单片机第一个点灯程序 -

标题: 单片机第一个点灯程序 [打印本页]

作者: zyscxr 时间: 2024-9-22 17:48
标题: 单片机第一个点灯程序
#include "reg51.h"

typedef unsigned char BYTE;
typedef unsigned int WORD;

//-----------------------------------------------

/* define constants */
#define FOSC 11059200L

#define T1MS (65536-FOSC/12/1000) //1ms timer calculation method in 12T mode

/* define SFR */
sbit TEST_LED = P1^0;             //work LED, flash once per second

/* define variables */
WORD count;                      //1000 times counter

//-----------------------------------------------

/* Timer0 interrupt routine */
void tm0_isr() interrupt 1
{
TL0 = T1MS;                   //reload timer0 low byte
TH0 = T1MS >> 8;             //reload timer0 high byte
if (count-- == 0)             //1ms * 1000 -> 1s
{
      count = 1000;             //reset counter
      TEST_LED = ! TEST_LED;    //work LED flash
}
}

//-----------------------------------------------

/* main program */
void main()
{
TMOD = 0x01;                   //set timer0 as mode1 (16-bit)
TL0 = T1MS;                   //initial timer0 low byte
TH0 = T1MS >> 8;             //initial timer0 high byte
TR0 = 1;                      //timer0 start running
ET0 = 1;                      //enable timer0 interrupt
EA = 1;                      //open global interrupt switch
count = 0;                   //initial counter

while (1);                   //loop
}

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