Wave DAC component idea

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Anonymous
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 Hi all

   

Wave DAC component is very interesting for me. Is possible make this component with some modiffier ? (like add, multi, FM, AM, RM - this is ideal for audio synthesis)

   

Kamil

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Bob_Marlowe
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The WaveDAC is a very good example of combining the elements of a PSoC to form something new.

   

It is made of:

   

A table of pre-defined 8-bit values in memory,

   

a DMA-Channel

   

And a DAC.

   

The DMA-Channel is configured to continuosly transfer the table to the DAC without any CPU. That's all

   

So the only point to modify would be the table in memory, where you may dynamically set / alter some of the values.

   

 

   

Hope that helps

   

Bob

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Anonymous
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Hi Kamil.

   

 

   

As Bob has already mentioned, you can use the WaveDAC component according to your requirement.

   

There is an application note which explains Amplitude Modulation and Demodulation the "PSoC Way" using Mixer component as peak detector unit.

   

This application note is available at http://www.cypress.com/?rID=44407

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Anonymous
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Hi all

   

 

   

Thanks info and usefull example.

   

 

   

Kamil

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ETRO_SSN583
Level 9
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The DAC has an 8 bit trim register that can be used to create a multiplying DAC,

   

however my understanding is it only trims +/- 25%, so, for example, AM modulation

   

would not be able to achieve 100% modulation.

   

 

   

This might help - http://www.cypress.com/?app=forum&id=2232&rID=56222

   

 

   

And this http://www.psocdeveloper.com/forums/viewtopic.php?f=42&t=6868&p=32224&hilit=multiplying+dac#p32224

   

 

   

Regards, Dana.

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ETRO_SSN583
Level 9
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One more reference on trim register -

   

 

   

http://www.cypress.com/?app=forum&id=2233&rID=53541

   

 

   

Regards, Dana.

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HeLi_263931
Level 8
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You can look at http://hendriklipka.de/misc/dds.cywrk.Archive02.zip , which implements a VCO based on the WaveDAC idea on the PSoC5 (-050 board). I'm currently working on extending it by implementing a numerically controlled oscilator to achieve higher precision.

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ETRO_SSN583
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AM is basically modifiy sine/cos/complex waveform table with a multiplication applied to its retrieved entries.

   

Phase modulation is modifiy the index into the table.

   

FM modulation is alter the table retrieval rate.

   

http://www.analog.com/static/imported-files/tutorials/MT-085.pdf

   

 

   

Regards, Dana.

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Anonymous
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 Hi Dana

   

 

   

Very thanks info about it.

   

 

   

Kamil

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Anonymous
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 What is the maximun signal frecuency that can be achieved using waveDAC component?

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ETRO_SSN583
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Hardware wise its limited by settling time of the DACs.

   

 

   

In the case of IDAC thats 100 nS, VDAC 1 uS. Thats per sample,

   

multiply that times # samples in waveform table.

   

 

   

Regards, Dana.

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ETRO_SSN583
Level 9
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Keep in mind, if table size real small, like 2 samples, you might

   

have a thruput limitation in writing values to the DAC, in turn that

   

would limit frequency.

   

 

   

Regards, Dana.

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