Intel 8080 - B3_Page_33

Chapter 4. Assembler Directives
or IF-ENOl F block so that it can be assembled completely. For example, when a macro definition begins in an
I F block but terminates after an ELSE directive, only a portion of the macro can be assembled. Similarly, an
I F-ENDIF block begun within a macro definition must terminate within that same macro definition.
NOTE
Caution is required when symbols are defined in IF-ENDIF
blocks and referenced elsewhere within the program. These
symbols
are undefined when the evaluation of the IF ex-
pression
suppresse,> the assembly of the IF-ENDIF block.
Example
1. Simple IF-ENDIF Block:
COND1: IF TYPE EQ 0
ENDIF
Example
2. IF-ELSE-Er~DIF Block:
COND2: IF TYPE EQ 0
ELSE
ENDIF
;ASSEMBLED IF 'TYPE = 0'
;IS TRUE
;ASSEMBLED
IF 'TYPE = O·
;IS TRUE
;ASSEMBLED
IF 'TYPE = O·
;IS FALSE
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