packagecpu.vhd

debussy中文使用手册

library ieee;
use ieee.std_logic_1164.all;
-- use ieee.numeric_std.all;
package packageCPU is

    function to_natural(addr : in std_logic_vector) return natural;
    function is_zero(data : in std_logic_vector) return BOOLEAN;
    function is_zero(data : in bit_vector) return BOOLEAN;


---------------------std_logic_signed.vhd
--    function "+"(L: std_logic_vector; R: std_logic_vector) return std_logic_vector;
--    function "+"(L: STD_LOGIC_VECTOR; R: INTEGER) return STD_LOGIC_VECTOR;
--    function "+"(L: INTEGER; R: STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;

end;

-----------------------------------------------------------------------
library ieee;
use ieee.std_logic_1164.all;
-- use ieee.numeric_std.all;
package body packageCPU is

    function to_natural(addr : in std_logic_vector) return natural is
        variable s : natural;
    begin
        s := 0;
        for i in addr'range loop
            s := s * 2;
            if (addr(i) = '1') then
                s := s + 1;
            end if;
        end loop;
        return s;
    end;

    function is_zero(data : in std_logic_vector) return BOOLEAN is
    begin
	for i in data'range loop
	    if (data(i) /= '0') then
		return FALSE;
	    end if;
	end loop;
	return TRUE;
    end;

    function is_zero(data : in bit_vector) return BOOLEAN is
    begin
	for i in data'range loop
	    if (data(i) /= '0') then
		return FALSE;
	    end if;
	end loop;
	return TRUE;
    end;

    function max(L, R: INTEGER) return INTEGER is
    begin
        if L > R then
            return L;
        else
            return R;
        end if;
    end;
 
 
    function min(L, R: INTEGER) return INTEGER is
    begin
        if L < R then
            return L;
        else
            return R;
        end if;
    end;

--    function "+"(L: STD_LOGIC_VECTOR; R: STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR is
        -- pragma label_applies_to plus
--        constant length: INTEGER := max(L'length, R'length);
--        variable result  : STD_LOGIC_VECTOR (length-1 downto 0);
--    begin
--        result  := SIGNED(L) + SIGNED(R); -- pragma label plus
--        return   std_logic_vector(result);
--    end;

--    function "+"(L: STD_LOGIC_VECTOR; R: INTEGER) return STD_LOGIC_VECTOR is
        -- pragma label_applies_to plus
--        variable result  : STD_LOGIC_VECTOR (L'range);
--    begin
--        result  := SIGNED(L) + R; -- pragma label plus
--        return   std_logic_vector(result);
--    end;

--    function "+"(L: INTEGER; R: STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR is
        -- pragma label_applies_to plus
--        variable result  : STD_LOGIC_VECTOR (R'range);
--    begin
--        result  := L + SIGNED(R); -- pragma label plus
--        return   std_logic_vector(result);
--    end;

end;