Reset and interrupt handling – Rainbow Electronics ATmega103L User Manual
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ATmega603/103
24
Reset and Interrupt Handling
The ATmega603/103 provides 23 different interrupt sources. These interrupts and the separate reset vector each have a
separate program vector in the program memory space. All interrupts are assigned individual enable bits which must be set
(one) together with the I-bit in the status register in order to enable the interrupt.
The lowest addresses in the program memory space are automatically defined as the Reset and Interrupt vectors. The
complete list of vectors is shown in Table 5. The list also determines the priority levels of the different interrupts. The lower
the address the higher is the priority level. RESET has the highest priority, and next is INT0 - the External Interrupt Request
0 etc.
Table 5. Reset and Interrupt Vectors
Vector No.
Program Address
Source
Interrupt Definition
1
$0000
RESET
Hardware Pin, Power-on Reset and Watchdog Reset
2
$0002
INT0
External Interrupt Request 0
3
$0004
INT1
External Interrupt Request 1
4
$0006
INT2
External Interrupt Request 2
5
$0008
INT3
External Interrupt Request 3
6
$000A
INT4
External Interrupt Request 4
7
$000C
INT5
External Interrupt Request 5
8
$000E
INT6
External Interrupt Request 6
9
$0010
INT7
External Interrupt Request 7
10
$0012
TIMER2 COMP
Timer/Counter2 Compare Match
11
$0014
TIMER2 OVF
Timer/Counter2 Overflow
12
$0016
TIMER1 CAPT
Timer/Counter1 Capture Event
13
$0018
TIMER1 COMPA
Timer/Counter1 Compare Match A
14
$001A
TIMER1 COMPB
Timer/Counter1 Compare Match B
15
$001C
TIMER1 OVF
Timer/Counter1 Overflow
16
$001E
TIMER0 COMP
Timer/Counter0 Compare Match
17
$0020
TIMER0 OVF
Timer/Counter0 Overflow
18
$0022
SPI, STC
SPI Serial Transfer Complete
19
$0024
UART, RX
UART, Rx Complete
20
$0026
UART, UDRE
UART Data Register Empty
21
$0028
UART, TX
UART, Tx Complete
22
$002A
ADC
ADC Conversion Complete
23
$002C
EE READY
EEPROM Ready
24
$002E
ANALOG COMP
Analog Comparator