putin.vhd

此程序能够实现4位二进制乘法

LIBRARY IEEE; 
USE IEEE.STD_LOGIC_1164.ALL; 
USE IEEE.STD_LOGIC_ARITH.ALL; 
USE IEEE.STD_LOGIC_UNSIGNED.ALL; 

ENTITY PUTIN IS
    PORT(CP0,CP1:IN STD_LOGIC;
           DATA:IN STD_LOGIC_VECTOR(4 DOWNTO 0);
           X,Y:OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
           XSIGN,YSIGN:OUT STD_LOGIC);
END PUTIN;

ARCHITECTURE PART1 OF PUTIN IS
   BEGIN
PROCESS(CP0,CP1,DATA)
BEGIN
IF CP0='1' THEN 
      X<=DATA(3 DOWNTO 0);
       XSIGN<=DATA(4);
          ELSIF CP1='1' THEN
          Y<=DATA(3 DOWNTO 0);
            YSIGN<=DATA(4);   
          END IF;
          END PROCESS;
        END PART1;