1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374 |
- ----------------------------------------------------------------------------------
- -- Company:
- -- Engineer:
- --
- -- Create Date: 10:12:38 04/13/2021
- -- Design Name:
- -- Module Name: alu - Behavioral
- -- Project Name:
- -- Target Devices:
- -- Tool versions:
- -- Description:
- --
- -- Dependencies:
- --
- -- Revision:
- -- Revision 0.01 - File Created
- -- Additional Comments:
- --
- ----------------------------------------------------------------------------------
- library IEEE;
- use IEEE.STD_LOGIC_1164.ALL;
- use IEEE.STD_LOGIC_UNSIGNED.ALL;
-
- -- Uncomment the following library declaration if using
- -- arithmetic functions with Signed or Unsigned values
- use IEEE.NUMERIC_STD.ALL;
-
- -- Uncomment the following library declaration if instantiating
- -- any Xilinx primitives in this code.
- --library UNISIM;
- --use UNISIM.VComponents.all;
-
- entity alu is
- Port ( A : in STD_LOGIC_VECTOR (7 downto 0);
- B : in STD_LOGIC_VECTOR (7 downto 0);
- Ctrl_Alu : in STD_LOGIC_VECTOR (2 downto 0);
- N : out STD_LOGIC;
- O : out STD_LOGIC;
- Z : out STD_LOGIC;
- C : out STD_LOGIC;
- S : out STD_LOGIC_VECTOR (7 downto 0));
- end alu;
-
- architecture Behavioral of alu is
- signal A9: STD_LOGIC_VECTOR(8 downto 0);
- signal B9: STD_LOGIC_VECTOR(8 downto 0);
- signal ADD: STD_LOGIC_VECTOR(8 downto 0);
- signal SUB: STD_LOGIC_VECTOR(8 downto 0);
- signal MUL: STD_LOGIC_VECTOR(15 downto 0);
- signal SBIS: STD_LOGIC_VECTOR(7 downto 0);
-
- begin
-
- A9 <= "0"& A;
- B9 <= "0"& B;
- ADD <= A9 + B9;
- SUB <= A9 - B9;
- MUL <= A * B;
-
- SBIS <= ADD(7 downto 0) when Ctrl_Alu = "001" else
- SUB(7 downto 0) when Ctrl_Alu = "010" else
- MUL(7 downto 0) when Ctrl_Alu = "011" else
- (others => '0');
- O <= '1' when MUL(15 downto 8) /= "00000000" and Ctrl_Alu = "011" else
- '0';
- C <= '1' when ADD(8) = '1' and Ctrl_Alu = "001" else
- '0';
- N <= '1' when SUB(8) = '1' and Ctrl_Alu = "010" else
- '0';
- Z <= '1' when SBIS = "00000000" and Ctrl_Alu /= "000" else
- '0';
- S <= SBIS;
- end Behavioral;
|