Zilog ZUSBOPTS - Manual (Page 267)

UM017105-0511 Directives
Zilog Developer Studio II – ZNEO™
User Manual
239
Synonyms
.extern , EXTERN , EXTERNAL , .ref
Syntax
<xref_directive> => XREF <ident_space_list>

<ident_space_list> => <ident_space>

=> <ident_space_list>, <ident_space>

<ident_space> => <ident> [:<space>]
Examples
XREF label

XREF label1,label2,label3

XREF label:ROM
Structures and Unions in Assembly Code
The assembler provides a set of directives to group data elements together, similar to high-
level programming language constructs like a C structure or a Pascal record. These direc-
tives allow you to declare a structure or union type consisting of various elements, assign
labels to be of previously declared structure or union type, and provide multiple ways to
access elements at an offset from such labels.
The assembler directives associated with structure and union support are listed in
Table 21:
These structure and union directives are described in the following sections:
•
.STRUCT and .ENDSTRUCT Directives – see page 240
•
.TAG Directive – see page 241
•
.UNION Directive – see page 242
•
.WITH and .ENDWITH Directives – see page 243
Table 21. Structure and Union Assembler Directives
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.