Datasheet

2. When the IVSEL bit in GICR is set, interrupt vectors will be moved to the start of the Boot Flash
section. The address of each interrupt vector will then be address in this table added to the start
address of the boot Flash section.
The next table 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.
Table 15-2. Reset and Interrupt Vectors Placement
BOOTRST
(1)
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
Note: 1. The Boot Reset Address is shown in table Boot Size Configuration in the Boot Loader
Parameters section. 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 ATmega32A
is:
address Labels Code Comments
$000 jmp RESET ; Reset Handler
$002 jmp EXT_INT0 ; IRQ0 Handler
$004 jmp EXT_INT1 ; IRQ1 Handler
$006 jmp EXT_INT2 ; IRQ2 Handler
$008 jmp TIM2_COMP ; Timer2 Compare
Handler
$00A jmp TIM2_OVF ; Timer2 Overflow
Handler
$00C jmp TIM1_CAPT ; Timer1 Capture
Handler
$00E jmp TIM1_COMPA ; Timer1 CompareA
Handler
$010 jmp TIM1_COMPB ; Timer1 CompareB
Handler
$012 jmp TIM1_OVF ; Timer1 Overflow
Handler
$014 jmp TIM0_COMP ; Timer0 Compare
Handler
$016 jmp TIM0_OVF ; Timer0 Overflow
Handler
Atmel ATmega32A [DATASHEET]
Atmel-8155I-ATmega32A_Datasheet_Complete-08/2016
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