Numeric Translation Functions

The numeric translation functions convert the nine std_logic values to numeric binary values (‘0’ or ‘1’) for use in signed and unsigned arithmetic operations. These translation functions convert the values of ‘L’ and ‘H’ to ‘0’ and ‘1’, respectively. Any other values (‘U’, ‘X’, ‘Z’, ‘-’, or ‘W’) result in a warning error (assertion) being generated.

    function to_01 (S: unsigned; XMAP: std_logic := '0') return unsigned;

    function to_01 (S: signed; XMAP: std_logic := '0') return signed;