NOTE
Assembler Directives and
.EQU Directive
.EQU Directive
The .EQU directive assigns an expression value to an identifier.
Syntax
symbolic_name .EQU value
Parameters
symbolic_name The name of the identifier to which the Assembler
| assigns the expression. |
value | An integer expression. The Assembler evaluates the |
| expression, which must be absolute, and assigns this |
| value to symbolic_name. If the expression references |
| other identifiers, each identifier must be defined before |
| the .EQU directive attempts to evaluate the expression. |
The Assembler prohibits the use of relocatable symbols (instruction labels) and imported symbols as components of an .EQU expression.
Example
This is a valid assembly program because the definition of val1 comes before the definition of val2. Reversing the first two statements, however, produces an error condition.
val1 .EQU 0
val2 .EQU val1+4
.SPACE $TEXT$
.SUBSPA $CODE$ LDW val1,%r1 STW %r1,val2
.END
84 | Chapter 4 |