Datasheet

© 2009 Microchip Technology Inc. DS39689F-page 99
PIC18F2221/2321/4221/4321 FAMILY
10.1 INTCON Registers
The INTCON registers are readable and writable
registers, which contain various enable, priority and
flag bits.
REGISTER 10-1: INTCON: INTERRUPT CONTROL REGISTER
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. User software should
ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt.
This feature allows for software polling.
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x
GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF
bit 7 bit 0
bit 7 GIE/GIEH: Global Interrupt Enable bit
When IPEN =
0:
1 = Enables all unmasked interrupts
0 = Disables all interrupts
When IPEN =
1:
1 = Enables all high-priority interrupts
0 = Disables all interrupts
bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit
When IPEN =
0:
1 = Enables all unmasked peripheral interrupts
0 = Disables all peripheral interrupts
When IPEN =
1:
1 = Enables all low-priority peripheral interrupts
0 = Disables all low-priority peripheral interrupts
bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit
1 = Enables the TMR0 overflow interrupt
0 = Disables the TMR0 overflow interrupt
bit 4 INT0IE: INT0 External Interrupt Enable bit
1 = Enables the INT0 external interrupt
0 = Disables the INT0 external interrupt
bit 3 RBIE: RB Port Change Interrupt Enable bit
1 = Enables the RB port change interrupt
0 = Disables the RB port change interrupt
bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit
1 = TMR0 register has overflowed (must be cleared in software)
0 = TMR0 register did not overflow
bit 1 INT0IF: INT0 External Interrupt Flag bit
1 = The INT0 external interrupt occurred (must be cleared in software)
0 = The INT0 external interrupt did not occur
bit 0 RBIF: RB Port Change Interrupt Flag bit
1 = At least one of the RB<7:4> pins changed state (must be cleared in software)
0 = None of the RB<7:4> pins have changed state
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown