Atmel AVR STK500 - Section 9 Example Applications; 9.1 Using LEDs and Switches

AVR STK500 User Guide 9-1
Rev. 1925C–AVR–3/03
Section 9
Example Applications
9.1 Using LEDs and
Switches
Connect PORTB to LEDS and PORTD to SWITCHES.
LEDs will operate differently depending on what switch is pressed.
Tip: Copy the code from this document into AVR Studio.
;***** STK500 LEDS and SWITCH demonstration
.include “8515def.inc”
.def Temp =r16 ; Temporary register
.def Delay =r17 ; Delay variable 1
.def Delay2 =r18 ; Delay variable 2
;***** Initialization
RESET:
ser Temp
out DDRB,Temp ; Set PORTB to output
;**** Test input/output
LOOP:
out PORTB,temp ; Update LEDS
sbis PIND,0x00 ; If (Port D, pin0 == 0)
inc Temp ; then count LEDS one down
sbis PIND,0x01 ; If (Port D, pin1 == 0)