuits settle time, npoints=20001 is the FFT's NP, then I choose 16384 points from it.
Hope it helps.
Best regards.
chuzi

Title: Re: Calculate INL DNL SNR by .measure command
Post by jim on Dec 29^th, 2005, 6:29pm

Hi chuzi,

Thanks a lot for your help!

Best Regards,

Jim

Title: Re: Calculate INL DNL SNR by .measure command
Post by jim on Feb 25^th, 2006, 2:58am

Hi chuzi,

I use the method which you mention above, but Hspice didn't produce .data file.

BTW, is the .data file Binary code file?

Thanks in advance.

Best Regards,

Jim