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Altera_Forum
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8 years ago

Fully Synthesizable Fix Point package

Hi, Great- I'v just learned how to use fully synthesizable floating point arithmetic calculation (using MegaFunction/IP cores). Now, how can I implement fully synthesizable Fix point calculation? ...
Altera_Forum's avatar
Altera_Forum
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8 years ago

in VHDL - its simple, especially if you use the fixed point package: 


use ieee.fixed_pkg.all;
....
signal a : sfixed(7 downto -8); -- 1 sign bit, 7 integer bits, 8 fraction bits - ie. integer offset by 2^8
signal b : sfixed(15 downto -16);
...
b <= a*a;

this can all be done with the numeric_std package, but you need to keep track of the offset yourself.