STC12C5A-Timer

stc12c5a-timer.c

/* define constants */
#define FOSC 11059000L              // 11.059 MHz

// #define T1MS (65536-FOSC/1000)      //1ms timer calculation method in 1T mode
#define T1MS_H    0xD4
#define T1MS_L    0xCC

/* define variables */
WORD count = 1000;                         //1000 times counter
WORD timestamp = 0;

/* Timer0 interrupt routine */
void tm0_isr() interrupt 1 using 1
{
    TL0 = T1MS_L;                   //reload timer0 low byte
    TH0 = T1MS_H;                   //reload timer0 high byte
    if (count-- == 0)               //1ms * 1000 -> 1s
    {
        count = 1000;               //reset counter
        ++timestamp;
    }
}
void Timer0Init(void)		//1毫秒@11.0592MHz
{
	AUXR |= 0x80;		//定时器时钟1T模式
	TMOD &= 0xF0;		//设置定时器模式
	TMOD |= 0x01;		//设置定时器模式
    TL0 = T1MS_L;
    TH0 = T1MS_H;
	TF0 = 0;		//清除TF0标志
	TR0 = 1;		//定时器0开始计时
	ET0 = 1;                        //enable timer0 interrupt
}

// enable interrupt in main()
// EA = 1;                         //open global interrupt switch