Intel 253666-024US User Manual

Page 589

Vol. 2A 3-543

INSTRUCTION SET REFERENCE, A-M

LGDT/LIDT—Load Global/Interrupt Descriptor Table Register

Real-Address Mode Exceptions

#UD

If source operand is not a memory location.
If the LOCK prefix is used.

#GP

If a memory operand effective address is outside the CS, DS,

ES, FS, or GS segment limit.

#SS

If a memory operand effective address is outside the SS

segment limit.

Virtual-8086 Mode Exceptions

#UD

If source operand is not a memory location.
If the LOCK prefix is used.

#GP(0)

The LGDT and LIDT instructions are not recognized in virtual-

8086 mode.

#GP

If the current privilege level is not 0.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

64-Bit Mode Exceptions

#SS(0)

If a memory address referencing the SS segment is in a non-

canonical form.

#GP(0)

If the current privilege level is not 0.
If the memory address is in a non-canonical form.

#UD

If source operand is not a memory location.
If the LOCK prefix is used.

#PF(fault-code)

If a page fault occurs.