Zilog EZ80F916 User Manual
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ZiLOG Developer Studio II
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User Manual
211
The assembler directives associated with structure and union support are listed in the fol-
lowing table:
These directives are described in the following sections:
•
“.STRUCT and .ENDSTRUCT Directives” on page 211
•
•
“.UNION Directive” on page 214
•
“.WITH and .ENDWITH Directives” on page 215
.STRUCT and .ENDSTRUCT Directives
A structure is a collection of various elements grouped together under a single name for
convenient handling. The
.STRUCT
and
.ENDSTRUCT
directives can be used to define the
layout for a structure in assembly by identifying the various elements and their sizes. The
.STRUCT
directive assigns symbolic offsets to the elements of a structure. It does not allo-
cate memory. It merely creates a symbolic template that can be used repeatedly.
The
.STRUCT
and
.ENDSTRUCT
directives have the following form:
[stag]
.STRUCT
[offset | : parent]
[name_1]
DS
count1
[name_2]
DS
count2
[tname]
.TAG
stagx [count]
...
[name_n]
DS
count3
[ssize]
.ENDSTRUCT
[stag]
The label stag defines a symbol to use to reference the structure; the expression offset, if
used, indicates a starting offset value to use for the first element encountered; otherwise,
the starting offset defaults to zero.
Assembler Directive
Description
.STRUCT
Group data elements in a structure type
.ENDSTRUCT
Denotes end of structure or union type
.UNION
Group data elements in a union type
.TAG
Associate label with a structure or union type
.WITH
A section in which the specified label or structure tag is implicit
.ENDWITH
Denotes end of with section