8080/8085 Assembler Assembler Overview

Symbol-Cross-Reference

File

During the first pass
of
the assembler, a file
of
symbol-cross-reference records
is
created, if requested. This diskette file
is
named ASXREF . TMP .
In general, the assembler generates two types
of
symbol-cross-reference records:

symbol-definition

records

and

symbol-reference

records.

If
a symbol appears as a
name in a label field and the symbol
is
being defined (by SET, EQU, MACRO, or as
a label), a symbol-definition record
is
produced.
If
the symbol
is
being redefined by
SET
or
MACRO, it
is
considered a symbol definition. All other symbol occurrences
are considered references and cause the assembler to generate a symbol-reference
record each time the symbol appears. Symbol definition records are terminated by a
pound sign
(##)
in the cross-reference listing.
All symbols are cross referenced except dummy parameters and local labels appear-
ing in macro definitions (that is, all global user-defined symbols, macro names, and
actual symbols replacing dummy parameters or local labels are cross referenced).
When certain controls that suppress source listing are specified (NOLIST, NOGEN,
NOCOND), symbols not listed are not cross referenced.
The assembler calls on ISIS-II to load its cross-reference-generator program and
ASXREF.TMP from the diskette. From the programmer's point
of
view,
the opera-
tions required to produce the cross-reference listing are automatic (once the cross
reference file has been requested). The format
of
the cross-reference listing
is
shown
in Chapter 4.
Assembler Files
The ISIS-II assembler uses several files
of
its own, such as the intermediate cross-
reference file just mentioned. While you
don't
need to remember the names of these
files, you must know where they reside to avoid diskette space conflict.
The assembler root program (ASM80) and its overlays (ASM80.0Vn, where
n=O,
1 ,2 ... ) must reside
on
the same diskette, but this diskette can be on any drive.
The cross-reference generator (ASXREF) must reside on this diskette also.
The intermediate cross-reference file (ASXREF.
TMP)
is
written to the drive con-
taining your source file. The MACROFILE control determines where the in-
termediate macro file (ASMAC. TMP)
is
written; the default
is
the source file drive.
The list and object files can be directed to any drive via assembler controls. The
default sends these files to the source file drive.
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