EER-018
Introduction to Digital Computers
 Lecture 25

More 6805 Program Examples

Review 6805 Branch and Jump Instructions

Example:

delay: lda #$1F
       sta $C1
loop1: lda #$1F
       sta $C2
loop2: dec $C2
       bne loop2  ; count down inner loop counter
       dec $C1
       bne loop1  ; count down outer loop counter

Memory-mapped I/O

PortA - location $0000
PortB - location $0001

DDRA - location $0004
DDRB - location $0005

Programs using I/O