can someone please help about NCO HDL optimized block. How to generate a simple sine wave with it. I am gettting a single straight line as output for what ever phase increment i use. can someone help how to set sampling frequency as well

iam always getting something like this but not a sine wave

Answer 1

[Bharath Venkataraman]

Attached is a simple NCO which generates a sine wave. Phase increment is set to 4 and accumulator size is 8 bits, so you will see a full period in 2^8/4 = 64 steps.

[Awaiz Khan]

Sir, this shows errors like this. PLEASE HELP!

[Awaiz Khan]

WHAT I REALLY WANT IS sine wave generater using Simulink NCO. output sine wave frequency (selectable among 1Khz,5Khz,10Khz,50Khz,100Khz,200Khz by 3bit inputs) sampling frequency : 10Mhz SFDR : over 85dB pahse offset : 0 frequency resolution : not critical sine output : 14bit

then Synthesizable verilog code via HDL coder

HELP PLEASE!

[Bharath Venkataraman]

It appears that the second input to the NCO HDL Optimized block (validIn) is not connected. You can try connecting a costant block to that input with value set to true and an appropriate sample time.

[Awaiz Khan]

Sir, it still makes errors. I dont know how to solve this up. Can you send your working code to this? It will be very helpful Respected Sir.

[Bharath Venkataraman]

Are you using the model I attached above - nco_simple.slx?

[Awaiz Khan]

Yes !

[Bharath Venkataraman]

I am able to run this model in R2018b without issues. Can you attach the model you are using and which version of MATLAB you are running?