文档介绍：西安邮电学院可编程逻辑实验报告系别通信系学号Xxxxxxxx成绩实验日期2009-12-13班级通工0702姓名高原教师签字实验名称 八、计数器设计一:。。二:实验所用仪表及主要器材MAX+PLUSII软件等三:实验原理简述(源程序、真值表、原理图)模24计数器源程序:libraryieee;;;entitye8_counterisport(en:instd_logic;clear:instd_logic;clk:instd_logic;cout:outstd_logic;qd1,qd0,qs3,qs2,qs1,qs0:outstd_logic);ende8_counter;architecturef2ofe8_counterissignalcounter_h:std_logic_vector(1downto0);signalcounter_l:std_logic_vector(3downto0);begincout<='1'when(counter_h="10"andcounter_l="0011"anden='1')else文档来自于网络搜索'0';process(clk,clear)beginif(clear='1')thencounter_h<="00";counter_l<="0000";elsif(clk'eventandclk='1')thenif(en='1')thenif(counter_h="10"andcounter_l="0011")thencounter_h<="00";counter_l<="0000";elsif(counter_l="1001")thencounter_l<="0000";counter_h<=counter_h+1;elsecounter_l<=counter_l+1;endif;endif;endif;endprocess;qd0<=counter_h(0);qd1<=counter_h(1);qs0<=counter_l(0);qs1<=counter_l(1);qs2<=counter_l(2);qs3<=counter_l(3);endf2;真值表:enClkclearQs3Qs2Qs1Qs0Qd1Qd0count0↑100000001↑000000001↑000010001↑000110001↑000100001↑001100001↑001010001↑001010001↑011000001↑010100001↑010110101↑000110101↑00000010