Datasheet
70
8011O–AVR–07/10
ATmega164P/324P/644P
• Bit 1 – PCIF1: Pin Change Interrupt Flag 1
When a logic change on any PCINT15..8 pin triggers an interrupt request, PCIF1 becomes set
(one). If the I-bit in SREG and the PCIE1 bit in EIMSK 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.
• Bit 0 – PCIF0: Pin Change Interrupt Flag 0
When a logic change on any PCINT7..0 pin triggers an interrupt request, PCIF0 becomes set
(one). If the I-bit in SREG and the PCIE0 bit in EIMSK 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.
10.2.6 PCMSK3 – Pin Change Mask Register 3
• Bit 7:0 – PCINT31:24: Pin Change Enable Mask 31:24
Each PCINT31:24-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT31:24 is set and the PCIE2 bit in PCICR is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT31..24 is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
10.2.7 PCMSK2 – Pin Change Mask Register 2
• Bit 7:0 – PCINT23:16: Pin Change Enable Mask 23..16
Each PCINT23:16-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT23:16 is set and the PCIE2 bit in PCICR is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT23..16 is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
10.2.8 PCMSK1 – Pin Change Mask Register 1
• Bit 7:0 – PCINT15:8: Pin Change Enable Mask 15..8
Each PCINT15:8-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT15:8 is set and the PCIE1 bit in EIMSK is set, pin change interrupt is enabled on the
corresponding I/O pin. If PCINT15:8 is cleared, pin change interrupt on the corresponding I/O
pin is disabled.
Bit 76543210
(0x73)
PCINT31 PCINT30 PCINT29 PCINT28 PCINT27 PCINT26 PCINT25 PCINT24 PCMSK3
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 76543210
(0x6D)
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 76543210
(0x6C)
PCINT15 PCINT14 PCINT13 PCINT12 PCINT11 PCINT10 PCINT9 PCINT8 PCMSK1
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