#include <C8051F340.h>

void configTimer (void);
void configInterruption (void);
void reloadTimer (void);
void switch_0 (void) __interrupt 0;
void switch_1(void) __interrupt 2;
void RSI_Timer0 (void) __interrupt 1;

char overflowCounter = 0;
char threshold = 128;

int main (void) {

	configTimer();

	configInterruption();

	TR0 = 1;

	while (1) {

		if (overflowCounter<=threshold) {
			P2_2=1;
		} else {
			P2_2=0;
		}
	}
}

void RSI_Timer0 (void) __interrupt 1 {
	overflowCounter++;
}

void switch_0 (void) __interrupt 0 {
	threshold++;
}

void switch_1 (void) __interrupt 2 {
	threshold--;
}

void configTimer (void) {
	P2MDOUT = 0x0C;
	P0SKIP = 0xFF;
	P1SKIP = 0xFF;
	XBR1 = 0X70;
	OSCICN = 0x83;
	PCA0MD &= 0xBF;
	PCA0MD = 0x00;

	reloadTimer ();
	TMOD=0x01;
}

void configInterruption (void) {
	IE=0x87;
	IT01CF=0xC1;
}

void reloadTimer (void) {
	TH0=0xFC;
	TL0=0xFC;
}