Files
oldlinux-files/Ref-docs/manual Intel386/I386Manual/SMSW.HTM
2024-02-19 00:21:47 -05:00

51 lines
2.2 KiB
HTML

<html><!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html>
<head>
<title>80386 Programmer's Reference Manual -- Opcode SMSW</title>
</head>
<body>
<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>
<b>prev:</b><a href="SLDT.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/SLDT.HTM"> SLDT Store Local Descriptor Table Register</a><br>
<b>next:</b><a href="STC.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/STC.HTM"> STC Set Carry Flag</a>
<p>
<hr>
<p>
<h1>SMSW -- Store Machine Status Word</h1>
<pre>
Opcode Instruction Clocks Description
0F 01 /4 SMSW r/m16 2/3,pm=2/2 Store machine status word to EA
word
</pre>
<h2>Operation</h2>
<pre>
r/m16 := MSW;
</pre>
<h2>Description</h2>
SMSW stores the machine status word (part of CR0) in the two-byte register or memory location indicated by the effective address operand.
<h2>Flags Affected</h2>
None
<h2>Protected Mode Exceptions</h2>
#GP(0) if the result is in a nonwritable segment; #GP(0) for an illegal memory operand effective address in the CS, DS, ES, FS, or GS segments; #SS(0) for an illegal address in the SS segment; #PF(fault-code) for a page fault
<h2>Real Address Mode Exceptions</h2>
Interrupt 13 if any part of the operand would lie outside of the effective address space from 0 to 0FFFFH
<h2>Virtual 8086 Mode Exceptions</h2>
Same exceptions as in Real Address Mode; #PF(fault-code) for a page fault
<h2>Notes</h2>
This instruction is provided for compatibility with the 80286; 80386 programs should use <a href="MOVRS.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/MOVRS.HTM">MOV</a> ..., CR0.
<p>
<hr>
<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>
<b>prev:</b><a href="SLDT.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/SLDT.HTM"> SLDT Store Local Descriptor Table Register</a><br>
<b>next:</b><a href="STC.HTM" tppabs="http://webster.cs.ucr.edu/Page_TechDocs/Doc386/STC.HTM"> STC Set Carry Flag</a>
</body>