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Altera_Forum's avatar
Altera_Forum
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15 years ago

How can i use CORDIC ?

Hello i am trying to use the cordic core { http://opencores.org/project,cordic } with no sucess. Say i have a complex number of 4 + 5i. I have inserted 1000 as the Xi input and 1001 as the Yi...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

You can multiply a signed/unsigned with an integer with the numeric_std library. Be careful with multiplying fixed point vectors though, as you will need to shift the result back.

As for your 0 result, it is because with this assignment:

--- Quote Start ---

constant um_terco : signed (40 downto 0) := to_signed(integer(0.3333),41);

--- Quote End ---

0.3333 is converted to the integer 0. You forgot to multiply 0.3333 by the scaling factor.