Datasheet

Table Of Contents
50
2570N–AVR–05/11
ATmega325/3250/645/6450
Table 12-2 on page 50 shows reset and Interrupt Vectors placement for the various combina-
tions 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: The Boot Reset Address is shown in Table 26-6 on page 262. For the BOOTRST Fuse “1” means
unprogrammed while “0” means programmed.
The most typical and general program setup for the Reset and Interrupt Vector Addresses in
Atmel ATmega325/3250/645/6450 is:
Table 12-2. Reset and Interrupt Vectors Placement
(Note:)
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
Addre
ss
Label
s
Code Comments
0x000
0
jmp RESET ; Reset Handler
0x000
2
jmp EXT_INT0 ; IRQ0 Handler
0x000
4
jmp PCINT0 ; PCINT0 Handler
0x000
6
jmp PCINT1 ; PCINT1 Handler
0x000
8
jmp TIM2_COMP ; Timer2 Compare Handler
0x000
A
jmp TIM2_OVF ; Timer2 Overflow Handler
0x000
C
jmp TIM1_CAPT ; Timer1 Capture Handler
0x000
E
jmp TIM1_COMPA ; Timer1 CompareA Handler
0x001
0
jmp TIM1_COMPB ; Timer1 CompareB Handler
0x001
2
jmp TIM1_OVF ; Timer1 Overflow Handler
0x001
4
jmp TIM0_COMP ; Timer0 Compare Handler
0x001
6
jmp TIM0_OVF ; Timer0 Overflow Handler
0X001
8
jmp SPI_STC ; SPI Transfer Complete Handler
0x001
A
jmp USART_RXC ; USART RX Complete Handler
0x001
C
jmp USART_UDRE ; USART,UDR Empty Handler
0x001
E
jmp USART_TXC ; USART TX Complete Handler
0x002
0
jmp USI_STRT ; USI Start Condition Handler