基于VHDL语言的交通灯控制器设计

基于VHDL语言的交通灯控制器设计2009年06月18日 星期四 20:38设计要求1、显示一个方向的绿、黄、红的指示状态。2、特殊情况按键能实现特殊的功能，计数器停止计数并保持在原来的状态，显示红灯状态。 特殊状态解除后能继续计数.3、复位按键实现总体计数清零功能。4、实现正常的倒计时功能. 用数码管作为倒计时显示, 显示时间为绿灯17s,黄灯3s红灯20s。|-|-|-| 绿灯 |黄灯| 红灯 |设计思想 首先由晶振产生出发信号，由控制器处理成1HZ的时钟，利用此时钟进行计数，通过判断计数的值来控制交通灯的亮灭。通过每种灯亮的时间总数和计数值比较得到数码管应该显示的数值，利用分位程序将其分成十位和个位。通过译码电路来实现数码管的显示。 本实验所使用的芯片为EPM7128SLS84-6，实体逻辑单元为64点，结构体逻辑单元为128点，是一种小型芯片。软件 本实验使用MAXplus II 10来进行程序的编写，编译，仿真以及下载。在实验中发现其功能虽然使用，但仍有地方需要改进，不支持MOD取余运算。(源程序) *在MAX+plus II中，汉字很容易出现乱码，建议大家用英文，这里为了考虑到读者的习惯，因此在写论文时都译成中文Library IEEE;Use IEEE.std_logic_1164.all;Entity redgreen isPort( clock_in:in std_logic; hold_state:in std_logic; reset_state:in std_logic; led_red，led_green，led_yellow:out std_logic; select_en:buffer std_logic; select_display:out std_logic_vector(0 to 6);end;Architecture half of redgreen isconstant loop_hz:integer:=800000; -一根据晶振实际频率算出来signal count_time:integer range 0 to loop_hz;signal clock_buffer:std_logic;signal clock_out:std_logic;signal count_num:integer range 0 to 40;signal display_num:integer range 0 to 20;signal display_shi:integer range 0 to 9;signal display_ge:integer range 0 to 9;constant loop_time:integer:=40;个循环周期的时间constant red_time:integer:=20; -红灯的时间constant green_time:integer:=17; -绿灯的时间constant yellow_time:integer:=3; -黄灯的时间begin process(clock_in) -分频进程 begin if rising_edge(clock_in) then if count_time=loop_hz then count_time=0; clock_buffer=not clock_buffer; else count_time=count_time+1; end if; end if; clock_out=clock_buffer; -输入1HZ的频率 end process; process(reset_state，clock_out) -计数进程 begin if reset_state=1 then -重启后计数归零 count_num=0; elsif rising_edge(clock_out) then if hold_state=1 then -紧急时计数占停 count_num=count_num; else if count_num=loop_time-1 then count_num=0; else count_num=count_num+1; end if; end if; end if; end process; process(clock_out) -交通灯显示 begin if falling_edge(clock_in) then if hold_state=1 then -占停时红灯亮 led_red=1; led_green=0; led_yellow=0; else if count_num display_num=green_time-count_num; led_red=0; led_green=1; led_yellow=0; elsif count_num display_num=green_time+yellow_time-count_num; led_red=0; led_green=0; led_yellow=1; else display_num=loop_time-count_num; led_red=1; led_green=0; led_yellow=20 then display_shi=2; display_ge=10 then display_shi=1; display_ge=display_num-10; else display_shi=0; display_ge=display_num; end if; end process; process(clock_in) -数码管显示 begin if falling_edge(clock_in) then select_enselect_displayselect_displayselect_displayselect_display=0000000; end case; if select_en=1 then select_enselect_displayselect_displayselect_displayselect_displayselect_displayselect_displayselect_displayselect_displayselect_displayselect_displayselect_display=0000000; end case; end if; end if; end process;end;-由于时间和硬件限制，这个程序仅仅实现了一路交通灯，用类似的方法可以写出两路交通灯的程序。library ieee;use ieee.std_logic_1164.all;entity redgreen isPort( clock_in:in std_logic; hold_state:in std_logic; reset_state:in std_logic; led_red,led_green,led_yellow:out std_logic; select_en:buffer std_logic; select_display:out std_logic_vector(0 to 6);end;architecture half of redgreen isbeginsignal count_time:integer range 0 to 800000;signal clock_buffer:std_logic;signal clock_out:std_logic;signal count_num:integer range 0 to 40;signal display_num:integer range 0 to 20;signal display_shi:integer range 0 to 9;signal display_ge:integer range 0 to 9;constant loop_time:integer:=50; constant red_time:integer:=25; constant green_time:integer:=20; constant yellow_time:integer:=5; begin process(clock_in) begin if rising_edge(clock_in) then if count_time=loop_hz then count_time=0; clock_buffer=not clock_buffer; else count_time=count_time+1; end if; end if; clock_out=clock_buffer; end process; process(reset_state,clock_out) begin if reset_state=1 then count_num=0; elsif rising_edge(clock_out) then if hold_state=1 then count_num=count_num; else if count_num=loop_time-1 then count_num=0; else count_num=count_num+1; end if; end if; end if; end process; process(clock_out) begin if falling_edge(clock_in) then if hold_state=1 then led_red=1; led_green=0; led_yellow=0; else if count_num display_num=green_time-count_num; led_red=0; led_green=1; led_yellow=0; elsif count_num display_num=green_time+yellow_time-count_num; led_red=0; led_green=0; led_yellow=1; else display_num=loop_time-count_num; led_red=1; led_green=0; led_yellow=20 then display_shi=2; display_ge=10 then display_shi=1; display_ge=display_num-10; else display_shi=0; display_ge=display_num; end if; end process; process(clock_in) begin if falling_edge(clock_in) then select_enselect_displayselect_displayselect_displayselect_display=0000000; end case; if