AT90LS8535-4MC View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT90LS8535-4MC

8-Bit AVR® Microcontroller with 4K/8K Bytes In-System Programmable Flash

Atmel Corporation 

Reset Sources

1041H–11/01

AT90S/LS8535

Table 2. Reset and Interrupt Vectors (Continued)

Vector No. Program Address Source

13

$00C

UART, UDRE

14

$00D

UART, TX

15

$00E

ADC

16

$00F

EE_RDY

17

$010

ANA_COMP

Interrupt Definition

UART Data Register Empty

UART, Tx Complete

ADC Conversion Complete

EEPROM Ready

Analog Comparator

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 TIM2_COMP ; Timer2 Compare Handler

$004

rjmp TIM2_OVF

; Timer2 Overflow Handler

$005

rjmp TIM1_CAPT ; Timer1 Capture Handler

$006

rjmp TIM1_COMPA ; Timer1 CompareA Handler

$007

rjmp TIM1_COMPB ; Timer1 CompareB Handler

$008

rjmp TIM1_OVF

; Timer1 Overflow Handler

$009

rjmp TIM0_OVF

; Timer0 Overflow Handler

$00a

rjmp SPI_STC;

; SPI Transfer Complete Handler

$00b

rjmp UART_RXC

; UART RX Complete Handler

$00c

rjmp UART_DRE

; UDR Empty Handler

$00d

rjmp UART_TXC

; UART TX Complete Handler

$00e

Handler

rjmp ADC

; ADC Conversion Complete Interrupt

$00f

rjmp EE_RDY

; EEPROM Ready Handler

$010

rjmp ANA_COMP

; Analog Comparator Handler

$011 MAIN:

ldi

r16, high(RAMEND); Main program start

$012

out

SPH,r16

$013

ldi

r16, low(RAMEND) ;

$014

out

SPL,r16

$015

<instr> xxx

…

…

…

…

The AT90S8535 has three sources of reset:

• Power-on Reset. The MCU is reset when the supply voltage is below the Power-on

Reset threshold (VPOT).

• External Reset. The MCU is reset when a low level is present on the RESET pin for

more than 50 ns.

• Watchdog Reset. The MCU is reset when the Watchdog timer period expires and

the Watchdog is enabled.

During reset, all I/O registers are set to their initial values and the program starts execu-

tion from address $000. The instruction placed in address $000 must be an RJMP

(relative jump) instruction to the reset handling routine. If the program never enables an

interrupt source, the interrupt vectors are not used and regular program code can be

21

Share Link: