First 8086 Program

1
First 8086 Program

• Module M14.4
• Section 9.4
• Appendix A (pp. 529-531)

2
A First 8086 Program
3
Table A2.a
Opcode Map
4
Table A2.a
Opcode Map
5
Table A2.a
Opcode Map
mov ax,1234h
B8 34 12
6
Table A2.a
Opcode Map
mov bx,ax
8B D8
7
Postbyte
Table A.4
Postbyte
reg
Field

reg
byte (b)
word (w)
000
AL
AX
001
CL
CX
010
DL
DX
011
BL
BX
100
AH
SP
100
AH
SP
SI
SI disp8
SI disp16
101
CH
BP
101
CH
BP
DI
DI disp8
DI disp16
110
DH
SI
110
DH
SI
Direct
BP disp8
BP disp16
111
BH
DI
111
BH
DI
BX
BX disp8
BX disp16
0 1 1
1 1
0 0 0
D8
mod
reg
r/m
mov bx,ax 8B D8
mov bx,ax mov w reg,r/m
reg bx 011
mod 11 r/m ax 0 0 0
8
A First 8086 Program
9
Table A2.a
Opcode Map
10
(No Transcript)
11
D8
011
11
000
neg ax
F7
D8
12
add ax,bx 03
Table A2.a
Opcode Map
13
Postbyte
Table A.4
Postbyte
reg
Field

reg
byte (b)
word (w)
000
AL
AX
001
CL
CX
010
DL
DX
011
BL
BX
100
AH
SP
100
AH
SP
SI
SI disp8
SI disp16
101
CH
BP
101
CH
BP
DI
DI disp8
DI disp16
110
DH
SI
110
DH
SI
Direct
BP disp8
BP disp16
111
BH
DI
111
BH
DI
BX
BX disp8
BX disp16
0 0 0
1 1
0 1 1
C3
mod
reg
r/m
add ax,bx 03 C3
add ax,bx add w reg,r/m
reg ax 000
mod 11 r/m bx 0 11
14
D3
010
11
011
not bx
F7
D3
15
A First 8086 Program
16
(No Transcript)