Stack Operation - Intel iAPX 86/88 User Manual

EXISTING
STACK
~
I
1062 00 11
1060 22 33
'"
105E 44
55
:1;0
0«
105B 66
77
~~
~(I)
105A 88 99
0'"
0>0
TOS
:...::..::-. 1058 AA BB
1056 01 23
r
~O
1054 45 67
~~
ffl(l)
1052 89 AB
a:w
a..:I:
r
1050; CD; EF
~~
10 50 , SS
00
I
08
I
SP
8086/8088 CPU
PUSH AX
AX'12134
1-1
1062 00 11
I
1060
22 33
I
105E 44 55
I
105B 66 77
105A 88 99
I
1058 AA BB
f.J
~1056
34 12
1054 45 67
1052 89 AB
r
1050; CD; EF
10 50 'SS
00 061 SP
STACK OPERATION FOR CODE SEQUENCE
PUSH AX
POPAX
POPBX
Figure 1·14 Stack Operation
POPAX
POPBX
AX '12
I
34
1-,
BX' BB
I
AA
' - 1
I
I
I
I
1062
00 11
1060 22 33
I
I
I
lOSE 44
55
I
I
105C 66
77 I
~105A
I
88
99
J
I
105B AA BB
1056 34 12
_--1
1054 45 67
1052 89
AB
r
1050; CD; EF
10 50 , SS
00
I
OA
I
SP
affect the performance of 8088, locating 16-bit data on
even addresses will insure maximum throughput if the
system is ever transferred to an 8086.
1.2.2 Software Overview
The 8086 and 8088 execute exactly the same instructions.
This instruction set includes equivalents to the instruc-
tions typically found in previous microprocessors, such as
the 8080/8085. Significant new operations include:
FFFFFH
RESERVED
FFFFCH
FFFFBH
DEDICATED
FFFFOH
FFFEFH
OPEN
.,
I
,
BOH
7FH
RESERVED
14H
13H
DEDICATED
OH
MEMORY
[FFH
OPEN
100H
RESERVED
FFH
FBH
F7H
OPEN
OH
liD
• multiplication and division of signed and unsigned bi-
nary numbers as well as unpacked decimal numbers,
• move, scan and compare operations for strings up to
64k bytes in length,
• non-destructive bit testing,
• byte translation from one code to another,
• software generated interrupts,
• a group of instructions that can help coordinate the
activities of multiprocessing systems.
The following paragraphs provide a description of the in-
structions by category and a detailed discussion of the
various operand addressing modes. In addition, a com-
plete instruction set summary is provided in tabular form
which recaps each device instruction by category, and
provides timing cycles for each instruction. Information
is also described on how to encode and decode machine
Figure 1·15 Reserved Memory and 110 Locations
instructions for any given assembly code instructioh.
1-12
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