neingeist
/
arduinisten
Archived
1
0
Fork 0
You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
This repo is archived. You can view files and clone it, but cannot push or open issues/pull-requests.

90 lines
4.4 KiB
HTML

<html lang="en">
<head>
<title>Z80 Opcodes - Using as</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="Using as">
<meta name="generator" content="makeinfo 4.7">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Z80_002dDependent.html#Z80_002dDependent" title="Z80-Dependent">
<link rel="prev" href="Z80-Directives.html#Z80-Directives" title="Z80 Directives">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
This file documents the GNU Assembler "as".
Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
2006, 2007 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 1.1
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''.
man end-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
pre.display { font-family:inherit }
pre.format { font-family:inherit }
pre.smalldisplay { font-family:inherit; font-size:smaller }
pre.smallformat { font-family:inherit; font-size:smaller }
pre.smallexample { font-size:smaller }
pre.smalllisp { font-size:smaller }
span.sc { font-variant:small-caps }
span.roman { font-family: serif; font-weight: normal; }
--></style>
</head>
<body>
<div class="node">
<p>
<a name="Z80-Opcodes"></a>Previous:&nbsp;<a rel="previous" accesskey="p" href="Z80-Directives.html#Z80-Directives">Z80 Directives</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="Z80_002dDependent.html#Z80_002dDependent">Z80-Dependent</a>
<hr><br>
</div>
<h4 class="subsection">9.32.5 Opcodes</h4>
<p>In line with common practice, Z80 mnemonics are used for both the Z80 and
the R800.
<p>In many instructions it is possible to use one of the half index
registers (<span class="samp">ixl</span>,<span class="samp">ixh</span>,<span class="samp">iyl</span>,<span class="samp">iyh</span>) in stead of an
8-bit general purpose register. This yields instructions that are
documented on the R800 and undocumented on the Z80.
Similarly <code>in f,(c)</code> is documented on the R800 and undocumented on
the Z80.
<p>The assembler also supports the following undocumented Z80-instructions,
that have not been adopted in the R800 instruction set:
<dl>
<dt><code>out (c),0</code><dd>Sends zero to the port pointed to by register c.
<br><dt><code>sli </code><var>m</var><dd>Equivalent to <var>m</var><code> = (</code><var>m</var><code>&lt;&lt;1)+1</code>, the operand <var>m</var> can
be any operand that is valid for <span class="samp">sla</span>. One can use <span class="samp">sll</span> as a
synonym for <span class="samp">sli</span>.
<br><dt><var>op</var><code> (ix+</code><var>d</var><code>), </code><var>r</var><dd>This is equivalent to
<pre class="example"> ld <var>r</var>, (ix+<var>d</var>)
<var>opc</var> <var>r</var>
ld (ix+<var>d</var>), <var>r</var>
</pre>
<p>The operation <var>opc</var> may be any of <span class="samp">res </span><var>b</var><span class="samp">,</span>,
<span class="samp">set </span><var>b</var><span class="samp">,</span>, <span class="samp">rl</span>, <span class="samp">rlc</span>, <span class="samp">rr</span>, <span class="samp">rrc</span>,
<span class="samp">sla</span>, <span class="samp">sli</span>, <span class="samp">sra</span> and <span class="samp">srl</span>, and the register
<var>r</var> may be any of <span class="samp">a</span>, <span class="samp">b</span>, <span class="samp">c</span>, <span class="samp">d</span>,
<span class="samp">e</span>, <span class="samp">h</span> and <span class="samp">l</span>.
<br><dt><var>opc</var><code> (iy+</code><var>d</var><code>), </code><var>r</var><dd>As above, but with <span class="samp">iy</span> instead of <span class="samp">ix</span>.
</dl>
<p>The web site at <a href="http://www.z80.info">http://www.z80.info</a> is a good starting place to
find more information on programming the Z80.
<!-- Copyright 1991, 1992, 1993, 1994, 1995, 2003 -->
<!-- Free Software Foundation, Inc. -->
<!-- This is part of the GAS manual. -->
<!-- For copying conditions, see the file as.texinfo. -->
</body></html>