PIC16F684-ISL Microchip Technology Inc., PIC16F684-ISL Datasheet - Page 35

no-image

PIC16F684-ISL

Manufacturer Part Number
PIC16F684-ISL
Description
Manufacturer
Microchip Technology Inc.
Datasheets

Specifications of PIC16F684-ISL

Case
N/A
Notes
NEW
Date_code
11+
4.2.2
INTERRUPT-ON-CHANGE
Each of the PORTA pins is individually configurable as
an interrupt-on-change pin. Control bits IOCAx enable
or disable the interrupt function for each pin. Refer to
Register 4-4. The interrupt-on-change is disabled on a
Power-on Reset.
For enabled interrupt-on-change pins, the values are
compared with the old value latched on the last read of
PORTA. The ‘mismatch’ outputs of the last read are
OR’d together to set the PORTA Change Interrupt Flag
bit (RAIF) in the INTCON register (Register 2-3).
REGISTER 4-4:
IOCA – INTERRUPT-ON-CHANGE PORTA REGISTER (ADDRESS: 96h)
U-0
bit 7
bit 7-6
Unimplemented: Read as ‘0’
bit 5-0
IOCA<5:0>: Interrupt-on-change PORTA Control bit
1 = Interrupt-on-change enabled
0 = Interrupt-on-change disabled
Note 1: Global Interrupt Enable (GIE) must be enabled for individual interrupts to be
recognized.
2: IOCA<5:4> always reads ‘1’ in XT, HS and LP OSC modes.
Legend:
R = Readable bit
-n = Value at POR
 2004 Microchip Technology Inc.
This interrupt can wake the device from Sleep. The
user, in the Interrupt Service Routine, clears the
interrupt by:
a)
Any read or write of PORTA. This will end the
mismatch condition, then,
b)
Clear the flag bit RAIF.
A mismatch condition will continue to set flag bit RAIF.
Reading PORTA will end the mismatch condition and
allow flag bit RAIF to be cleared. The latch holding the
last read value is not affected by a MCLR nor BOD
Reset. After these resets, the RAIF flag will continue to
be set if a mismatch is present.
Note:
If a change on the I/O pin should occur
when the read operation is being executed
(start of the Q2 cycle), then the RAIF
interrupt flag may not get set.
U-0
R/W-0
R/W-0
R/W-0
IOCA5
IOCA4
IOCA3
W = Writable bit
U = Unimplemented bit, read as ‘0’
‘1’ = Bit is set
‘0’ = Bit is cleared
Preliminary
PIC16F684
R/W-0
R/W-0
R/W-0
IOCA2
IOCA1
IOCA0
bit 0
x = Bit is unknown
DS41202C-page 33

Related parts for PIC16F684-ISL