huangmeng
/
asj_pe_project


			
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182
							<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- This file documents the GNU Assembler "as".

Copyright (C) 1991-2020 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts.  A copy of the license is included in the
section entitled "GNU Free Documentation License".
 -->
<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Using as: Z80 Directives</title>

<meta name="description" content="Using as: Z80 Directives">
<meta name="keywords" content="Using as: Z80 Directives">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Z80_002dDependent.html#Z80_002dDependent" rel="up" title="Z80-Dependent">
<link href="Z80-Opcodes.html#Z80-Opcodes" rel="next" title="Z80 Opcodes">
<link href="Z80-Floating-Point.html#Z80-Floating-Point" rel="previous" title="Z80 Floating Point">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Z80-Directives"></a>
<div class="header">
<p>
Next: <a href="Z80-Opcodes.html#Z80-Opcodes" accesskey="n" rel="next">Z80 Opcodes</a>, Previous: <a href="Z80-Floating-Point.html#Z80-Floating-Point" accesskey="p" rel="previous">Z80 Floating Point</a>, Up: <a href="Z80_002dDependent.html#Z80_002dDependent" accesskey="u" rel="up">Z80-Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Z80-Assembler-Directives"></a>
<h4 class="subsection">9.56.4 Z80 Assembler Directives</h4>
<a name="index-Z80_002donly-directives"></a>

<p><code>as</code> for the Z80 supports some additional directives for
compatibility with other assemblers.
</p>
<p>These are the additional directives in <code>as</code> for the Z80:
</p>
<dl compact="compact">
<dt><code><code>.assume ADL = <var>expression</var></code></code></dt>
<dd><a name="index-_002eassume-directive_002c-Z80"></a>
<p>Set ADL status for eZ80. Non-zero value enable compilation in ADL mode else
used Z80 mode. ADL and Z80 mode produces incompatible object code. Mixing
both of them within one binary may lead problems with disassembler.
</p>
</dd>
<dt><code><code>db <var>expression</var>|<var>string</var>[,<var>expression</var>|<var>string</var>...]</code></code></dt>
<dd><a name="index-db-directive_002c-Z80"></a>
</dd>
<dt><code><code>defb <var>expression</var>|<var>string</var>[,<var>expression</var>|<var>string</var>...]</code></code></dt>
<dd><a name="index-defb-directive_002c-Z80"></a>
</dd>
<dt><code><code>defm <var>string</var>[,<var>string</var>...]</code></code></dt>
<dd><a name="index-defm-directive_002c-Z80"></a>
<p>For each <var>string</var> the characters are copied to the object file, for
each other <var>expression</var> the value is stored in one byte.
A warning is issued in case of an overflow.
Backslash symbol in the strings is generic symbol, it cannot be used as
escape character.  See <a href="Ascii.html#Ascii"><code>.ascii</code></a>.
</p>
</dd>
<dt><code><code>dw <var>expression</var>[,<var>expression</var>...]</code></code></dt>
<dd><a name="index-dw-directive_002c-Z80"></a>
</dd>
<dt><code><code>defw <var>expression</var>[,<var>expression</var>...]</code></code></dt>
<dd><a name="index-defw-directive_002c-Z80"></a>
<p>For each <var>expression</var> the value is stored in two bytes, ignoring
overflow.
</p>
</dd>
<dt><code><code>d24 <var>expression</var>[,<var>expression</var>...]</code></code></dt>
<dd><a name="index-d24-directive_002c-Z80"></a>
</dd>
<dt><code><code>def24 <var>expression</var>[,<var>expression</var>...]</code></code></dt>
<dd><a name="index-def24-directive_002c-Z80"></a>
<p>For each <var>expression</var> the value is stored in three bytes, ignoring
overflow.
</p>
</dd>
<dt><code><code>d32 <var>expression</var>[,<var>expression</var>...]</code></code></dt>
<dd><a name="index-d32-directive_002c-Z80"></a>
</dd>
<dt><code><code>def32 <var>expression</var>[,<var>expression</var>...]</code></code></dt>
<dd><a name="index-def32-directive_002c-Z80"></a>
<p>For each <var>expression</var> the value is stored in four bytes, ignoring
overflow.
</p>
</dd>
<dt><code><code>ds <var>count</var>[, <var>value</var>]</code></code></dt>
<dd><a name="index-ds-directive_002c-Z80"></a>
</dd>
<dt><code><code>defs <var>count</var>[, <var>value</var>]</code></code></dt>
<dd><a name="index-defs-directive_002c-Z80"></a>
<p>Fill <var>count</var> bytes in the object file with <var>value</var>, if
<var>value</var> is omitted it defaults to zero.
</p>
</dd>
<dt><code><code><var>symbol</var> defl <var>expression</var></code></code></dt>
<dd><a name="index-defl-directive_002c-Z80"></a>
<p>The <code>defl</code> directive is like <code>.set</code> but with different
syntax.  See <a href="Set.html#Set"><code>.set</code></a>.
It set the value of <var>symbol</var> to <var>expression</var>. Symbols defined
with <code>defl</code> are not protected from redefinition.
</p>
</dd>
<dt><code><code><var>symbol</var> equ <var>expression</var></code></code></dt>
<dd><a name="index-equ-directive_002c-Z80"></a>
<p>The <code>equ</code> directive is like <code>.equiv</code> but with different
syntax.  See <a href="Equiv.html#Equiv"><code>.equiv</code></a>.
It set the value of <var>symbol</var> to <var>expression</var>. It is an error
if <var>symbol</var> is already defined. Symbols defined with <code>equ</code>
are not protected from redefinition.
</p>
</dd>
<dt><code><code>psect <var>name</var></code></code></dt>
<dd><a name="index-psect-directive_002c-Z80"></a>
<p>A synonym for <code>.section</code>, no second argument should be given.
See <a href="Section.html#Section"><code>.section</code></a>.
</p>
</dd>
<dt><code><code>xdef <var>symbol</var></code></code></dt>
<dd><a name="index-xdef-directive_002c-Z80"></a>
<p>A synonym for <code>.global</code>, make <var>symbol</var> is visible to linker.
See <a href="Global.html#Global"><code>.global</code></a>.
</p>
</dd>
<dt><code><code>xref <var>name</var></code></code></dt>
<dd><a name="index-xref-directive_002c-Z80"></a>
<p>A synonym for <code>.extern</code> (<a href="Extern.html#Extern"><code>.extern</code></a>).
</p>
</dd>
</dl>

<hr>
<div class="header">
<p>
Next: <a href="Z80-Opcodes.html#Z80-Opcodes" accesskey="n" rel="next">Z80 Opcodes</a>, Previous: <a href="Z80-Floating-Point.html#Z80-Floating-Point" accesskey="p" rel="previous">Z80 Floating Point</a>, Up: <a href="Z80_002dDependent.html#Z80_002dDependent" accesskey="u" rel="up">Z80-Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
</div>


</body>
</html>