ATMEGA649_14 Datasheet, PDF (57/392 Pages) ATMEL Corporation – High Endurance Non-volatile Memory Segments

ATmega329/3290/649/6490
• Bit 4 – 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.
12.2.4
• Bit 0 – INTF0: External Interrupt Flag 0
When an edge or logic change on the INT0 pin triggers an interrupt request, INTF0 becomes set
(one). If the I-bit in SREG and the INT0 bit in EIMSK are set (one), the MCU will jump to the cor-
responding Interrupt Vector. The flag is cleared when the interrupt routine is executed.
Alternatively, the flag can be cleared by writing a logical one to it. This flag is always cleared
when INT0 is configured as a level interrupt.
PCMSK3 – Pin Change Mask Register 3⁽¹⁾
Bit
7
6
5
4
3
2
1
0
(0x73)
–
PCINT30 PCINT29 PCINT28 PCINT27 PCINT26 PCINT25 PCINT24 PCMSK3
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
12.2.5
• Bit 6:0 – PCINT30..24: Pin Change Enable Mask 30..24
Each PCINT30..24-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT30..24 is set and the PCIE3 bit in EIMSK is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT30..24 is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
PCMSK2 – Pin Change Mask Register 2⁽¹⁾
Bit
(0x6D)
Read/Write
Initial
Value
7
PCINT23
R/W
0
6
PCINT22
R/W
0
5
PCINT21
R/W
0
4
PCINT20
R/W
0
3
PCINT19
R/W
0
2
PCINT18
R/W
0
1
PCINT17
R/W
0
0
PCINT16
R/W
0
PCMSK2
• 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 EIMSK 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.
Note: 1. PCMSK3 and PCMSK2 are only present in ATmega3290/6490.
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