chap9.asm

Motorola 6812芯片开发的接口程序。

; Chapter 9 6812 assembly language programs
; Jonathan W. Valvano
; This software accompanies the book,
; Real Time Embedded Systems published by Brooks Cole
;


;  Program 9.11. Method for calling functions in extended PROM.
*****regular******
    org $C000
main lds #$C00
* call func2 in page1
    call fun2,1
* call func3 in page2
    call fun3,2
* call func1 in page1
    call fun1,1


global

     rts
     org $FFFE
     dc.w main

******page 1******
      lbra func1
      lbra func2
      lbra func3
func1 
* call func2 in page 2
      call fun3,2
      rtc
func2
* call global function
      jsr  global 
      rtc
func3
* call func2 same page
      call fun2,1
      rtc

******page 2******
      lbra func1
      lbra func2
      lbra func3
func1 
      rtc
func2
* call a local function
      bsr  local
      rtc
func3
* call func2 same page
      call fun2,2
      rtc
local
      rts