DASAR5, MENGENAL INTERUPT TIMER

/* ===================================================
Nama : Praktek5
Fungsi :-Mengenal manipulasi outport, shif register pass parameter.
    -Memanfaatkan sistem Timer untuk time delay
    -Memanfaat sistem interupt timer untuk time delay
====================================================*/

#include <at89x52.h>
#include <STRING.H>

int dly_stone;
int dir_stone;
unsigned char sts_arah;
//-----------------------------------------------

void InitTimer0(void)
{
TL0  = 0xFF;        // 10 ms
TH0  = 0xDB;
TMOD = 0x00;        // mode 1
TR0=1;                // timer-0 On
}
//------------------------------------------------

void delay2(int mul)
{
dly_stone = 0;
while(dly_stone< (50*mul));
}

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

void delay1(int mul)
{int i,j;
for(i=0; i< mul*1000;i++)
    for(j=0;j < mul*1000;j++);
}
//-----------------------------------------------------------------------------

void timer0 (void) interrupt 1 using 2
{
TL0=0xFF;
TH0=0xDB;
++dly_stone;
++dir_stone;
if (dir_stone >= 500)
    {if (sts_arah  == 0) sts_arah = 0x01;
    else sts_arah = 0;
    dir_stone = 0;
    }
}
//-----------------------------------------------

void main(void)
{unsigned char data1;
sts_arah = 0;
InitTimer0();
IE = 0x82;
data1 = 0x03;
for(;;)
    {
    P2 = data1 ^ 0xFF;
    delay1(1);
    if (sts_arah == 0x01)data1= data1 << 1;
    else data1= data1 >> 1;
    if (CY == 1)
          {if (sts_arah == 0x01)data1 |= 0x01;
           else  data1 |= 0x80;
    delay2(1);
    }
}