50 lines
1.7 KiB
HTML
50 lines
1.7 KiB
HTML
<html><!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
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<html>
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<head>
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<title>80386 Programmer's Reference Manual -- Opcode CLD</title>
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</head>
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<body>
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<b>up:</b> <a href="C17.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/C17.HTM">Chapter 17 -- 80386 Instruction Set</a><br>
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<b>prev:</b><a href="CLC.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/CLC.HTM"> CLC Clear Carry Flag</a><br>
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<b>next:</b><a href="CLI.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/CLI.HTM"> CLI Clear Interrupt Flag</a>
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<p>
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<hr>
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<p>
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<h1>CLD -- Clear Direction Flag</h1>
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<pre>
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Opcode Instruction Clocks Description
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FC CLD 2 Clear direction flag; SI and DI
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will increment during string
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instructions
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</pre>
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<h2>Operation</h2>
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<pre>
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DF := 0;
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</pre>
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<h2>Description</h2>
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CLD clears the direction flag. No other flags or registers are affected. After CLD is executed, string operations will increment the index registers (SI and/or DI) that they use.
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<h2>Flags Affected</h2>
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DF := 0
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<h2>Protected Mode Exceptions</h2>
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None
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<h2>Real Address Mode Exceptions</h2>
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None
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<h2>Virtual 8086 Mode Exceptions</h2>
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None
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<p>
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<hr>
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<p><b>up:</b> <a href="C17.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/C17.HTM">Chapter 17 -- 80386 Instruction Set</a><br>
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<b>prev:</b><a href="CLC.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/CLC.HTM"> CLC Clear Carry Flag</a><br>
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<b>next:</b><a href="CLI.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/CLI.HTM"> CLI Clear Interrupt Flag</a>
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</body>
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