用vhdl
设计
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四输入与门,两种方法2010-11-0122:44碧草cc|分类:其他编程语言|浏览1032次急,谢谢!要过程分享到:检举|2010-11-0218:35提问者采纳第一种方法,程序如下:libraryieee;useieee.std_logic_1164.all;entityand4isport(a,b,c,d:instd_logic;z:outstd_logic);endand4;architecturemediedofand4isbeginz<=(aandb)and(candd);endmedied;第二种方法,程序如下:libraryieee;useieee.std_logic_1164.all;entityand4isport(a,b,c,d:instd_logic;z:outstd_logic);endand4;architecturemediedofand4issignalabcd:std_logic_vector(3downto0);beginabcd<=a&b&c&d;process(abcd)begincaseabcdiswhen"1111"=>Z<='1';whenothers=>z<='0';endcase;endprocess;endmedied;