49
2570N–AVR–05/11
ATmega325/3250/645/6450
12. Interrupts
This section describes the specifics of the interrupt handling as performed in Atmel
ATmega325/3250/645/6450. For a general explanation of the AVR interrupt handling, refer to
12.1
Interrupt Vectors in Atmel ATmega325/3250/645/6450
Note:
1. When the BOOTRST Fuse is programmed, the device will jump to the Boot Loader address at reset, see
“Boot Loader Sup-2. When the IVSEL bit in MCUCR is set, Interrupt Vectors will be moved to the start of the Boot Flash Section. The address of
each Interrupt Vector will then be the address in this table added to the start address of the Boot Flash Section.
3. PCINT2 and PCINT3 are only present in ATmega3250 and ATmega6450.
Table 12-1.
Reset and Interrupt Vectors
Vector
No.
Program
Source
Interrupt Definition
1
RESET
External Pin, Power-on Reset, Brown-out Reset,
Watchdog Reset, and JTAG AVR Reset
2
0x0002
INT0
External Interrupt Request 0
3
0x0004
PCINT0
Pin Change Interrupt Request 0
4
0x0006
PCINT1
Pin Change Interrupt Request 1
5
0x0008
TIMER2 COMP
Timer/Counter2 Compare Match
6
0x000A
TIMER2 OVF
Timer/Counter2 Overflow
7
0x000C
TIMER1 CAPT
Timer/Counter1 Capture Event
8
0x000E
TIMER1 COMPA
Timer/Counter1 Compare Match A
9
0x0010
TIMER1 COMPB
Timer/Counter1 Compare Match B
10
0x0012
TIMER1 OVF
Timer/Counter1 Overflow
11
0x0014
TIMER0 COMP
Timer/Counter0 Compare Match
12
0x0016
TIMER0 OVF
Timer/Counter0 Overflow
13
0x0018
SPI, STC
SPI Serial Transfer Complete
14
0x001A
USART, RX
USART, Rx Complete
15
0x001C
USART, UDRE
USART Data Register Empty
16
0x001E
USART, TX
USART, Tx Complete
17
0x0020
USI START
USI Start Condition
18
0x0022
USI OVERFLOW
USI Overflow
19
0x0024
ANALOG COMP
Analog Comparator
20
0x0026
ADC
ADC Conversion Complete
21
0x0028
EE READY
EEPROM Ready
22
0x002A
SPM READY
Store Program Memory Ready
23
0x002C
NOT_USED
RESERVED
0x002E
PCINT2
Pin Change Interrupt Request 2
0x0030
PCINT3
Pin Change Interrupt Request 3