AngoLinux

80386 Programmer's Reference Manual -- Opcode SMSW

SMSW -- Store Machine Status Word

Opcode	Instruction	Clocks	Description	Example
0F 01 /4	smsww r/m16	2/3,pm=2/2	Store machine status word to EA word	`smsww %cx smsww (%ebx,1) smsww (%ebx,2) smsww (%ebx,%ebp,1)`

Operation




r/m16 := MSW;

Description

SMSW stores the machine status word (part of CR0) in the two-byte register or memory location indicated by the effective address operand.

Flags Affected

None

Protected Mode Exceptions

#GP(0) if the result is in a nonwritable segment; #GP(0) for an illegal memory operand effective address in the CS, DS, ES, FS, or GS segments; #SS(0) for an illegal address in the SS segment; #PF(fault-code) for a page fault

Real Address Mode Exceptions

Interrupt 13 if any part of the operand would lie outside of the effective address space from 0 to 0FFFFH

Virtual 8086 Mode Exceptions

Same exceptions as in Real Address Mode; #PF(fault-code) for a page fault

Notes

This instruction is provided for compatibility with the 80286; 80386 programs should use MOV ..., CR0.

[Home Page dell'ITIS "Fermi"] [80386 Programmer's Reference Manual Index] [Previous] [Next]