Datasheet

62
8011O–AVR–07/10
ATmega164P/324P/644P
Notes: 1. When the BOOTRST Fuse is programmed, the device will jump to the Boot Loader address at
reset, see ”Memory Programming” on page 293.
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 9-2 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: 1. The Boot Reset Address is shown in Table 23-7 on page 288. 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
ATmega164P/324P/644P is:
28 $0036 SPM_READY Store Program Memory Ready
29 $0038 USART1_RX USART1 Rx Complete
30 $003A USART1_UDRE USART1 Data Register Empty
31 $003C USART1_TX USART1 Tx Complete
Table 9-2. Reset and Interrupt Vectors Placement
(1)
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
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
0x001A jmp TIM1_COMPA ; Timer1 CompareA
0x001C jmp TIM1_COMPB ; Timer1 CompareB
0x001E jmp TIM1_OVF ; Timer1 Overflow
0x0020 jmp TIM0_COMPA ; Timer0 CompareA
Table 9-1. Reset and Interrupt Vectors (Continued)
Vector
No.
Program
Address
(2)
Source Interrupt Definition