how to implement digital VCO in FPGA board ?

[clarity]

digital VCO

hello people !
could u give me a basic idea how to implement digital VCO in FPGA board ?
i would highly appreciate any suggestions . thank you in advance.

 

[RBB]

digital VCO

Look into NCO or numerically controller oscillator. It's basically an integrator that overflows at some rate. The MSB of the integrator is the output & you can change the frequency by changing the integrator input.

 

[seesea11]

Re: digital VCO

generally the NCO is implemented with LUT which contains the sin(cos) value. u use the output of integrator as the address. the frequency will be determined by the integrator step.

 

[RBB]

digital VCO

Yes a LUT is needed to generate sin/cos, but if just need a clock, then only the NCO is needed.

 

[clarity]

digital VCO

thank you a lot ... RBB & Seesea for your quick response .
i got some ideas, thanx. i am a beginner ... u guys must be something similar with the image i have uploaded.
Cud u plz help me where cud i find some reference or example to model NCO ??


thanking u in advance.

 

[seesea11]

Re: digital VCO

u may google many of it.
Following link is one of them :
etrij.etri.re.kr/Cyber/servlet/GetFile?fileid=SPF-1119247833613