Texas Instruments TI-89 Software Guide

Section 3: Assembler
241
TI
-
89 / TI
-
92 Plus Sierra C Assembler Reference Manual
Not for Distribution
Beta Version February 2, 2001
IFNC — Assemble If Strings Not Equal
Syntax
IFNC '
string1
', '
string2
'
Description
string1
Specifies an ASCII string. It can include whitespace and commas.
string2
Specifies an ASCII string. It can include whitespace and commas.
The
IFNC
directive introduces a conditional assembly block. If the specified
strings
string1
and
string2
are not equal, then the statements between this
directive and the first matching
ELSEC
or
ENDC
directive are assembled, and
the remainder of the block is skipped. Otherwise, the statements associated with
the
IFNC
directive are skipped and control passes to the aforementioned
matching directive.
The
IFNC
directive is useful only within user-defined macros (e.g., testing for null
parameters). The single quotes that enclose each string need not appear literally
in the operand field of this directive prior to macro expansion

i.e., they can be
included in an actual parameter.
Conditional assembly directives can be nested to 40 levels.
Example
IFNC '\1',''
MOVE.W D0,D3
ENDC

Texas Instruments TI-89 Specifications

General

Display size (HxV)	100 x 160 mm
Memory type	639K FLASH ROM, 188K bytes RAM
Compatible operating systems	Operating System 2.09
Battery type	AAA