2 introduction, 1 working with absolute sections, Introduction – Motorola HC12 User Manual
Page 218: Working with absolute sections, Operating procedures 11.2 introduction
User’s Manual
MCUez HC12 Assembler
218
Operating Procedures
MOTOROLA
Operating Procedures
11.2 Introduction
This section provides operating procedures for the MCUez assembler.
11.2.1 Working with Absolute Sections
An absolute section has its start address known at assembly time. (See modules
fiboorg.asm and fiboorg.prm in the demo directory.)
11.2.2 Defining Absolute Sections in the Assembly Source File
An absolute section is defined by the directive
ORG
. The macro assembler
generates a pseudo section named
ORG_
which is incremented each time an absolute section is encountered.
Example:
Defining an absolute section containing data:
ORG
$A00
;Absolute constant data section
cst1: DC.B $A6
cst2: DC.B $BC
ORG
$800
; Absolute data section.
var: DS.B 1
In the previous example code, the label
cst1
will be located at address
$A00
,
and label
cst2
will be located at address
$A01
, as shown in this code listing.
1 1 ORG $A00
2 2 a000A00 A6 cst1: DC.B
$A6
3 3 a000A01 BC cst2: DC.B $BC
4 4 ORG
$800
5 5 a000800 var: DS.B 1
Defining an absolute section containing code:
ORG $C00
; Absolute code section.
entry:
ADDA cst2
; Add value in cst2
STAA var
; Store in var
BRA entry