Texas Instruments TMS320C54x, User Manual

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Directives That Reference Other Files
4-19 Assembler Directives
4.7 Directives That Reference Other Files
These directives supply information for or about other files:
-
The .copy and .include directives tell the assembler to begin reading
source statements from another file. When the assembler finishes reading
the source statements in the copy/include file, it resumes reading source
statements from the current file. The statements read from a copied file are
printed in the listing file; the statements read from an included file are
not
printed in the listing file.
-
The .def directive identifies a symbol that is defined in the current module
and that can be used by another module. The assembler includes the
symbol in the symbol table.
-
The .global directive declares a symbol external so that it is available to
other modules at link time. (For more information about global symbols,
see subsection 2.8.1,
External Symbols, on page 2-19.) The .global
directive does double duty, acting as a .def for defined symbols and as a
.ref for undefined symbols. The linker resolves an undefined global symbol
only if it is used in the program.
-
The .ref directive identifies a symbol that is used in the current module but
defined in another module. The assembler marks the symbol as an
undefined external symbol and enters it in the object symbol table so that
the linker can resolve its definition.