/*
Author Nikhil Arora
ele.nikhil@gmail
Learning SDCC
Timer program led blinked at p1.4 at every 250ms at p1.5 at 1sec and so on
crystal used 11.0592MHz
Program in main loop goes on parallelly
*/

#include <at89x051.h>

//Global Variables
unsigned char time1ms;
unsigned char time250ms;
unsigned char time1s;
unsigned char time1m;

//Function Prototypes
void delaysec(void);



void timer1_isr (void) interrupt 3 using 1
{
time1ms++;
if(time1ms==250)
{
time1ms=0;
time250ms++;
P1_4 = !P1_4;
if(time250ms==4)
{
time250ms=0;
time1s++;
P1_5 = !P1_5;
if(time1s==60)
{
time1s=0;
P1_6 = !P1_6;
time1m++;
if(time1m==60)
{
time1m=0;
P1_7 = !P1_7;
}
}
}
}
TH1 = 0xfc; //Delay
TL1 = 0x69; //Delay
}



void delaysec(void)
{
int i;
unsigned char j;
for(i=0;i<1500;i++)
{
for(j=0;j<100;j++){}
}
}


void main(void)
{

TMOD = 0x11; // Set to 16 bit timers
TH1 = 0xfc; // Delay
TL1 = 0x69; // Delay
ET1 = 1; // SET TIMER1 INTERRUPT

time1ms = 0; // Reset time
time250ms = 0; //
time1s = 0;
time1m = 0;

TR1 = 1; // Run Timer 1
EA = 1; // ENABLE GLOBAL INTERRUPT


while(1) // Main program blinking of LED at port3.7
{
P3_7 = !P3_7;
delaysec();
P3_7 = !P3_7;
delaysec();
}

}