Chapter 9 Writing Machine Language Instructions and Directive Statements

9.4.10 dc

Syntax

label

operation

operand

[name]

dc

constant expression (, constant expression )...

Functional description

This directive is used to define constants in a memory area. The 8-bit constant specified by the operand will be stored at the location of the statement specifying this directive.

When a name is coded for the label, the assembler will assign the current location counter value to that name.

Operand coding rules

The expression coded in the operand must result in the attribute abs(absolute).

Refer to section 8.7.4 “Expression Attributes”, regafding attributes of expressions.

Specify one of the following constants or the operand.

character constant

string constant

The operands are delimited with commas (,). Any number of operands can be coded.

If data that exceeds 8 bits is specified, the lower 8 bits will be valid, and the upper bits will be lost. The assembler will output a warning message in such cases.

When the specified data has fewer than 8 bits, those bits will fill the lower bits, and the upper bits will be padded with zeroes.

Usage example

Below is an example use of the dc directive.

 

 

 

 

DC.LST

Page 1

 

*** PanaX Series MN1030 Cross Assembler ***

Loc

Object

Line

Source

 

 

 

1

_DATA

section

DATA,PUBLIC,4

00000000

41

2

cd0

dc

’A’

00000001

414243

3

cd1

dc

“ABC”

00000004

3F

4

cd2

dc

255 >> 2

00000005

0E

5

cd3

dc

(12+3)/2*2

00000006

FF

6

cd4

dc

0b11111111

00000007

FFFE

7

cd5

dc

0377, 0376

00000009

FF

8

cd6

dc

255

166 Writing Directive Statements

Page 178
Image 178
Panasonic MN1030 user manual 10 dc