while(1) {
pause (duration);
turn pin on;
pause (duration);
turn pin off
}

byte duration = 255;

int main() {
high(pin);
high(pin);
pause(duration);
low(pin);
duration—;
pause(duration);
}

int microsec = CLKFREQ/1000000; // divide the clock rate by a million to get ticks per microsecond
int highClocks = microsec * 10; // highClocks will be 10 microseconds, or 800 clocks at 80mhz
int lowClocks = microsec * 90;

DIRA |= (1<<15); // set pin 15 as an output by enabling bit 15 in the DIRA register

while( true ) // loop forever
{
OUTA |= (1<<15); // Enable bit 15 in the output register (same as high(15), but faster)
waitcnt( CNT + highClocks ); // add highClocks to the current clock, wait for the clock to reach that value

OUTA &= ~(1<<15); // Clear bit 15 in the output register (same as low(15) but faster)
waitcnt( CNT + lowClocks ); // add lowClocks to the current clock, wait for the clock to reach that value
}