Motorola HC12 - Manual (Page 225)

Operating Procedures
Initializing the Vector Table
MCUez HC12 Assembler User’s Manual
MOTOROLA Operating Procedures 225
NOTE: The functions XIRQFunc, SWIFunc, and ResetFunc are published. This
is required because they are referenced in the linker PRM file. All interrupt
functions must be terminated with an RTI instruction.
The vector table is initialized using the linker command VECTOR ADDRESS.
Example:
LINK test.abs
NAMES
test.o
END
SEGMENTS
MY_ROM = READ_ONLY 0x0800 TO 0x08FF;
MY_RAM = READ_WRITE 0x0B00 TO 0x0CFF;
END
PLACEMENT
.data INTO MY_RAM;
.text INTO MY_ROM;
END
INIT ResetFunc
VECTOR ADDRESS 0xFFF2 IRQFunc
VECTOR ADDRESS 0xFFF4 XIRQFunc
VECTOR ADDRESS 0xFFF6 SWIFunc
VECTOR ADDRESS 0xFFF8 OpCodeFunc
VECTOR ADDRESS 0xFFFE ResetFunc
NOTE: The statement INIT ResetFunc defines the application entry point. Usually,
this entry point is initialized with the same address as the reset vector. The
statement
VECTOR ADDRESS 0xFFF4 XIRQFunc specifies that the
address of function XIRQFunc should be written at address 0xFFF4 .
11.4.2 Initializing Vector Table in Assembly Source Files Using a Relocatable Section
Initializing the vector table in the assembly source file requires that all entries
in the table are initialized. Interrupts that are not used must be associated with
a standard handler.
The labels or functions, which should be inserted in the vector table, must be
implemented in the assembler source file or an external reference must be
available for them. The vector table can be defined in an assembly source file
in an additional section containing constant variables.