8086_instruction_set.html

嵌入式C++开发环境 模拟器 可以帮助你调试开发环境 提高工作效率

   JB  label1
   PRINT 'AL is not below 5'
   JMP exit
label1:
   PRINT 'AL is below 5'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JBE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JBE
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Below or Equal to second operand (as set by CMP instruction).
Unsigned.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if CF = 1 or ZF = 1 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 5
   CMP AL, 5
   JBE  label1
   PRINT 'AL is not below or equal to 5'
   JMP exit
label1:
   PRINT 'AL is below or equal to 5'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JC">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JC
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if Carry flag is set to 1.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if CF = 1 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 255
   ADD AL, 1
   JC  label1
   PRINT 'no carry.'
   JMP exit
label1:
   PRINT 'has carry.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JCXZ">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JCXZ
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if CX register is 0.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if CX = 0 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV CX, 0
   JCXZ label1
   PRINT 'CX is not zero.'
   JMP exit
label1:
   PRINT 'CX is zero.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JE
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Equal to second operand (as set by CMP instruction).
Signed/Unsigned.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if ZF = 1 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 5
   CMP AL, 5
   JE  label1
   PRINT 'AL is not equal to 5.'
   JMP exit
label1:
   PRINT 'AL is equal to 5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JG">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JG
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Greater then second operand (as set by CMP instruction).
Signed.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if (ZF = 0) and (SF = OF) then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 5
   CMP AL, -5
   JG  label1
   PRINT 'AL is not greater -5.'
   JMP exit
label1:
   PRINT 'AL is greater -5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JGE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JGE
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Greater or Equal to second operand (as set by CMP instruction).
Signed.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if SF = OF then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 2
   CMP AL, -5
   JGE  label1
   PRINT 'AL &lt; -5'
   JMP exit
label1:
   PRINT 'AL >= -5'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JL">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JL
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Less then second operand (as set by CMP instruction).
Signed.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if SF &lt;> OF then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, -2
   CMP AL, 5
   JL  label1
   PRINT 'AL >= 5.'
   JMP exit
label1:
   PRINT 'AL &lt; 5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JLE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JLE
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Less or Equal to second operand (as set by CMP instruction).
Signed.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if SF &lt;> OF or ZF = 1 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, -2
   CMP AL, 5
   JLE label1
   PRINT 'AL > 5.'
   JMP exit
label1:
   PRINT 'AL &lt;= 5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JMP">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JMP
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>
	label<BR>
	4-byte address<BR>
	</NOBR>
</FONT>
</TD>
<TD>

Unconditional Jump.
Transfers control to another part of the program.
<I>4-byte address</I> may be entered in this form:
<FONT FACE="Fixedsys">1234h:5678h</FONT>, first value is a segment second
value is an offset.<BR>

<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	always jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 5
   JMP label1    ; jump over 2 lines!
   PRINT 'Not Jumped!'
   MOV AL, 0
label1:
   PRINT 'Got Here!'
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNA">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNA
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Not Above second operand (as set by CMP instruction).
Unsigned.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if CF = 1 or ZF = 1 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 2
   CMP AL, 5
   JNA label1
   PRINT 'AL is above 5.'
   JMP exit
label1:
   PRINT 'AL is not above 5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNAE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNAE
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Not Above and Not Equal to second operand (as set by CMP instruction).
Unsigned.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if CF = 1 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 2
   CMP AL, 5
   JNAE label1
   PRINT 'AL >= 5.'
   JMP exit
label1:
   PRINT 'AL &lt; 5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNB">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNB
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Not Below second operand (as set by CMP instruction).
Unsigned.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if CF = 0 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 7
   CMP AL, 5
   JNB label1
   PRINT 'AL &lt; 5.'
   JMP exit
label1:
   PRINT 'AL >= 5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNBE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNBE
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Not Below and Not Equal to second operand (as set by CMP instruction).
Unsigned.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if (CF = 0) and (ZF = 0) then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 7
   CMP AL, 5
   JNBE label1
   PRINT 'AL &lt;= 5.'
   JMP exit
label1:
   PRINT 'AL > 5.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNC">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNC
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if Carry flag is set to 0.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if CF = 0 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 2
   ADD AL, 3
   JNC  label1
   PRINT 'has carry.'
   JMP exit
label1:
   PRINT 'no carry.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNE
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Not Equal to second operand (as set by CMP instruction).
Signed/Unsigned.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if ZF = 0 then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 2
   CMP AL, 3
   JNE  label1
   PRINT 'AL = 3.'
   JMP exit
label1:
   PRINT 'Al &lt;> 3.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNG">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNG
</FONT>
</TD>
<TD>
<FONT FACE="Fixedsys">
	<NOBR>label</NOBR>
</FONT>
</TD>
<TD>

Short Jump if first operand is Not Greater then second operand (as set by CMP instruction).
Signed.
<BR><BR>Algorithm:<BR><BR>
<FONT FACE="Fixedsys">
<UL>
	if (ZF = 1) and (SF &lt;> OF) then jump
</UL>
</FONT>
Example:<PRE><FONT FACE="Fixedsys">   include 'emu8086.inc'
   #make_COM#
   ORG 100h
   MOV AL, 2
   CMP AL, 3
   JNG  label1
   PRINT 'AL > 3.'
   JMP exit
label1:
   PRINT 'Al &lt;= 3.'
exit:
   RET</FONT></PRE>

<FONT FACE="Fixedsys">
<TABLE BORDER=1 NOSHADE>
<TR> <TD>C</TD> <TD>Z</TD> <TD>S</TD> <TD>O</TD> <TD>P</TD> <TD>A</TD> </TR>
<TR> <TD COLSPAN=6>unchanged</TD> </TR>
</TABLE>
</FONT>

			<A NAME="JNGE">&nbsp;</A>
</TD>
</TR>




<TR>
<TD>
<FONT FACE="Fixedsys">
JNGE