Datasheet
Vector No Program Address
(2)
Source Interrupts definition
21 0x0028 USART_RX USART Rx Complete
22 0x002A USART_UDRE USART Data Register Empty
23 0x002C USART_TX USART Tx Complete
24 0x002E ANALOG_COMP Analog Comparator
25 0x0030 ADC ADC Conversion Complete
26 0x0032 EE_READY EEPROM Ready
27 0x0034 TWI TWI Transfer complete
28 0x0036 SPM_READY Store Program Memory Ready
29 0x0038 USART1_RX USART1 Rx Complete
30 0x003A USART1_UDRE USART1, Data Register Empty
31 0x003C USART1_TX USART1, Tx Complete
Note:
1. When the BOOTRST Fuse is programmed, the device will jump to the Boot Loader address at
reset, see Memory programming
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.
The table below shows reset and Interrupt Vectors placement for the various combinations of BOOTRST
and MCUCR.IVSEL settings. If the program never enables an interrupt source, the Interrupt Vectors are
not used, and regular program code can be placed at these locations. This is also the case if the Reset
Vector is in the Application section while the Interrupt Vectors are in the Boot section or vice versa.
Table 13-2. Reset and Interrupt Vectors placement
BOOTRST IVSEL Reset Address Interrupt Vectors Start Address
1 0 0x0000 0x0002
1 1 0x0000 Boot Reset Address + 0x0002
0 0 Boot Reset Address 0x0002
0 1 Boot Reset Address Boot Reset Address + 0x0002
Note: The Boot Reset Address is shown in Table Boot size configuration in Boot Loader Parameters.
For the BOOTRST Fuse “1” means unprogrammed while “0” means programmed.
Address Labels Code Comments
0x0000 jmp RESET ; Reset
0x0002 jmp INT0 ; IRQ0
0x0004 jmp INT1 ; IRQ1
0x0006 jmp INT2 ; IRQ2
0x0008 jmp PCINT0 ; PCINT0
0x000A jmp PCINT1 ; PCINT1
0x000C jmp PCINT2 ; PCINT2
0x000E jmp PCINT3 ; PCINT3
0x0010 jmp WDT ; Watchdog Timeout
0x0012 jmp TIM2_COMPA ; Timer2 CompareA
0x0014 jmp TIM2_COMPB ; Timer2 CompareB
0x0016 jmp TIM2_OVF ; Timer2 Overflow
0x0018 jmp TIM1_CAPT ; Timer1 Capture
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
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