Intel 210200-002 manual REF References REF For Instruction SET, Mod Field Bit Assignments

REF REFERENCES REF

FOR INSTRUCTION SET

"reg" Field Bit Assignments:

16-Bit (w = 1)		8-Bit (w = 0)		Segment
000	AX	000	AL	00	ES
001	CX	001	CL	01	CS
010	OX	010	OL	10	SS
011	BX	011	BL	11	OS
100	SP	100	AH
101	BP	101	CH
110	SI	110	OH
111	01	111	BH

"mod" Field Bit Assignments:

Imod xxx r/ml

mod Displacement

00 OISP = 0*, disp-Iow and disp-high are absent

01OISP = disp-Iow sign-extended to 16-bits, disp-high is absent

10OISP = disp-high: disp-Iow

11rIm is treated as a "reg" field

"r1m" Field Bit Assignments:

rim Operand Address

000(BX) + (SI) + OISP

001(BX) + (01) + OISP

010(BP) + (SI) + OISP

011(BP) + (01) + OISP

100(SI) + OISP

101(01) + OISP

110(BP) + OISP

111(BX) + OISP

OISP follows 2nd byte of instruction (before data if required). *except if mod = 00 and rIm = 110 then EA = disp-high: disp-Iow.

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