Motorola HC12 User Manual

User’s Manual

MCUez HC12 Assembler

218

Operating Procedures

MOTOROLA

This section provides operating procedures for the MCUez assembler.

An absolute section has its start address known at assembly time. (See modules
fiboorg.asm and fiboorg.prm in the demo directory.)

An absolute section is defined by the directive

ORG

. The macro assembler

generates a pseudo section named

ORG_

<index>, where <index> is an integer

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