LIBRARY IEEE; USE IEEE.std_logic_1164.ALL; ENTITY ThrToEig IS PORT(A,B,C,G1,G2A,G2B:IN std_logic; y:OUT std_logic_vector(7 DOWNTO 0)); END ThrToEig; ARCHITECTURE behave OF ThrToEig IS SIGNAL indata:std_logic_vector(2 DOWNTO 0); SIGNAL G:std_logic_vector(2 DOWNTO 0); BEGIN indata<=C&B&A; G<=G1&G2A&G2B; PROCESS(indata,G) BEGIN IF(G='111')THEN CASE indata IS WHEN"000"=>y<="11111110"; WHEN"001"=>y<="11111101"; WHEN"010"=>y<="11111011"; WHEN"011"=>y<="11110111"; WHEN"100"=>y<="11101111"; WHEN"101"=>y<="11011111"; WHEN"110"=>y<="10111111"; WHEN"111"=>y<="01111111"; WHEN OTHERS=>y<="XXXXXXXX"; END CASE; ELSE y<="11111111"; END IF; END PROCESS; END behave;为什么会编译失败
时间: 2023-12-05 10:07:53 浏览: 35
这段代码存在一个语法错误。在PROCESS语句中,应该使用BEGIN和END来包围CASE语句。修改后的代码如下:
```
LIBRARY IEEE;
USE IEEE.std_logic_1164.ALL;
ENTITY ThrToEig IS
PORT(A,B,C,G1,G2A,G2B:IN std_logic;
y:OUT std_logic_vector(7 DOWNTO 0));
END ThrToEig;
ARCHITECTURE behave OF ThrToEig IS
SIGNAL indata:std_logic_vector(2 DOWNTO 0);
SIGNAL G:std_logic_vector(2 DOWNTO 0);
BEGIN
indata<=C&B&A;
G<=G1&G2A&G2B;
PROCESS(indata,G)
BEGIN
IF(G='111')THEN
CASE indata IS
WHEN"000"=>y<="11111110";
WHEN"001"=>y<="11111101";
WHEN"010"=>y<="11111011";
WHEN"011"=>y<="11110111";
WHEN"100"=>y<="11101111";
WHEN"101"=>y<="11011111";
WHEN"110"=>y<="10111111";
WHEN"111"=>y<="01111111";
WHEN OTHERS=>y<="XXXXXXXX";
END CASE;
ELSE
y<="11111111";
END IF;
END PROCESS;
END behave;
```
此外,还需要确保在文件开头已经正确引入了所需的库文件。