Translate and Link Process

Typically you will use the Ax51 assembler and the tools within the µVision IDE. For more information on using the µVision IDE refer to the User's Guide µVision2: Getting Started for 8051.

However, you may invoke the Ax51 assembler also from the command line. Simply type the name of the assembler version that you want to use, for example A51 at the Windows command prompt. On this command line, you must include the name of the assembler source file to be translated, as well as any other necessary control directives required to translate your source file. Example:

A51 DEMO.A51

The assembler output for this command line is:

A51 MACRO ASSEMBLER V6.00
ASSEMBLY COMPLETE.  0 WARNING(S), 0 ERROR(S)

After assembly of all your program modules, the object modules are linked and all variables and addresses are resolved and located into an executable program by the Lx51 linker. The following example shows a simple command line for the linker:

BL51 DEMO.OBJ, PRINT.OBJ

The linker generates an absolute object file as well as a map file that contains detailed statistic information and screen messages. The output of the linker is:

BL51 LINKER/LOCATER V4.00
LINK/LOCATE RUN COMPLETE.  0 WARNING(S),  0 ERROR(S)

Then you might convert the executable program into an Intel HEX file for PROM programming. This is done with the OHx51 hex conversion utility with the following invocation:

OH51 DEMO

The output of the hex conversion utility is:

OBJECT TO HEX FILE CONVERTER OH51 V2.40
GENERATING INTEL HEX FILE: DEMO.HEX
OBJECT TO HEX CONVERSION COMPLETED.

An example listing file generated by the assembler is:

A51 MACRO ASSEMBLER  ASSEMBLER DEMO PROGRAM               07/07/2000 18:32:30 PAGE  1

MACRO ASSEMBLER A51 V6.01
OBJECT MODULE PLACED IN demo.OBJ
ASSEMBLER INVOKED BY: C:\KEIL\C51\BIN\A51.EXE DEMO.A51 DEBUG

LOC  OBJ            LINE     SOURCE

                       1     $title  (ASSEMBLER DEMO PROGRAM)
                       2     ; A simple Assembler Module for Demonstration
                       3
                       4     ; Symbol Definition
  000D                 5     CR      EQU  13         ; Carriage?Return
  000A                 6     LF      EQU  10         ; Line?Feed
                       7
                       8     ; Segment Definition
                       9     ?PR?DEMO  SEGMENT  CODE ; Program Part
                      10     ?CO?DEMO  SEGMENT  CODE ; Constant Part
                      11
                      12     ; Extern Definition
                      13     EXTRN CODE (PRINTS, DEMO)
                      14
                      15     ; The Program Start
----                  16             CSEG  AT  0     ; Reset Vector
0000 020000   F       17             JMP   Start
                      18
----                  19             RSEG  ?PR?DEMO  ; Program Part
0000 900000   F       20     START:  MOV   DPTR,#Txt ; Demo Text
0003 120000   F       21             CALL  PRINTS    ; Print String
                      22     ;
0006 020000   F       23             JMP   DEMO      ; Demo Program
                      24
                      25     ; The Text Constants
----                  26             RSEG  ?CO?DEMO  ; Constant Part
0000 48656C6C         27     Txt:    DB    'Hello World',CR,LF,0
0004 6F20576F
0008 726C640D
000C 0A00
                      28
                      29             END             ; End of Module

SYMBOL TABLE LISTING
------ ----- -------

N A M E             T Y P E  V A L U E   ATTRIBUTES

?CO?DEMO . . . . .  C SEG    000EH       REL=UNIT
?PR?DEMO . . . . .  C SEG    0009H       REL=UNIT
CR . . . . . . . .  N NUMB   000DH   A
DEMO . . . . . . .  C ADDR   -----       EXT
LF . . . . . . . .  N NUMB   000AH   A
PRINTS . . . . . .  C ADDR   -----       EXT
START. . . . . . .  C ADDR   0000H   R   SEG=?PR?DEMO
TXT. . . . . . . .  C ADDR   0000H   R   SEG=?CO?DEMO

REGISTER BANK(S) USED: 0
ASSEMBLY COMPLETE.  0 WARNING(S), 0 ERROR(S)