sfr at 0x80 P0;
sfr at 0x90 P1;
sfr at 0xA0 P2;

#define PERCFG	SFR(0xF1)
#define ADCCFG	SFR(0xF2)
#define P0SEL	SFR(0xF3)
#define P1SEL	SFR(0xF4)
#define P2SEL	SFR(0xF5)

sfr at 0xFD P0DIR;
sfr at 0xFE P1DIR;
sfr at 0xFE P2DIR;
sfr at 0x8F P0INP;
sfr at 0xF6 P1INP;
sfr at 0xF7 P2INP;

#define P0IFG	SFR(0x89)
#define P1IFG	SFR(0x8A)
#define P2IFG	SFR(0x8B)

#define nop()	_asm \
		nop \
		_endasm;

main ()
{
	int	i, j;
	/* Set p1_1 to output */
	P1DIR = 0x02;
	P1INP = 0x00;
	P2INP = 0x00;
	for (;;) {
		P1 = 0xff;
		for (j = 0; j < 100; j++)
			for (i = 0; i < 1000; i++)
				nop();
		P1 = 0xfd;
		for (j = 0; j < 100; j++)
			for (i = 0; i < 1000; i++)
				nop();
	}
}