Motorola HC12 User Manual
Operating Procedures
Directly Generating an .abs File
MCUez HC12 Assembler
User’s Manual
MOTOROLA
Operating Procedures
237
When writing an assembly source file for direct absolute file generation, pay
special attention to these points:
special attention to these points:
•
The directive
ABSENTRY
is used to write the entry point address in the
generated absolute file. To set the entry point of the application to the
label
label
entry
in the absolute file, this code is needed:
ABSENTRY entry
•
The reset vector must be initialized in the assembly source file,
specifying the application entry point. An absolute section is created at
the reset vector address. This section contains the application entry point
address.
To set the entry point of the application at address
specifying the application entry point. An absolute section is created at
the reset vector address. This section contains the application entry point
address.
To set the entry point of the application at address
$FFFE
to the label
entry
, this code is needed:
ORG $FFFE
; Reset vector definition
Reset:DC.W entry
•
It is strongly recommended to use separate sections for code, data, and
constants. All sections used in the assembler application must be
absolute. They must be defined using the
constants. All sections used in the assembler application must be
absolute. They must be defined using the
ORG
directive. The address for
constant or code sections has to be located in the
ROM
memory area,
while the data sections have to be located in the
RAM
area (according to
the hardware used). The programmer must ensure that no sections
overlap.
overlap.