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Altera_Forum
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14 years ago

Counting the position of ones in a binary vector

I want to design a combinatorial circuit for an fpga which will count the position of ones in a 16 bit vector. eg1 if vector is 16'b0000_0000_0011_0101 then output should be 64'h0000_0000_0000_5...
Altera_Forum's avatar
Altera_Forum
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14 years ago

It is sad that in many fora across the web simple solutions get drowned in garbage.

The for loop unfolds to comb logic as follows:

if input(0) = '1' then

....

end if;

if input(1) = '1' then

....

end if;

if input(2) = '1' then

....

end if;

etc. until input(15)

The compiler unrolls it at compile time. It is just for convenience of writing multiple statements.