hw/i386.reference/s14_02.htm

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   4 <TITLE>80386 Programmer's Reference Manual -- Section 14.2</TITLE>
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   7 <B>up:</B> <A HREF="c14.htm">
   8 Chapter 14 -- 80386 Real-Address Mode</A><BR>
   9 <B>prev:</B> <A HREF="s14_01.htm">14.1  Physical Address Formation</A><BR>
  10 <B>next:</B> <A HREF="s14_03.htm">14.3  Interrupt and Exception Handling</A>
  11 <P>
  12 <HR>
  13 <P>
  14 <H1>14.2  Registers and Instructions</H1>
  15 The register set available in real-address mode includes all the registers
  16 defined for the 8086 plus the new registers introduced by the 80386: FS, GS,
  17 debug registers, control registers, and test registers. New instructions
  18 that explicitly operate on the segment registers FS and GS are available,
  19 and the new segment-override prefixes can be used to cause instructions to
  20 utilize FS and GS for address calculations. Instructions can utilize 32-bit
  21 operands through the use of the operand size prefix.
  22 <P>
  23 The instruction codes that cause undefined opcode traps (interrupt 6)
  24 include instructions of the protected mode that manipulate or interrogate
  25 80386 selectors and descriptors; namely,
  26 <A HREF="VERR.htm">VERR</A>,
  27 <A HREF="VERR.htm">VERW</A>,
  28 <A HREF="LAR.htm">LAR</A>,
  29 <A HREF="LSL.htm">LSL</A>,
  30 <A HREF="LTR.htm">LTR</A>,
  31 <A HREF="STR.htm">STR</A>,
  32 <A HREF="LLDT.htm">LLDT</A>, and
  33 <A HREF="SLDT.htm">SLDT</A>.
  34 Programs executing in real-address mode are able to take
  35 advantage of the new applications-oriented instructions added to the
  36 architecture by the introduction of the 80186/80188, 80286 and 80386:
  37 <UL>
  38 <LI> New instructions introduced by 80186/80188 and 80286.
  39 <UL>
  40 <LI> <A HREF="PUSH.htm">PUSH</A> immediate data
  41 <LI> Push all and pop all (<A HREF="PUSHA.htm">PUSHA</A> and
  42 <A HREF="POPA.htm">POPA</A>)
  43 <LI> Multiply immediate data
  44 <LI> Shift and rotate by immediate count
  45 <LI> String I/O
  46 <LI> <A HREF="ENTER.htm">ENTER</A> and
  47 <A HREF="LEAVE.htm">LEAVE</A>
  48 <LI> <A HREF="BOUND.htm">BOUND</A>
  49 </UL>
  50 <LI> New instructions introduced by 80386.
  51 <UL>
  52 <LI> <A HREF="LGS.htm">LSS</A>,
  53 <A HREF="LGS.htm">LFS</A>,
  54 <A HREF="LGS.htm">LGS</A> instructions
  55 <LI> Long-displacement conditional jumps
  56 <LI> Single-bit instructions
  57 <LI> Bit scan
  58 <LI> Double-shift instructions
  59 <LI> Byte set on condition
  60 <LI> Move with sign/zero extension
  61 <LI> Generalized multiply
  62 <LI> <A HREF="MOVRS.htm">MOV</A> to and from control registers
  63 <LI> <A HREF="MOVRS.htm">MOV</A> to and from test registers
  64 <LI> <A HREF="MOVRS.htm">MOV</A> to and from debug registers
  65 </UL>
  66 </UL>
  67 <P>
  68 <HR>
  69 <P>
  70 <B>up:</B> <A HREF="c14.htm">
  71 Chapter 14 -- 80386 Real-Address Mode</A><BR>
  72 <B>prev:</B> <A HREF="s14_01.htm">14.1  Physical Address Formation</A><BR>
  73 <B>next:</B> <A HREF="s14_03.htm">14.3  Interrupt and Exception Handling</A>
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