Initial

as68hc11/code/led.asm

@@ -0,0 +1,60 @@
+RAM    equ 0000h
+THIS   equ 0010h
+END    equ 0020h
+SCSR   equ 2Eh
+PORTB  equ 1004h      ; address of PORTB register
+  org RAM        
+  jmp BEGIN
+BEGIN:
+  ldab 01h            ; move 1 into register b
+  stab [PORTB]        ; light b0
+
+  ldab 03h            ; move 1 into register b
+  stab [PORTB]        ; light b0
+
+  bsr DELAY1K
+  ldab 00h            ; move 0 into register b
+  stab [PORTB]        ; turn off bo
+  bsr DELAY1K
+  jmp BEGIN
+
+;  ldaa [PORTB]        ; move contents of PORTB into register a
+;  ldab [PORTB]    ; 
+
+  rts
+DELAY10 equ *               ; 10ms delay @ 2.1 mhz
+  pshy                      ; save register y
+  ldy 0BB8h                 ; load loop counter into y register
+DELAY10LOOP equ *           ; loop counter sync address
+  dey                       ; decrement counter 
+  bne DELAY10LOOP           ; loop until zero in y
+  puly                      ; restore register y
+  rts                       ; return to caller
+DELAY1K equ *               ; 1000ms delay @ 2.1 mhz
+  pshy                      ; save register y
+  ldy 0Ah                   ; load 10d into register y
+DELAY1KLP equ *             ; loop counter sync address
+  bsr DELAY100              ; call 100 ms delay
+  dey                       ; decrement register y
+  bne DELAY1KLP             ; continue
+  puly                      ; restore register y
+  rts                       ; return to caller
+DELAY100 equ *              ; 100 ms @ 2.1 mhz
+  pshx                      ; save register x
+  ldx 07530h                ; load loop counter into register x
+DELAY100LP equ *            ; loop counter sync address
+  dex                       ; decrement register x
+  bne DELAY100LP            ; continue
+  pulx                      ; restore register x
+  rts                       ; return to caller
+
+
+
+
+
+
+
+
+
+
+