ozahmetdemir@gmail.com 2014

INTRODUCTION to

MICROCOMPUTERS in ESOGU

Example Question about 8085 Software Solved by AHMET ÖZDEMİR

Assume that three switches controls 8 LEDs a system

- 4 LEDs called Low Bank

- 4 LEDs called High Bank

Switches connected to PORT1 and LEDs connected to PORT2.

- SW0 controlls system ON/OFF

- If the system is ON;

SW1 controls (all lights on or off) Low Led Bank (4 LEDs)

SW2 controls (all lights on or off) High Led Bank (4 LEDs)

MNEMONICS SOLUTION INIT: START: READ: DISPLAY_0: DISPLAY_1: DISPLAY_2:

LXI MVI OUT IN ANI MOV ANI CPI JNZ JMP MOV CPI JNZ MVI OUT JMP CPI JNZ MVI OUT JMP MVI OUT JMP

SP,FFH 00H PORT2 PORT1 07H D,A 01H 00H DISPLAY_0 START A,D 02H DISPLAY_1 A,0FH PORT2 READ 05H DISPLAY_2 A,F0H PORT2 READ A,FFH PORT2 READ

START

Initialize StackPointer

Initialize each PORT for Blank

Read switches on PORT1

SW0 is ON

Light On

on Low Bank

No

Yes

SW1 is ON

No

No

Light On

on HighBank

Yes

Yes SW2 is ON

Both LEDs of Banks ON