CHAPTER 4: ASSEMBLER

Precautions

•The assembler only permits backward reference of a Define name. Therefore the name definition must precede the use of it.

•Once a Define name is defined, it cannot be canceled. However, redefinition can be made using another Define name.

Example:

#define XL %xl #define Xlow XL

ldb [Xlow],%ba

... Expanded to "ldb [%xl],%ba".

•When the same Define name is defined duplicatedly, a warning message will appear. Until it is redefined, it is expanded with the original content, and once it is redefined, it is expanded with the new content.

•No other characters than delimiters (space, tab, line feed, and comma) can be added before and after a Define name in the source, unless they are enclosed in [ ] or [ ]+. However, an operator or a symbol mask (@..) can be added to a Define name string without delimiters.

Examples:

#define

INT_F

0xfff

 

 

 

tst

[INT_F1],0 ;tst [0xfff1],0? ... Specification like this is invalid.

#define

L

LABEL

 

 

 

ldb

%ext,L@h

... Replaced with "ldb

%ext,LABEL@h".

 

ldb

%xl,L@l

... Replaced with "ldb

%xl,LABEL@l".

•When using an expression in a #define statement, it will be expanded as is. Pay attention when a number is defined using the #define pseudo-instruction.

Examples:

#define NUM1 1+1

 

ld

%a,NUM1*2

... Expanded as "ld

%a, 1+1*2" (=3).

#define

NUM2

(1+1)

 

 

 

ld

%a,NUM2*2

... Expanded as "ld

%a, (1+1)*2" (=4).

•The internal preprocess part of the assembler does not check the validity of a statement as the result of the replacement of the character string.

66

EPSON

S5U1C63000A MANUAL

 

 

(S1C63 FAMILY ASSEMBLER PACKAGE)