Data Sheet

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8161D–AVR–10/09

ATmega48PA/88PA/168PA/328P

Notes: 1. When the BOOTRST Fuse is programmed, the device will jump to the Boot Loader address at reset, see ”Boot Loader Sup-

port – Read-While-Write Self-Programming, ATmega88PA, ATmega168PA and ATmega328P” on page 277.

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.

Table 11-7 on page 66 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: 1. The Boot Reset Address is shown in Table 26-7 on page 289. 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

ATmega328P is:

Address Labels Code Comments

0x0000 jmp RESET ; Reset Handler

0x0002 jmp EXT_INT0 ; IRQ0 Handler

0x0004 jmp EXT_INT1 ; IRQ1 Handler

0x0006 jmp PCINT0 ; PCINT0 Handler

0x0008 jmp PCINT1 ; PCINT1 Handler

0x000A jmp PCINT2 ; PCINT2 Handler

0x000C jmp WDT ; Watchdog Timer Handler

0x000E jmp TIM2_COMPA ; Timer2 Compare A Handler

0x0010 jmp TIM2_COMPB ; Timer2 Compare B Handler

0x0012 jmp TIM2_OVF ; Timer2 Overflow Handler

0x0014 jmp TIM1_CAPT ; Timer1 Capture Handler

0x0016 jmp TIM1_COMPA ; Timer1 Compare A Handler

0x0018 jmp TIM1_COMPB ; Timer1 Compare B Handler

0x001A jmp TIM1_OVF ; Timer1 Overflow Handler

0x001C jmp TIM0_COMPA ; Timer0 Compare A Handler

0x001E jmp TIM0_COMPB ; Timer0 Compare B Handler

23 0x002C EE READY EEPROM Ready

24 0x002E ANALOG COMP Analog Comparator

25 0x0030 TWI 2-wire Serial Interface

26 0x0032 SPM READY Store Program Memory Ready

Table 11-6. Reset and Interrupt Vectors in ATmega328P (Continued)

VectorNo.

Program

Address

(2)

Source Interrupt Definition

Table 11-7. Reset and Interrupt Vectors Placement in ATmega328P

(1)

BOOTRST IVSEL Reset Address Interrupt Vectors Start Address

1 0 0x000 0x002

1 1 0x000 Boot Reset Address + 0x0002

0 0 Boot Reset Address 0x002

0 1 Boot Reset Address Boot Reset Address + 0x0002