Epson S1C62 Family, Справочное руководство

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CROSS ASSEMBLER ASM62XX
S1C62 FAMILY
EPSON
III-11
DEVELOPMENT TOOL REFERENCE MANUAL
4.5 Pseudo-Instructions
There are four types of pseudo-instruction: data definition, memory setting, assembler control, and macro.
These pseudo-instructions as well as operational expressions can be used to govern assembly, and are not
executed in the developed program.
In the subsequent explanations, the items enclosed by < > in the pseudo-instruction format must be written
in the statement (do not write the < > characters themselves). Symbol _ represents one or more blanks or
tabs. One or more symbols and constants or an operational expression can be used in <expression>. See
Section 4.6 for macro functions.
4.5.1
Data definition pseudo-instructions
There are three data definition pseudo-instructions: EQU, SET, and DW. The EQU and SET pseudo-
instructions each define a symbol, and the DW pseudo-instruction presets data in program memory.
■
EQU (Equate)
<Symbol>_EQU_<Expression> To define a symbol
The EQU pseudo-instruction defines <symbol> (written in the label field) as having the value of
<expression> (written in the operand field).
If a value greater than 13 bits is specified in <expression>, bit 14 and subsequent high-order bits are
ignored.
This definition must be made before the symbol is referenced in the program. A U-error occurs if an
attempt is made to reference a symbol that has not been defined.
The same symbol cannot be defined more than once. A P-error occurs if an attempt is made to define a
symbol that has already been defined.
Examples:
ZERO EQU 30H
ONE EQU ZERO+1
ONE EQU 31H
←
P-error because ONE has been defined more than twice
FOUR EQU TWO*2
←
U-error because TWO has not been defined
■
SET
<Symbol>_SET_<Expression> To define a symbol
Like EQU, the SET pseudo-instruction defines the value of <symbol> as being <expression>. The SET
pseudo-instruction allows a symbol to be redefined.
Examples:
ZERO EQU 30H
BIT SET 1
:
BIT SET 2
←
Redefinition possible
:
BIT SET BIT SHL 1
←
Previously-defined items can be referenced