52
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P [DATASHEET]
8285E–AVR–02/2013
Table 12-2 on page 52 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 reg-
ular 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 sec-
tion or vice versa.
Note:
while “0” means programmed.
The most typical and general program setup for the Reset and Interrupt Vector Addresses in Atmel
ATmega165A/165PA is:
Address
Labels Code
Comments
0x0000
jmp
RESET
; Reset Handler
0x0002
jmp
EXT_INT0
; IRQ0 Handler
0x0004
jmp
PCINT0
; PCINT0 Handler
0x0006
jmp
PCINT1
; PCINT0 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_RXCn
; USART0 RX Complete Handler
0x001C
jmp
USART_DRE
; USART0,UDRn Empty Handler
0x001E
jmp
USART_TXCn
; USART0 TX Complete Handler
0x0020
jmp
USI_STRT
; USI Start Condition Handler
0x0022
jmp
USI_OVFL
; 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
;
0x002E
RESET: ldi
r16, high(RAMEND); Main program start
0x002F
out
SPH,r16
Set Stack Pointer to top of RAM
0x0030
ldi
r16, low(RAMEND)
0x0031
out
SPL,r16
0x0032
sei
; Enable interrupts
0x0033
<instr>
xxx
...
Table 12-2.
Reset and interrupt vectors placement
(1).
BOOTRST
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