Forum Discussion

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

NCO Megacore Phase Adjust

Hello I am using the Altera Megacore NCO Compiler and need to dinamically adjust the phase of the generated sine wave. The core has an input called phase_mod_i[] which is used for this purpos...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
19 years ago

if you read equation 2 on page 37 in nco manual (7.1version): fo=0, fFm=0 fiDither=0, only fiPM=phi_mod_i remains as a phase contribution, so the phase no longer advances with time (clock) factor nT. But you can basically see the answer to your original question from your simulation that a phase_mod_i=10000..0 is pi because sin(0)=sin(pi)=sin(-pi)=0. The value for phase_mod_i=1111111...11 and any other values for that matter, should be easy to read off your simulation as well but it is not visible on your dump. Equation (2) shows that it is linear. Does'nt that answer your original question?