PIC12F635/PIC16F636/639
2.2.2.3 INTCON Register
The INTCON register is a readable and writable
register which contains the various enable and flag bits
for TMR0 register overflow, PORTA change and
external RA2/INT pin interrupts.
Note:
Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the Global
Interrupt Enable bit, GIE (INTCON<7>).
User software should ensure the appropri-
ate interrupt flag bits are clear prior to
enabling an interrupt.
REGISTER 2-3:
INTCON – INTERRUPT CONTROL REGISTER (ADDRESS: 0Bh OR 8Bh)
R/W-0
GIE
R/W-0
PEIE
R/W-0
T0IE
R/W-0
INTE
R/W-0
RAIE(1)
R/W-0
T0IF(2)
R/W-0
INTF
R/W-0
RAIF(3)
bit 7
bit 0
bit 7
GIE: Global Interrupt Enable bit
1 = Enables all unmasked interrupts
0 = Disables all interrupts
bit 6
PEIE: Peripheral Interrupt Enable bit
1 = Enables all unmasked peripheral interrupts
0 = Disables all peripheral interrupts
bit 5
T0IE: TMR0 Overflow Interrupt Enable bit
1 = Enables the TMR0 interrupt
0 = Disables the TMR0 interrupt
bit 4
INTE: RA2/INT External Interrupt Enable bit
1 = Enables the RA2/INT external interrupt
0 = Disables the RA2/INT external interrupt
bit 3
RAIE: PORTA Change Interrupt Enable bit(1)
1 = Enables the PORTA change interrupt
0 = Disables the PORTA change interrupt
bit 2
T0IF: TMR0 Overflow Interrupt Flag bit(2)
1 = TMR0 register has overflowed (must be cleared in software)
0 = TMR0 register did not overflow
bit 1
INTF: RA2/INT External Interrupt Flag bit
1 = The RA2/INT external interrupt occurred (must be cleared in software)
0 = The RA2/INT external interrupt did not occur
bit 0
RAIF: PORTA Change Interrupt Flag bit(3)
1 = When at least one of the PORTA <5:0> pins changed state (must be cleared in software)
0 = None of the PORTA <5:0> pins have changed state
Note 1: IOCA register must also be enabled.
2: T0IF bit is set when Timer0 rolls over. Timer0 is unchanged on Reset and should
be initialized before clearing the T0IF bit.
3: MCLR and WDT Reset do not affect the previous value data latch. The RAIF bit will
be cleared upon Reset but will set again if the mismatch exists.
Legend:
R = Readable bit
- n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
DS41232B-page 22
Preliminary
© 2005 Microchip Technology Inc.