<html lang="en">
<head>
<title>Xtensa Registers - Using as</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="Using as">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Xtensa-Syntax.html#Xtensa-Syntax" title="Xtensa Syntax">
<link rel="prev" href="Xtensa-Opcodes.html#Xtensa-Opcodes" title="Xtensa Opcodes">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
This file documents the GNU Assembler "as".
Copyright (C) 1991-2015 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''.
-->
<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; }
span.sansserif { font-family:sans-serif; font-weight:normal; }
--></style>
</head>
<body>
<div class="node">
<a name="Xtensa-Registers"></a>
<p>
Previous: <a rel="previous" accesskey="p" href="Xtensa-Opcodes.html#Xtensa-Opcodes">Xtensa Opcodes</a>,
Up: <a rel="up" accesskey="u" href="Xtensa-Syntax.html#Xtensa-Syntax">Xtensa Syntax</a>
<hr>
</div>
<h5 class="subsubsection">9.52.2.2 Register Names</h5>
<p><a name="index-Xtensa-register-names-2456"></a><a name="index-register-names_002c-Xtensa-2457"></a><a name="index-sp-register-2458"></a>
The assembly syntax for a register file entry is the “short” name for
a TIE register file followed by the index into that register file. For
example, the general-purpose <code>AR</code> register file has a short name of
<code>a</code>, so these registers are named <code>a0</code><small class="dots">...</small><code>a15</code>.
As a special feature, <code>sp</code> is also supported as a synonym for
<code>a1</code>. Additional registers may be added by processor configuration
options and by designer-defined TIE extensions. An initial ‘<samp><span class="samp">$</span></samp>’
character is optional in all register names.
</body></html>