54
8023F–AVR–07/09
ATmega325P/3250P
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 ATmega3250P and ATmega6450P.
Table 11-2 shows reset and Interrupt Vectors placement for the various combinations of
BOOTRST and 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.
Note:
means unprogrammed while “0” means programmed.
The most typical and general program setup for the Reset and Interrupt Vector Addresses in
ATmega325P/3250P is:
Table 11-2.
Reset and Interrupt Vectors Placemen
tBOOTRST
IVSEL
Reset Address
Interrupt Vectors Start Address
1
0
0x0000
0x0002
1
0x0000
Boot Reset Address + 0x0002
0
Boot Reset Address
0x0002
0
1
Boot Reset Address
Boot Reset Address + 0x0002
Address
Labels
Code
Comments
0x0000
jmp
RESET
; Reset Handler
0x0002
jmp
EXT_INT0
; IRQ0 Handler
0x0004
jmp
PCINT0
; PCINT0 Handler
0x0006
jmp
PCINT1
; PCINT1 Handler
0x0008
jmp
TIM2_COMP
; Timer2 Compare Handler
0x000A
jmp
TIM2_OVF
; Timer2 Overflow Handler
0x000C
jmp
TIM1_CAPT
; Timer1 Capture Handler
0x000E
jmp
TIM1_COMPA
; Timer1 CompareA Handler
0x0010
jmp
TIM1_COMPB
; Timer1 CompareB Handler
0x0012
jmp
TIM1_OVF
; Timer1 Overflow Handler
0x0014
jmp
TIM0_COMP
; Timer0 Compare Handler
0x0016
jmp
TIM0_OVF
; Timer0 Overflow Handler
0X0018
jmp
SPI_STC
; SPI Transfer Complete Handler
0x001A
jmp
USART_RXC
; USART0 RX Complete Handler
0x001C
jmp
USART_UDRE
; USART0,UDR0 Empty Handler
0x001E
jmp
USART_TXC
; USART0 TX Complete Handler
0x0020
jmp
USI_STRT
; USI Start Condition Handler
0x0022
jmp
USI_OVF
; USI Overflow Handler
0x0024
jmp
ANA_COMP
; Analog Comparator Handler
0x0026
jmp
ADC
; ADC Conversion Complete Handler
0x0028
jmp
EE_RDY
; EEPROM Ready Handler
0x002A
jmp
SPM_RDY
; SPM Ready Handler
0x002C
jmp
NOT_USED
; RESERVED
0x002E
jmp
PCINT2
; PCINT2 Handler
0x0030
jmp
PCINT3
; PCINT3 Handler
;