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Motorola HC12 User Manual

Page 237

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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:

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

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

$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

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.