Texas Instruments TMS320C3 Series, User Manual, Page: 105 / 166

Assemble Conditional Block
.if, .else, .endif
6-23 Assembler Directives
Syntax .if
well-defined expression
.else
.endif
Description Three directives provide conditional assembly:
-
The .if directive marks the beginning of a conditional block. The expres-
sion is a required parameter.
J
If the expression evaluates to true (nonzero), the assembler as-
sembles the code that follows it (up to an .else, or an .endif).
J
If the expression evaluates to false (0), the assembler assembles
code that follows an .else (if present), or an .endif.
-
The .else directive identifies a block of code that the assembler assembles
when the .if expression is false (0). This directive is optional in the condi-
tional block; if an expression is false and there is no .else statement, the
assembler continues with the code that follows the .endif.
-
The .endif directive terminates a conditional block.
Nested .if/.else/.endif directives are not valid.
Example Here is an example of conditional assembly:
TRUE .set 1
FALSE .set 0
.if TRUE ;
nop ; Assembles ’nop’ since TRUE
.else ;
B $ ; Never assembles
.endif ;