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Intel 253666-024US User Manual

Page 379

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Vol. 2A 3-333

INSTRUCTION SET REFERENCE, A-M

FINIT/FNINIT—Initialize Floating-Point Unit

Operation

FPUControlWord ← 037FH;

FPUStatusWord ← 0;

FPUTagWord ← FFFFH;

FPUDataPointer ← 0;

FPUInstructionPointer ← 0;

FPULastInstructionOpcode ← 0;

FPU Flags Affected

C0, C1, C2, C3 set to 0.

Floating-Point Exceptions

None.

Protected Mode Exceptions

#NM

CR0.EM[bit 2] or CR0.TS[bit 3] = 1.

#MF

If there is a pending x87 FPU exception.

#UD

If the LOCK prefix is used.

Real-Address Mode Exceptions

Same exceptions as in protected mode.

Virtual-8086 Mode Exceptions

Same exceptions as in protected mode.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

64-Bit Mode Exceptions

Same exceptions as in protected mode.

See also other documents in the category Intel Hardware: