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MMorr30's avatar
MMorr30
Icon for New Contributor rankNew Contributor
6 years ago

Basic NCO IP component for Cyclone IV cannot get simple sinewave

Hi,

I cannot get a simple sinewave out of the NCO IP on the cyclone 4. Below is the component from the IP Parameter editor.

Here is my instantiation:

nco u0k (

.clk (CLK_125),

.reset_n(1),

.clken (1),

.phi_inc_i (34359738),

.fsin_o (sin_out),

.fcos_o (),

.out_valid (ovalid)

);

I am using the DE2i_150 board, Quartus 16.1, and the ADA board from Terasic for my DAC. I simply cannot get a sine wave out. Here is the best I can get:

Is my phase increment correct? It says so in the ip parameter editor. Do I need some sort of frequency modulation added? Is there a gain setting Im unaware of?

Thank you :)

2 Replies

  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor
    6 years ago

    Hi,

    sorry for the delay as the case has just been routed to me. As I understand it, you are observing some issue with the CIV NCO IP output. Just would like to check with you if you have had a chance to run a Modelsim simulation with your NCO IP to ensure the output is something matching your expectation? This would be helpful to isolate any functional behavior prior to hardware testing. In hardware, there are a number of other dependencies other than NCO IP.

    Please let me know if there is any concern. thank you.