本项目介绍如何使用VHDL语言设计一个八选一数据选择器,详细讲解了逻辑原理及代码实现过程,适合初学者学习数字电路与FPGA编程。
八选一数据选择器的VHDL语言完整程序如下:
实体定义:
```vhdl
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
entity MUX8to1 is
Port ( D0 : in STD_LOGIC;
D1 : in STD_LOGIC;
D2 : in STD_LOGIC;
D3 : in STD_LOGIC;
D4 : in STD_LOGIC;
D5 : in STD_LOGIC;
D6 : in STD_LOGIC;
D7 : in STD_LOGIC;
S0, S1, S2, S3: in STD_LOGIC;
Y : out STD_LOGIC);
end MUX8to1;
```
结构体定义:
```vhdl
architecture Behavioral of MUX8to1 is
begin
process (D0,D1,D2,D3,D4,D5,D6,D7,S0, S1, S2, S3)
begin
case (S3 & S2 & S1 & S0) is
when 0000 => Y <= D0;
when 0001 => Y <= D1;
when 0010 => Y <= D2;
when 0011 => Y <= D3;
when 0100 => Y <= D4;
when 0101 => Y <= D5;
when 0110 => Y <= D6;
when others => Y <= D7;
end case;
end process;
end Behavioral;
```
以上代码定义了一个八选一数据选择器,输入为8个数据信号(D0-D7)和4位地址编码(S3-S0),输出是根据地址信号从八个输入中选出的一个。