
69
8272E–AVR–04/2013
ATmega164A/PA/324A/PA/644A/PA/1284/P
is executed. Alternatively, the flag can be cleared by writing a logical one to it. These flags are
always cleared when INT2:0 are configured as level interrupt. Note that when entering sleep
mode with the INT2:0 interrupts disabled, the input buffers on these pins will be disabled. This
may cause a logic change in internal signals which will set the INTF2:0 flags. See
”Digital Input13.2.4
PCICR – Pin Change Interrupt Control Register
Bit 3 – PCIE3: Pin Change Interrupt Enable 3
When the PCIE3 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin
change interrupt 3 is enabled. Any change on any enabled PCINT31:24 pin will cause an inter-
rupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI3
Interrupt Vector. PCINT31:24 pins are enabled individually by the PCMSK3 Register.
Bit 2 – PCIE2: Pin Change Interrupt Enable 2
When the PCIE2 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin
change interrupt 2 is enabled. Any change on any enabled PCINT23:16 pin will cause an inter-
rupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI2
Interrupt Vector. PCINT23:16 pins are enabled individually by the PCMSK2 Register.
Bit 1 – PCIE1: Pin Change Interrupt Enable 1
When the PCIE1 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin
change interrupt 1 is enabled. Any change on any enabled PCINT15:8 pin will cause an inter-
rupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI1
Interrupt Vector. PCINT15:8 pins are enabled individually by the PCMSK1 Register.
Bit 0 – PCIE0: Pin Change Interrupt Enable 0
When the PCIE0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin
change interrupt 0 is enabled. Any change on any enabled PCINT7:.0 pin will cause an interrupt.
The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI0 Interrupt
Vector. PCINT7:0 pins are enabled individually by the PCMSK0 Register.
13.2.5
PCIFR – Pin Change Interrupt Flag Register
Bit 3– PCIF3: Pin Change Interrupt Flag 3
When a logic change on any PCINT31:24 pin triggers an interrupt request, PCIF3 becomes set
(one). If the I-bit in SREG and the PCIE3 bit in PCICR are set (one), the MCU will jump to the
natively, the flag can be cleared by writing a logical one to it.
Bit
7
6543
210
–
PCIE3
PCIE2
PCIE1
PCIE0
PCICR
Read/Write
RRRR
R/W
Initial Value
0
0000
000
Bit
7
6543
210
–
PCIF3
PCIF2
PCIF1
PCIF0
PCIFR
Read/Write
RRRR
R/W
Initial Value
0
0000
000