76
8271D–AVR–05/11
ATmega48A/PA/88A/PA/168A/PA/328/P
• Bit 0 – PCIF0: Pin Change Interrupt Flag 0
When a logic change on any PCINT[7:0] pin triggers an interrupt request, PCIF0 becomes set
(one). If the I-bit in SREG and the PCIE0 bit in PCICR are set (one), the MCU will jump to the
corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alter-
natively, the flag can be cleared by writing a logical one to it.
13.2.6
PCMSK2 – Pin Change Mask Register 2
• Bit 7:0 – PCINT[23:16]: Pin Change Enable Mask 23...16
Each PCINT[23:16]-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT[23:16] is set and the PCIE2 bit in PCICR is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT[23:16] is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
13.2.7
PCMSK1 – Pin Change Mask Register 1
• Bit 7 – Reserved
This bit is an unused bit in the ATmega48A/PA/88A/PA/168A/PA/328/P, and will always read as
zero.
• Bit 6:0 – PCINT[14:8]: Pin Change Enable Mask 14...8
Each PCINT[14:8]-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT[14:8] is set and the PCIE1 bit in PCICR is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT[14:8] is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
13.2.8
PCMSK0 – Pin Change Mask Register 0
• Bit 7:0 – PCINT[7:0]: Pin Change Enable Mask 7...0
Each PCINT[7:0] bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT[7:0] is set and the PCIE0 bit in PCICR is set, pin change interrupt is enabled on the
corresponding I/O pin. If PCINT[7:0] is cleared, pin change interrupt on the corresponding I/O
pin is disabled.
Bit
7
6
5
4
3
2
1
0
PCINT23
PCINT22
PCINT21
PCINT20
PCINT19
PCINT18
PCINT17
PCINT16
PCMSK2
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
–
PCINT14
PCINT13
PCINT12
PCINT11
PCINT10
PCINT9
PCINT8
PCMSK1
Read/Write
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
PCINT7
PCINT6
PCINT5
PCINT4
PCINT3
PCINT2
PCINT1
PCINT0
PCMSK0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0