IA186EM/IA188EM
Data Sheet
8-Bit/16-Bit Microcontrollers
February 25, 2011
7.1.3 Auxiliary Field
The Auxiliary Field is defined below.
aux If mod = 11 and word = 0 If mod = 11 and word = 1
000 AL
001 CL
010 DL
011 BL
100 AH
101 CH
110 DH
111 BH
AX
CX
DX
BX
SP
BP
SI
DI
Note: When mod 11, depends on instruction.
7.1.4 r/m Field
The r/m field is defined below.
r/m Description
000 EA = (BX) + (SI) + DISP [where EA is the Effective Address]
001 EA = (BX) + (DI) + DISP
010 EA = (BP) + (SI) + DISP
011 EA = (BX) + (DI) + DISP
100 EA = (SI) + DISP
101 EA = (DI) + DISP
110 EA = (BP) + DISP [except if mod = 00, then EA = disp-high:disp-low]
111 EA = (BX) + DISP
7.1.5 Displacement
The displacement is an 8- or 16-bit value added to the offset portion of the address.
7.1.6 Immediate Bytes
The immediate bytes consist of up to 16 bits of immediate data.
7.1.7 Segment Override Prefix
The segment override prefix is configured as shown below.
7
0
6
0
5
1
4
3
2
1
1
1
0
0
SR SR
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IA211050831-19
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