|
Message
From: tcoffman_az@h...
Date: Tue, 22 Jan 2002 00:15:46 +0100
Subject: Re: [oc] SNR Calculation using CADENCE SpectreS tool
Hello Lokesh,
You've probably found the answer, but just in case:
Use the OCEAN command, sample and ocnPrint.
For example,
You have a bit stream from your sigma-delta that you'd like to post-
process in Matlab, but the Cadence produces too many points at the
transitions of each pulse. I used that following command in the CIW:
ocnPrint( ?output "/users/you/filename" sample(VT( "/OUT1" ),
20n,340u,"linear",78.125n) )
This sigma-delat has a sample clock of 12.8MHz, hence the 78.125n
sampling. I sampled from 20n to 340u in linear steps and printed the
results to a file, /users/you/filename. The bit stream is a transient
voltage on node "/OUT1".
I hope this helps. It worked very well for me.
Regards,
Tim
----- Original Message -----
From: electronicszone@y...
To: cores@o...
Date: Fri, 3 Aug 2001 16:19:18 +0200
Subject: [oc] SNR Calculation using CADENCE SpectreS tool
>
>
> Dear Sir,
> I am working on a Sigma-delta ADC.
> Currently I am working on CADENCE spectreS tool to
> simulate the modulator.
> I have a
> second order modulator . The bandwidth of the input is 12.5MHz. The
> oversampling ratio is only four (so sampling freq. is 100MHz). I am
> working on a cascaded (MASH) modulator in which the second stage
is
> a 10-bit Pipelined ADC. The flash ADC inside the modulator is a
> 4-bit one. Currently, I have designed the 2nd order modulator using
> Switched capacitor filters. Now, I want to calculate the Signal to
> Noise ratio at the output of the Modulator. Can you please help me
> how to calculate SNR using CADENCE? Since, I have just started
> working on CADENCE, i don't know much the features of this tool.
> While doing its behavioral
simulation in MATLAB, i used the
> PSD command in the MATLAB and since I know the input signal
> frequency, I calculated the signal power and the rest as the Noise
> power to get the SNR. I thought to use that SNR routine only (as i
> used in MATLAB) to calculate the SNR of the output of the modulator
> generated in CADENCE spectreS tool. But the problem is that this
> tool, during its transient analysis, does not generate samples at
> regular interval. So, i cant use the PSD command available in
> MATLAB to calculate the PSD of the output of the modulator to
> calculate the SNR.
> Sir, please give me a suitable solution for the same.
> waiting for a positive reply.
> Thanking You
> Yours sincerely
> Lokesh Kumath
>
|
 |
Browse
