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Reset and interrupt handling – Rainbow Electronics AT90S2313 User Manual

Page 18

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AT90S2313

0839I–AVR–06/02

Reset and Interrupt
Handling

The AT90S2313 provides 10 different interrupt sources. These interrupts and the sepa-
rate Reset Vector each have a separate Program Vector in the program memory space.
All the interrupts are assigned individual enable bits that 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 2. The list
also determines the priority levels of the different interrupts. The lower the address, the
higher the priority level. RESET has the highest priority, and next is INT0 (the External
Interrupt Request 0), etc.

The most typical and general program setup for the Reset and Interrupt Vector
addresses are:

Address Labels

Code

Comments

$000

rjmp RESET

; Reset Handler

$001

rjmp EXT_INT0

; IRQ0 Handler

$002

rjmp EXT_INT1

; IRQ1 Handler

$003

rjmp TIM_CAPT1

; Timer1 Capture Handler

$004

rjmp TIM_COMP1

; Timer1 Compare Handler

$005

rjmp TIM_OVF1

; Timer1 Overflow Handler

$006

rjmp TIM_OVF0

; Timer0 Overflow Handler

$007

rjmp UART_RXC

; UART RX Complete Handler

$008

rjmp UART_DRE

; UDR Empty Handler

$009

rjmp UART_TXC

; UART TX Complete Handler

$00a

rjmp ANA_COMP

; Analog Comparator Handler

;

$00b

MAIN:

ldi r16,low(RAMEND); Main program start

$00c

out SPL,r16

$00d

xxx

Table 2. Reset and Interrupt Vectors

Vector No.

Program Address

Source

Interrupt Definition

1

$000

RESET

Hardware Pin, Power-on Reset and
Watchdog Reset

2

$001

INT0

External Interrupt Request 0

3

$002

INT1

External Interrupt Request 1

4

$003

TIMER1 CAPT1

Timer/Counter1 Capture Event

5

$004

TIMER1 COMP1

Timer/Counter1 Compare Match

6

$005

TIMER1 OVF1

Timer/Counter1 Overflow

7

$006

TIMER0 OVF0

Timer/Counter0 Overflow

8

$007

UART, RX

UART, RX Complete

9

$008

UART, UDRE

UART Data Register Empty

10

$009

UART, TX

UART, TX Complete

11

$00A

ANA_COMP

Analog Comparator