描述

General Description: 

我使用的 MUX8_5 输入信号全部失效了。我正在使用一个基础原理图编辑器，并面向一个 XC95144 部件。

解决方案

使用以下 VHDL 解决此问题：

library IEEE; 

use IEEE.std_logic_1164.all; 

entity mux8_5is 

端口 ( 

one: in STD_LOGIC_VECTOR (7 downto 0); 

two: in STD_LOGIC_VECTOR (7 downto 0); 

three: in STD_LOGIC_VECTOR (7 downto 0); 

four: in STD_LOGIC_VECTOR (7 downto 0); 

five: in STD_LOGIC_VECTOR (7 downto 0); 

output: out STD_LOGIC_VECTOR (7 downto 0); 

sel: in STD_LOGIC_VECTOR (2 downto 0) 

); 

end mux8_5; 

architecture mux8_5_arch of mux8_5 is 

begin 

process (SEL, one, two, three, four, five) 

begin 

case SEL is 

when "000" => output (7 downto 0)<= one(7 downto 0) ; 

when "001" => output (7 downto 0) <= two (7 downto 0) ; 

when "010" => output (7 downto 0) <= three (7 downto 0) ; 

when "011" => output (7 downto 0) <= four (7 downto 0) ; 

when "100" => output (7 downto 0) <= five (7 downto 0) ; 

when others => NULL; 

end case; 

end process; 

end mux8_5_arch;