Motorola M68CPU32BUG Manuale Utente Scaricare il pdf (Pagina 6)

• mnemonics representing executableinstructions and assembler directives should begin

after a TAB as in:

ORG $3000

CLR.L D1

CLR.L D2 * executable instructions should start after a TAB

• The assembler is very particular about whitespace characters between operands or

labels as in:

ADD D0, D1 * this will assemble with 0 warnings 0 error

* but the machine code generated will be

* INCORRECT.

ADD D0,D1 * note no blank after the , this is CORRECT

* and will produce correct machine code.

LOOP:

DBRA D3, LOOP * this will assemble, but the machine code

* will be incorrect but no errors will be

* reported by the assembler.

LOOP:

DBRA D3,LOOP * this is correct, note that there is no

* space after the ,

To assemble the program perform the following steps:

1. Open a command prompt (Start --> Accessories --> Command Prompt)

2. Issue the command: path=%path%;”C:\Program Files\as32” This com-

mand will add the location of the assembler program to the shell path variable.

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Motorola M68CPU32BUG Manuale Utente Pagina 6