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Altera_Forum's avatar
Altera_Forum
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14 years ago

NCO MegaCore Function

Hi,

If I want to generate the fixed amplitude and Fixed Frequency statble Sine Wave, is NCO MegaCore Function is the right choice?

Outof the following Generation Algorithm

Small ROM

Large ROM

CORDIC and

Multiplier-Based

Which one gives the Most Stable Frequency Output?

-- megafunction wizard: %NCO v11.0%

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    the different generation algorithms are largely a resource/time trade off

    if you have lots of extra RAM in your design, choose one of the ROM based NCOs

    if you have lots of logic leftover use a parallel CORDIC

    if you've got a high clock rate but low sample rate use a serial CORDIC

    if you've got some multipliers left over use a multiplier based

    a common specification for NCOs is spurious free dynamic range SFDR. you can get an idea of what you can achieve in the MegaWizard when you vary the parameters