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Table e8. encoding of 32-bit address mode with “m – Intel 386 User Manual

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Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL

E-28

Table E-8. Encoding of 32-bit Address Mode with “mod r/m” Byte (No s-i-b Byte Present)

mod r/m

Effective Address

mod r/m

Effective Address

00 000
00 001
00 010
00 011
00 100
00 101
00 110

00 111

01 000
01 001
01 010
01 011
01 100
01 101
01 110

01 111

DS:[EAX]
DS:[ECX]
SS:[EDX]
SS:[EBX]

s-i-b is present

DS:[d32]
DS:[ESI]
DS:[EDI]

DS:[EAX + d8]
DS:[ECX + d8]
SS:[EDX + d8]
SS:[EBX + d8]

s-i-b is present

SS:[EBP + d8]

DS:[ESI + d8]
DS:[EDI + d8]

10 000
10 001
10 010

10 011

10 100
10 101

10 110
10 111

11 000
11 001
11 010
11 011
11 100
11 101
11 110

11 111

DS:[EAX + d32]
DS:[ECX + d32]
SS:[EDX + d32]
SS:[EBX + d32]

s-i-b is present

SS:[EBP + d32]

SS:[ESI + d32]

DS:[EDI + d32]

register - see tables below
register - see tables below
register - see tables below
register - see tables below
register - see tables below
register - see tables below
register - see tables below
register - see tables below

Register Specified by r/m

During 16-bit Data Operations

mod r/m

Function of w Field

(when w = 0)

(when w = 1)

11 000
11 001
11 010

11 011

11 100
11 101

11 110
11 111

AL
CL
DL
BL

AH
CH
DH
BH

AX
CX
DX
BX
SP
BP

SI
DI

Register Specified by r/m

During 32-bit Data Operations

mod r/m

Function of w Field

(when w = 0)

(when w = 1)

11 000
11 001
11 010

11 011

11 100
11 101

11 110
11 111

AL
CL
DL
BL

AH
CH
DH
BH

EAX
ECX
EDX
EBX
ESP
EBP

ESI
EDI