when specified interrupt occurs.
ON interrupt label
interrupt INT0, INT1,
SERIAL, TIMER0 ,TIMER1 or TIMER2.
Chip specific interrupts can be found under microprocessor support.
Label The label to jump to if the interrupt occurs.
NOSAVE When you specify NOSAVE, no registers are saved and restored in
the interrupt routine. So when you use this option be sure to save and
restore used registers.
You must return from the interrupt routine with the RETURN statement.
You may have only one RETURN statement in your interrupt routine because
the compiler restores the registers and generates a RETI instruction when
it encounters a RETURN statement in the ISR.
You can't use TIMER1
when you are using SERIAL routines such as PRINT
because TIMER1 is used as a BAUDRATE generator.
When you use the INT0
or INT1 interrupt you can specify on which condition the interrupt must
You can use the Set/Reset
statement in combination with the TCON-register for this purpose.
SET TCON.0 : trigger
INT0 by falling edge.
RESET TCON.0 : trigger INT0 by low level.
SET TCON.2 : trigger INT1 by falling edge.
RESET TCON.2 : trigger INT1 by low level.
See Hardware for more
ENABLE INT0 'enable the interrupt
ON INT0 Label2 nosave 'jump
to label2 on INT0
DO 'endless loop
PRINT " An hardware interrupt occurred!"