CHAPTER 4: ASSEMBLER

4.5 Grammar of Assembly Source

Assembly source files should be created on a general-purpose editor or the source editor of the work bench. Save sources as standard text files. For the file name, a long file name supported in Windows can be specified.

This section explains the rules and grammar involved with the creation of assembly source files.

4.5.1 Statements

Each individual instruction or definition of an assembly source is called a statement. The basic composition of a statement is as follows:

Syntax pattern

(1) Mnemonic

 

 

Operand

(;comment)

(2) Assembler pseudo-instruction

Parameter

(;comment)

(3) Label:

 

 

 

(;comment)

(4) ;comment

 

 

 

 

Example:

<Statement>

 

<Syntax Pattern>

#include

"define.h"

 

(2)

 

.set

IO1, 0xfff1

 

(2)

; TEXT SECTION (ROM, 13bit width)

(4)

 

.org

0x100

 

(2)

NMI:

 

 

 

(3)

 

reti

 

 

(1)

 

nop

 

 

(1)

 

nop

 

 

(1)

 

jr

NMI

 

(1)

 

.org

0x110

 

(2)

BOOT:

 

 

 

(3)

 

ld

%f,0x4

 

(1)

 

ld

%a,0

 

(1)

 

ld

%a,0

 

(1)

 

ldb

%ext,0 ; clear memory 0 to 3

(1)

 

:

 

:

 

The example given above is an ordinary source description method. For increased visibility, the elements composing each statement are aligned with tabs and spaces.

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