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yaxazaa

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how to use noise_table function
Apr 14^th, 2006, 7:04pm

Could someone explain more detail about how to use noise_table function? My understanding is that the output should be defined as electrical, is that right? For example, I have a table of phase noise verse frequency. The table should be:

phase_noise <= noise_table ({

1 -10
10 -50
1k -89
1m -120
....
});

How do I call it in the top level? If I call the noise table, but try to conveter them to rad^2/hz, can someone tell me how to do it? Besides this, if I want the phase error which is "rad", how should I integrated them in time domain?

Thanks,

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jbdavid Community Fellow Offline Posts: 378 Silicon Valley	Re: how to use noise_table function Reply #1 - Apr 21^st, 2006, 1:48am you will have an output node that needs to have the noise on it.. real phasenoise; ... analog begin ... phasenoise = noise_table( .... V(out) <+ transition(in?vhi:vlo, 0, trf, trf) + phasenoise; -- When NOT running a noise analysis phasenoise = 0 so contributes NOTHING to the output.. Jonathan
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yaxazaa

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Re: how to use noise_table function
Reply #2 - Apr 21^st, 2006, 10:59pm

Actually what I am really interested is the phase noise affects time domain information which is jitter. Detailly here is the steps but how to implement:

1. After read in an three columns' table of frequency vs phase noise, and slope of phase noise information, if my compiler doesn't have "scanf" function, how do I do line by line reading in and manuplation?

2. How do I integrate phase noise between certain frequencies in time domain? For example, do integration of ( (phase noise/10) * (frequency/fc)**phase_noise_slope) from frequency1 to frequency2, which fc is a constant.

3. After the step 2, then this will be phase uncertainty. Can I just add it to the time domain signal as some kind of jitter concept?

Thanks.

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Geoffrey_Coram

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Re: how to use noise_table function
Reply #3 - Apr 25^th, 2006, 5:19am

yaxazaa wrote on Apr 21^st, 2006, 10:59pm:

Actually what I am really interested is the phase noise affects time domain information which is jitter.

The short answer is: you can't use noise_table to affect time domain information (jbdavid's post implies this, but says it differently).

A while ago, I found a couple papers at the IEEEXplore web site on implementing 1/f-like noise in the time domain.

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If at first you do succeed, STOP, raise your standards, and stop wasting your time.

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yaxazaa New Member Offline Posts: 6	Re: how to use noise_table function Reply #4 - Apr 25^th, 2006, 8:25pm Could you post the paper here please? Thanks.
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neoflash

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Posts: 397

Re: how to use noise_table function
Reply #5 - Oct 29^th, 2009, 10:13am

yaxazaa wrote on Apr 14^th, 2006, 7:04pm:

Could someone explain more detail about how to use noise_table function? My understanding is that the output should be defined as electrical, is that right? For example, I have a table of phase noise verse frequency. The table should be:

phase_noise <= noise_table ({

1 -10
10 -50
1k -89
1m -120
....
});

How do I call it in the top level? If I call the noise table, but try to conveter them to rad^2/hz, can someone tell me how to do it? Besides this, if I want the phase error which is "rad", how should I integrated them in time domain?

Thanks,

Can we load the vector from a file in verilogA, instead of manually input them in the noise_table() function?

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Geoffrey_Coram Senior Fellow Offline Posts: 1999 Massachusetts, USA	Re: how to use noise_table function Reply #6 - Nov 2^nd, 2009, 5:35am Please see http://www.designers-guide.org/Forum/YaBB.pl?num=1202431856/0#7
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