if(LIGHT==0)
时间: 2023-10-06 21:05:48 浏览: 31
This code appears to be checking if a variable named "LIGHT" has a value of 0. If it does, then some action may be taken in the code that follows. However, without additional context it is difficult to determine exactly what the purpose of this code is.
相关问题
module liushui(clk, rst, led,ctrl); input clk; input rst; input ctrl; output [7 : 0] led; parameter WIDTH =27; parameter COUNT = 99_999_999; reg [WIDTH - 1 : 0] cnt; reg [7 : 0] light; reg flag; always @(posedge clk) begin if (!rst) cnt <= 0; else if (cnt == COUNT) cnt <= 0; else if(ctrl) cnt<=cnt; else cnt <= cnt + 1; end always @(posedge clk) begin if (light == 8'h01) flag <= 1; //left move else if (light == 8'h80) flag <= 0; //rihgt move else ; end always @(posedge clk) begin if (!rst) light <= 8'h01; else if (cnt == COUNT) begin if(ctrl) light<=light; else if (flag) light <= light << 1; else light <= light >> 1; end else ; end assign led = light; endmodule修改代码,添加一个按键,使按键为1时流水灯能够单向运行
可以添加一个输入端口 button,用来输入按键信号。当 button 为 1 时,流水灯单向循环运行;否则,流水灯双向循环运行。修改后的代码如下:
```
module liushui(clk, rst, led, button);
input clk;
input rst;
input button;
output [7:0] led;
parameter WIDTH = 27;
parameter COUNT = 99_999_999;
reg [WIDTH - 1:0] cnt;
reg [7:0] light;
reg [1:0] dir; // 0: right, 1: left
always @(posedge clk) begin
if (!rst)
cnt <= 0;
else if (cnt == COUNT)
cnt <= 0;
else if (button)
cnt <= cnt;
else
cnt <= cnt + 1;
end
always @(posedge clk) begin
if (light == 8'h01) // left move
dir <= 1;
else if (light == 8'h80) // right move
dir <= 0;
end
always @(posedge clk) begin
if (!rst)
light <= 8'h01;
else if (cnt == COUNT)
if (button)
if (dir)
light <= light << 1; // left move
else
light <= light >> 1; // right move
else
if (dir)
light <= light << 1; // left move
else if (light == 8'h80)
light <= 8'h01; // reset to 8'h01
else
light <= light >> 1; // right move
end
assign led = light;
endmodule
```
#include <reg51.h> unsigned char code table[] = { 0xFC, 0x60, 0xDA, 0xF2, 0x66, 0xB6, 0xBE, 0xE0, 0xFE, 0xF6, 0xEE, 0x3E, 0x9C, 0x7A, 0x9E, 0x8E}; unsigned char i, j, flag, num; char Count; bit Sym = 0; sbit nred = P1^2; sbit ngreen = P1^4; sbit nyellow = P1^3; bit red_light = 0; bit yellow_light = 0; bit green_light = 0; void putch(unsigned char n) { SBUF = n; while(TI == 0); TI = 0; } void main() { TMOD = 0X01; EA = 1; ET0 = 1; TH0 = (65536 - 50000) / 256; TL0 = (65536 - 50000) % 256; flag = 0; Count = 0; nred = nyellow = ngreen = 0; num = 0; i = table[Count / 10]; j = table[Count % 10]; putch(i); putch(j); while(1) { if (red_light) { nred = 1; ngreen = 0; nyellow = 0; } if (yellow_light) { nyellow = 1; nred = 0; ngreen = 0; } if (green_light) { ngreen = 1; nred = 0; nyellow = 0; } } } void Timer0() interrupt 1 { flag++; TH0 = (65536 - 50000) / 256; TL0 = (65536 - 50000) % 256; if (flag == 20) { flag = 0; Count--; } if (Count == num) { Count = 10; if (num == 0) { num = 8; nyellow = 0; Sym = ~Sym; } else { nyellow = 0; num = 0; } } i = table[Count / 10]; j = table[Count % 10]; putch(i); putch(j); } void red_light_timer() interrupt 2 { if (red_light) { red_light = 0; yellow_light = 1; } else { red_light = 1; green_light = 0; } } void green_light_timer() interrupt 3 { if (green_light) { green_light = 0; yellow_light = 1; } else { green_light = 1; red_light = 0; } }注释
这是一段基于单片机的红绿灯控制程序。程序通过定时器中断来控制红绿灯的变化,同时使用串口通信将倒计时数码管的数据输出。具体实现如下:
1. 定义了一个包含 16 个元素的 unsigned char 类型的数组 table,用于存储数码管显示的编码。
2. 定义了一些变量,包括 i、j、flag、num、Count、Sym、red_light、yellow_light 和 green_light。
3. 实现了 putch 函数,用于通过串口输出数据。
4. 在 main 函数中进行了一些初始化操作,包括设置定时器模式、使能定时器中断、设置定时器初值、初始化一些变量,并通过 putch 函数将倒计时数码管的初始值输出。
5. 在 while(1) 循环中,根据红绿灯的状态控制相应的引脚输出。
6. 实现了 Timer0 函数,用于定时器中断处理。在函数中实现了倒计时、控制黄灯闪烁等功能,并通过 putch 函数将倒计时数码管的值输出。
7. 实现了 red_light_timer 和 green_light_timer 函数,用于红绿灯的切换。在函数中根据当前灯的状态控制相应的引脚输出。其中,red_light_timer 函数在中断优先级上比 green_light_timer 函数高,因此红灯优先于绿灯。
8. 程序中使用了一些特殊的语法,如 sbit 和 bit 关键字,用于定义单个位的变量,并通过 |= 和 &= 运算符对变量进行读写操作。
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