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Visitor sadeesh123
Registered: ‎09-10-2019

Frequency varying by switches

Hi all, 

I am try to develop a signal generator using FPGA, I need to controll the frequencies of the wavee forms using swithech or by volume controller(variable resistor),.

Please guid me......

Thank you.


0 Kudos
3 Replies
Registered: ‎06-21-2017

Re: Frequency varying by switches

You can use the switches to determine how to step through a sine wave look up table.  For instance, assuming you are normally adding one to the address of the table.  If you use a switch to tell if you should add two, you will go through the table twice as fast and the frequency of the output will double. 

The DDS IP is very good for this.  If you generate one with a phase increment input, this is essentially what that input controls.  The resolution of the frequency control is dependent on the phase width.

Scholar dgisselq
Registered: ‎05-21-2015

Re: Frequency varying by switches


@bruce_karaffagave a pretty good answer.  If you want to see some more math behind it, you can check out this article.


Scholar drjohnsmith
Registered: ‎07-09-2009

Re: Frequency varying by switches

what level you starting from ?


have you generated your own code an dprogrammed FPGAs before, what lanuguage you using ? VHDL / Verilog / HLS ?

Do yo have a board which you want to use ?

what frequency range you looking at ? how many bits ? do yoa want square / sine / triangle waves ?

Are you looking for an analog output or a digital one, what format ?


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