mirror of
https://github.com/mre/mos6502.git
synced 2024-12-23 03:29:51 +00:00
376 lines
8.6 KiB
HTML
376 lines
8.6 KiB
HTML
<?xml version="1.0" encoding="utf-8"?>
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
|
|
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
|
|
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
|
|
<head>
|
|
<title>6502Arch</title>
|
|
<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
|
|
<meta name="title" content="6502Arch"/>
|
|
<meta name="generator" content="Org-mode"/>
|
|
<meta name="generated" content="2014-09-25T21:09-0400"/>
|
|
<meta name="author" content="Alex Weisberger"/>
|
|
<meta name="description" content=""/>
|
|
<meta name="keywords" content=""/>
|
|
<style type="text/css">
|
|
<!--/*--><![CDATA[/*><!--*/
|
|
html { font-family: Times, serif; font-size: 12pt; }
|
|
.title { text-align: center; }
|
|
.todo { color: red; }
|
|
.done { color: green; }
|
|
.tag { background-color: #add8e6; font-weight:normal }
|
|
.target { }
|
|
.timestamp { color: #bebebe; }
|
|
.timestamp-kwd { color: #5f9ea0; }
|
|
.right {margin-left:auto; margin-right:0px; text-align:right;}
|
|
.left {margin-left:0px; margin-right:auto; text-align:left;}
|
|
.center {margin-left:auto; margin-right:auto; text-align:center;}
|
|
p.verse { margin-left: 3% }
|
|
pre {
|
|
border: 1pt solid #AEBDCC;
|
|
background-color: #F3F5F7;
|
|
padding: 5pt;
|
|
font-family: courier, monospace;
|
|
font-size: 90%;
|
|
overflow:auto;
|
|
}
|
|
table { border-collapse: collapse; }
|
|
td, th { vertical-align: top; }
|
|
th.right { text-align:center; }
|
|
th.left { text-align:center; }
|
|
th.center { text-align:center; }
|
|
td.right { text-align:right; }
|
|
td.left { text-align:left; }
|
|
td.center { text-align:center; }
|
|
dt { font-weight: bold; }
|
|
div.figure { padding: 0.5em; }
|
|
div.figure p { text-align: center; }
|
|
div.inlinetask {
|
|
padding:10px;
|
|
border:2px solid gray;
|
|
margin:10px;
|
|
background: #ffffcc;
|
|
}
|
|
textarea { overflow-x: auto; }
|
|
.linenr { font-size:smaller }
|
|
.code-highlighted {background-color:#ffff00;}
|
|
.org-info-js_info-navigation { border-style:none; }
|
|
#org-info-js_console-label { font-size:10px; font-weight:bold;
|
|
white-space:nowrap; }
|
|
.org-info-js_search-highlight {background-color:#ffff00; color:#000000;
|
|
font-weight:bold; }
|
|
/*]]>*/-->
|
|
</style>
|
|
<script type="text/javascript">
|
|
/*
|
|
@licstart The following is the entire license notice for the
|
|
JavaScript code in this tag.
|
|
|
|
Copyright (C) 2012-2013 Free Software Foundation, Inc.
|
|
|
|
The JavaScript code in this tag is free software: you can
|
|
redistribute it and/or modify it under the terms of the GNU
|
|
General Public License (GNU GPL) as published by the Free Software
|
|
Foundation, either version 3 of the License, or (at your option)
|
|
any later version. The code is distributed WITHOUT ANY WARRANTY;
|
|
without even the implied warranty of MERCHANTABILITY or FITNESS
|
|
FOR A PARTICULAR PURPOSE. See the GNU GPL for more details.
|
|
|
|
As additional permission under GNU GPL version 3 section 7, you
|
|
may distribute non-source (e.g., minimized or compacted) forms of
|
|
that code without the copy of the GNU GPL normally required by
|
|
section 4, provided you include this license notice and a URL
|
|
through which recipients can access the Corresponding Source.
|
|
|
|
|
|
@licend The above is the entire license notice
|
|
for the JavaScript code in this tag.
|
|
*/
|
|
<!--/*--><![CDATA[/*><!--*/
|
|
function CodeHighlightOn(elem, id)
|
|
{
|
|
var target = document.getElementById(id);
|
|
if(null != target) {
|
|
elem.cacheClassElem = elem.className;
|
|
elem.cacheClassTarget = target.className;
|
|
target.className = "code-highlighted";
|
|
elem.className = "code-highlighted";
|
|
}
|
|
}
|
|
function CodeHighlightOff(elem, id)
|
|
{
|
|
var target = document.getElementById(id);
|
|
if(elem.cacheClassElem)
|
|
elem.className = elem.cacheClassElem;
|
|
if(elem.cacheClassTarget)
|
|
target.className = elem.cacheClassTarget;
|
|
}
|
|
/*]]>*///-->
|
|
</script>
|
|
|
|
</head>
|
|
<body>
|
|
|
|
<div id="preamble">
|
|
|
|
</div>
|
|
|
|
<div id="content">
|
|
<h1 class="title">6502Arch</h1>
|
|
|
|
|
|
<div id="table-of-contents">
|
|
<h2>Table of Contents</h2>
|
|
<div id="text-table-of-contents">
|
|
<ul>
|
|
<li><a href="#sec-1">1 Addressing modes</a>
|
|
<ul>
|
|
<li><a href="#sec-1-1">1.1 Absolute</a></li>
|
|
<li><a href="#sec-1-2">1.2 Zero-page</a></li>
|
|
<li><a href="#sec-1-3">1.3 Zero-page, X</a></li>
|
|
<li><a href="#sec-1-4">1.4 Zero-page, Y</a></li>
|
|
<li><a href="#sec-1-5">1.5 Immediate</a></li>
|
|
<li><a href="#sec-1-6">1.6 Relative</a></li>
|
|
<li><a href="#sec-1-7">1.7 Implicit</a></li>
|
|
<li><a href="#sec-1-8">1.8 Indirect</a></li>
|
|
<li><a href="#sec-1-9">1.9 Indexed Indirect</a></li>
|
|
<li><a href="#sec-1-10">1.10 Indirect Indexed</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#sec-2">2 Stack</a></li>
|
|
<li><a href="#sec-3">3 Jumping</a></li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
|
|
<div id="outline-container-1" class="outline-2">
|
|
<h2 id="sec-1"><span class="section-number-2">1</span> Addressing modes</h2>
|
|
<div class="outline-text-2" id="text-1">
|
|
|
|
|
|
<p>
|
|
has a 16-byte address bus.
|
|
</p>
|
|
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-1" class="outline-3">
|
|
<h3 id="sec-1-1"><span class="section-number-3">1.1</span> Absolute</h3>
|
|
<div class="outline-text-3" id="text-1-1">
|
|
|
|
|
|
<ul>
|
|
<li>Full memory location specified, i.e. $c000
|
|
</li>
|
|
<li>65536 bytes of addressable memory (2<sup>16</sup> duyyy)
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-2" class="outline-3">
|
|
<h3 id="sec-1-2"><span class="section-number-3">1.2</span> Zero-page</h3>
|
|
<div class="outline-text-3" id="text-1-2">
|
|
|
|
|
|
<ul>
|
|
<li>1 byte adress, i.e. $c0, 256 bytes adressable
|
|
</li>
|
|
<li>faster, takes less program space
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-3" class="outline-3">
|
|
<h3 id="sec-1-3"><span class="section-number-3">1.3</span> Zero-page, X</h3>
|
|
<div class="outline-text-3" id="text-1-3">
|
|
|
|
|
|
<ul>
|
|
<li>Relative adressing <span style="text-decoration:underline;">within</span> the zero page.
|
|
</li>
|
|
<li>Adds the value in reg. x with a 1-byte adress
|
|
</li>
|
|
<li>i.e. STA $a0, X
|
|
</li>
|
|
<li>Address wraps around if the addition is larger than 1 byte
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-4" class="outline-3">
|
|
<h3 id="sec-1-4"><span class="section-number-3">1.4</span> Zero-page, Y</h3>
|
|
<div class="outline-text-3" id="text-1-4">
|
|
|
|
|
|
<ul>
|
|
<li>equiv to zero-page, X but can only be used with LDX and STX
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-5" class="outline-3">
|
|
<h3 id="sec-1-5"><span class="section-number-3">1.5</span> Immediate</h3>
|
|
<div class="outline-text-3" id="text-1-5">
|
|
|
|
|
|
<ul>
|
|
<li>i.e. #$c0
|
|
</li>
|
|
<li>loads immedate number into register
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-6" class="outline-3">
|
|
<h3 id="sec-1-6"><span class="section-number-3">1.6</span> Relative</h3>
|
|
<div class="outline-text-3" id="text-1-6">
|
|
|
|
|
|
<ul>
|
|
<li>i.e. $c0, or label
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-7" class="outline-3">
|
|
<h3 id="sec-1-7"><span class="section-number-3">1.7</span> Implicit</h3>
|
|
<div class="outline-text-3" id="text-1-7">
|
|
|
|
|
|
<ul>
|
|
<li>when operation doesn't deal with memory
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-8" class="outline-3">
|
|
<h3 id="sec-1-8"><span class="section-number-3">1.8</span> Indirect</h3>
|
|
<div class="outline-text-3" id="text-1-8">
|
|
|
|
|
|
<ul>
|
|
<li>Uses absolute address to get another address
|
|
</li>
|
|
<li>first address is LSB of address, following byte is MSB
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-9" class="outline-3">
|
|
<h3 id="sec-1-9"><span class="section-number-3">1.9</span> Indexed Indirect</h3>
|
|
<div class="outline-text-3" id="text-1-9">
|
|
|
|
|
|
<ul>
|
|
<li>i.e. LDA ($c0, X)
|
|
</li>
|
|
<li>Take a zero page adress and add the value in reg. x to it, look up 2 byte address
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-1-10" class="outline-3">
|
|
<h3 id="sec-1-10"><span class="section-number-3">1.10</span> Indirect Indexed</h3>
|
|
<div class="outline-text-3" id="text-1-10">
|
|
|
|
|
|
<ul>
|
|
<li>zero page address dereferenced then Y is added to it
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-2" class="outline-2">
|
|
<h2 id="sec-2"><span class="section-number-2">2</span> Stack</h2>
|
|
<div class="outline-text-2" id="text-2">
|
|
|
|
|
|
<ul>
|
|
<li>lives in memory between $0100 and $01ff
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div id="outline-container-3" class="outline-2">
|
|
<h2 id="sec-3"><span class="section-number-2">3</span> Jumping</h2>
|
|
<div class="outline-text-2" id="text-3">
|
|
|
|
|
|
<ul>
|
|
<li>JSR/RTS: Jump to subroutine and return from subroutine
|
|
</li>
|
|
</ul>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
</div>
|
|
|
|
<div id="postamble">
|
|
<p class="date">Date: 2014-09-25T21:09-0400</p>
|
|
<p class="author">Author: Alex Weisberger</p>
|
|
<p class="creator"><a href="http://orgmode.org">Org</a> version 7.9.3f with <a href="http://www.gnu.org/software/emacs/">Emacs</a> version 24</p>
|
|
<a href="http://validator.w3.org/check?uri=referer">Validate XHTML 1.0</a>
|
|
|
|
</div>
|
|
</body>
|
|
</html>
|