prog13.asm

包括了各种常用的8051单片机的程序

;  PROG13 - Calling Subroutines
;
;  This Application Increments a 16 bit value in a subroutine.
;
;  This program will run in the UMPS simulator for a DS80C320.
;
;  Myke Predko
;  98.02.12
;
;  Hardware Notes:
;   This program is only meant to run on the Simulator

;  Variable Declarations
i EQU 0                         ;  Define the 16 Bit Value to Increment

j EQU 2                         ;  Eight bit Counter

;  Mainline
 org 0                          ;  Execution Starts Here

  ajmp   Mainline


Increment:                      ;  Increment the 16 bit value starting at
                                ;   "i"

  inc    i                      ;  Increment the Low Byte of "i"

  cjne   R0,#0,Inc_Skip         ;  Now, Check it to see if it is zero
  inc    i+1                    ;  The Low Byte is == 0, Increment High Byte
Inc_Skip:

  ret                           ;  Return to caller


Mainline:                       ;  Mainline, Initialize "i" and then
                                ;   Increment it 32x

  mov    i,#0F0h                ;  Initialize it to 0x012F0
  mov    i+1,#012h

  mov    j,#32                  ;  Want to Increment the Number 32x

MLLoop:

  acall  Increment              ;  Now, Increment "i"

  djnz   j,MLLoop               ;  Do 32x


Loop:                           ;  Loop Here Forever when Finished
  ajmp   Loop