| <html lang="en"> |
| <head> |
| <title>S12Z Syntax Overview - 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="S12Z-Syntax.html#S12Z-Syntax" title="S12Z Syntax"> |
| <link rel="next" href="S12Z-Addressing-Modes.html#S12Z-Addressing-Modes" title="S12Z Addressing Modes"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| This file documents the GNU Assembler "as". |
| |
| Copyright (C) 1991-2019 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="S12Z-Syntax-Overview"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="S12Z-Addressing-Modes.html#S12Z-Addressing-Modes">S12Z Addressing Modes</a>, |
| Up: <a rel="up" accesskey="u" href="S12Z-Syntax.html#S12Z-Syntax">S12Z Syntax</a> |
| <hr> |
| </div> |
| |
| <h5 class="subsubsection">9.24.2.1 Overview</h5> |
| |
| <p>In the S12Z syntax, the instruction name comes first and it may |
| be followed by one, or by several operands. |
| In most cases the maximum number of operands is three. |
| Operands are separated by a comma (‘<samp><span class="samp">,</span></samp>’). |
| A comma however does not act as a separator if it appears within parentheses |
| (‘<samp><span class="samp">()</span></samp>’) or within square brackets (‘<samp><span class="samp">[]</span></samp>’). |
| <code>as</code> will complain if too many, too few or inappropriate operands |
| are specified for a given instruction. |
| |
| <p>Some instructions accept and (in certain situations require) a suffix |
| indicating the size of the operand. |
| The suffix is separated from the instruction name by a period (‘<samp><span class="samp">.</span></samp>’) |
| and may be one of ‘<samp><span class="samp">b</span></samp>’, ‘<samp><span class="samp">w</span></samp>’, ‘<samp><span class="samp">p</span></samp>’ or ‘<samp><span class="samp">l</span></samp>’ indicating |
| `byte' (a single byte), `word' (2 bytes), `pointer' (3 bytes) or `long' (4 bytes) |
| respectively. |
| |
| <p>Example: |
| |
| <pre class="smallexample"> bset.b 0xA98, #5 |
| mov.b #6, 0x2409 |
| ld d0, #4 |
| mov.l (d0, x), 0x2409 |
| inc d0 |
| cmp d0, #12 |
| blt *-4 |
| lea x, 0x2409 |
| st y, (1, x) |
| </pre> |
| <p><a name="index-line-comment-character_002c-S12Z-1524"></a>The presence of a ‘<samp><span class="samp">;</span></samp>’ character anywhere |
| on a line indicates the start of a comment that extends to the end of |
| that line. |
| |
| <p>A ‘<samp><span class="samp">*</span></samp>’ or a ‘<samp><span class="samp">#</span></samp>’ character at the start of a line also |
| introduces a line comment, but these characters do not work elsewhere |
| on the line. If the first character of the line is a ‘<samp><span class="samp">#</span></samp>’ then as |
| well as starting a comment, the line could also be logical line number |
| directive (see <a href="Comments.html#Comments">Comments</a>) or a preprocessor control command |
| (see <a href="Preprocessing.html#Preprocessing">Preprocessing</a>). |
| |
| <p><a name="index-line-separator_002c-S12Z-1525"></a><a name="index-statement-separator_002c-S12Z-1526"></a><a name="index-S12Z-line-separator-1527"></a>The S12Z assembler does not currently support a line separator |
| character. |
| |
| </body></html> |
| |
