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KCMurphy's avatar
KCMurphy
Icon for Occasional Contributor rankOccasional Contributor
4 years ago

CORDIC rotator angle input units

The documentation does not state what the input angle units are.

From the IP GUI, it looks like they might be radians, even though 1.0000 = 2pi radians (or the signed equivalent) is a much better way to do a CORDIC, allowing a quick bit test for quadrant on angle inputs, and quick truncation of excess turns on arctan.

Are the units actually radians, where 3243F (b16) is 180 degrees?

2 Replies

  • SyafieqS's avatar
    SyafieqS
    Icon for Super Contributor rankSuper Contributor
    4 years ago

    Kevin,


    Can you show me a snapshot might be good, are you referring to?


  • KCMurphy's avatar
    KCMurphy
    Icon for Occasional Contributor rankOccasional Contributor
    3 years ago

    When I find time, I will post something in detail. But one thing that the Altera design misses: One of the primary reasons people use a CORDIC is to get rid of the terribly difficult number "pi". Particularly in binary logic. It is actually not part of a CORDIC calculation unless someone makes it so.

    A very clear description of CORDIC can be found here: http://dspguru.com/dsp/faqs/cordic/