iteration Vs LUT table entry vs accuracy in Cordic

Hello, I wanted the relationship between the number of iteration vs LUT table entry. Because i wanted to estimate the arc tan to a accuracy of 1 microradians. In my simulation i found that even if the iteration is around 25 iteration i could not achieve the 1 microradian accuracy.

My LUT i have represented using 32 bit and the two number whos atan is to be obtained is also 32 bit(all fixed point).

Please suggest a solution with regards praveen

Reply to
praveen
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Somewhere I have a databook from many years ago with a ROM look-up table for sine. This was when ROMs were much smaller than today, and pretty much the way it worked was to have one that was the high bits of the sine, and another that did linear interpolation.

What domain and range do you expect for your arctan? For smaller values it shouldn't be too hard, but for larger values it gets much harder. What form is the input in, and what form do you expect the output to be?

-- glen

Reply to
glen herrmannsfeldt

Go to my web site,

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look at my article "Quadratic Interpolation in Forth", and even it the article itself gives you no ideas, there's a link at the top that may.

Jerry

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Engineering is the art of making what you want from things you can get.
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Reply to
Jerry Avins

That link seems to be brokken--it redirects to .

KP

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Remove _me_ for e-mail address
Reply to
Ken Prager

Copy/paste mysteriously failed. (Operator error, but how?) The correct URL is

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or
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or even
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Jerry

--
Engineering is the art of making what you want from things you can get.
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Reply to
Jerry Avins

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