Hey, I do understand how to convert a binary number into a decimal number but the following code thats supposed to do that doesnt make sense. I mean lets sat we have a binary number 10, then v(i) would be 0, so result stays 0. Upon the next iteration v(i) will be 1 so result will be 0 + 1 . The loop stops and the function will return the value of result which is 1 and not 2 which is the value of the binary number put into the function. Could someone tell me why I am wrong? This code comes with a university assignment so it should be correct. Thanks. :) ------------------------------------------------------------------------ ------- -- convert std_logic vector v to natural ------------------------------------------------------------------------ ------- FUNCTION s2n(v: std_logic_vector) RETURN natural IS VARIABLE result: natural := 0; BEGIN FOR i IN v'range LOOP result := result * 2; IF v(i) = '1' THEN result := result + 1; END IF; END LOOP; RETURN result; END s2n;

Lets define a signal x : std_logic_vector(1 downto 0); Then x'range will result in (1 downto 0) And so the code FOR i IN v'range LOOP will result in FOR i IN 1 downto 0 LOOP And now, try it once more. First index now is number 1, the second cycle is index 0... The major problem of this "university assigned" code is, that it implicitly assumes, that the vector is ranged with adownto. It will not work as expected with this vector: signal x : std_logic_vector(0 to 1);