Motorola HC12 User Manual

Operating Procedures

Initializing the Vector Table

MCUez HC12 Assembler

User’s Manual

MOTOROLA

Operating Procedures

227

NOTE:

Each constant in the section

VectorTable

is defined as a word (2-byte

constant) because the entries in the HC12 vector table are 16 bits wide. In the
previous example, the constant

XIRQInt

is initialized with the address of the

label

XIRQFunc

. The constant

COPResetInt

is initialized with the address

of the label

DummyFunc

because this interrupt is not in use. All labels specified

as initialization values must be defined, published (using XDEF), or imported
(using XREF) before the vector table section.

The section should now be placed at the expected address. This is performed in
the linker parameter file.

Example:

LINK test.abs

NAMES test.o END

SEGMENTS

MY_ROM = READ_ONLY 0x0800 TO 0x08FF;

MY_RAM = READ_WRITE 0x0A00 TO 0x0BFF;

/* Define the memory range for the vector table */

Vector = READ_ONLY 0xFFF2 TO 0xFFFF;

END

PLACEMENT

DEFAULT_RAM INTO MY_RAM;

DEFAULT_ROM INTO MY_ROM;

/* Place the section ‘VectorTable’ at the appropriated

address */

VectorTable INTO Vector;

END

INIT ResetFunc

ENTRIES

END