Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

NCO Frequency modualtion

Hi, I am trying to make a frequency sweeper with an NCO. Can anyone tell me how the modulation input into the NCO works. I want it sweep from 1MHZ to 48MHZ? Thank you in advance.
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

Hi,

If you mean generate frequencies 1MHz to 48MHz:

For altera NCO with accumulator width set at 32 bits running and running at a sampling frequency of Fs:

tuning word = 2^32 * freq(MHz)/Fs(MHz)

so you need to generate the tuning words for freq = 1Mhz up to 48MHz in steps that you choose.

If you mean modulate an input of 1MHz to 48MHz then just connect your input to the modulation input.