bcdtob4.vhd

来自「ProtelDXp 实现计算器功能」· VHDL 代码 · 共 32 行

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY BCDTOB4 IS
PORT
(
	NUM	:IN STD_LOGIC_VECTOR(3 DOWNTO 0);
	CO	:OUT STD_LOGIC_VECTOR(15 DOWNTO 0));
END;
ARCHITECTURE A OF BCDTOB4 IS
BEGIN
	PROCESS
BEGIN
CASE NUM IS
		WHEN"0000"=>CO<="0000000000000000";
		WHEN"0001"=>CO<="0000001111101000";
		WHEN"0010"=>CO<="0000011111010000";
		WHEN"0011"=>CO<="0000101110111000";
		WHEN"0100"=>CO<="0000111110100000";
		WHEN"0101"=>CO<="0001001110001000";
		WHEN"0110"=>CO<="0001011101110000";
		WHEN"0111"=>CO<="0001101101011000";
		WHEN"1000"=>CO<="0001111101000000";
		WHEN"1001"=>CO<="0010001100101000";
		WHEN OTHERS=>CO<="0000000000000000";
END CASE;
END PROCESS;
END;