;
; ==================================================
;
;   LEDS2P.asm      Blinking Led File  
;                                 
;   Version:        1.0   Released 10/10/2002
;   Author:         Gary Karnes 
;   Compiler:       As12
;   Platform:       Axiom CML12S
;   Purpose:        Blink a Led  
; ==================================================
;  Hardware
;   Four Led's with cathode's connected by
;   four 1k resistor to ground
;   Led anode's connected to Port K bits 0 thru 3.
;
; Blinking Led's
; 
;
PORTK:     equ  $32       ; port K data
DDRK:      equ  $33       ; port K direction
LED1:      equ  $01       ; LED 1 select
LED2:      equ  $02       ; LED 2 select
LED3:      equ  $04       ; LED 3 select
LED4:      equ  $08       ; LED 4 select

           org $1000


; Setup port K
MAIN:
           movb  #$0F,DDRK   ; bits 0-3 as outputs
           bclr  PORTK,LED1+LED2+LED3+LED4   ; all bits low
           jsr   DELAY
;
; LED one

           bset  PORTK,LED1    ; LED one On
           jsr   DELAY 
           bclr  PORTK,LED1    ; LED one Off
           jsr   DELAY

; LED two 

           bset  PORTK,LED2    ; LED two On
           jsr   DELAY 
           bclr  PORTK,LED2    ; LED two Off
           jsr   DELAY


; LED three 

           bset  PORTK,LED3    ; LED three On
           jsr   DELAY 
           bclr  PORTK,LED3    ; LED three Off
           jsr   DELAY


; LED four 
     
           bset  PORTK,LED4    ; LED four On
           jsr   DELAY 
           bclr  PORTK,LED4    ; LED four Off
           jsr   DELAY
 

           jmp  MAIN            ; start over
;     
; Delay subroutine 
DELAY:
           ldab #$0F
DELAYL1:       
           ldx  #$ffff 
DELAYL:     
           dbne  X,DELAYL
           
           dbne  B,DELAYL1
           rts 

			end