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INSTRUCTION SET REFERENCE
HLT—Halt
Description
This instruction stops instruction execution and places the processor in a HALT state. An
enabled interrupt, NMI, or a reset will resume execution. If an interrupt (including NMI) is used
to resume execution after a HLT instruction, the saved instruction pointer (CS:EIP) points to the
instruction following the HLT instruction.
The HLT instruction is a privileged instruction. When the processor is running in protected or
virtual-8086 mode, the privilege level of a program or procedure must be 0 to execute the HLT
instruction.
Operation
Enter Halt state;
Flags Affected
None.
Protected Mode Exceptions
#GP(0)
If the current privilege level is not 0.
Real-Address Mode Exceptions
None.
Virtual-8086 Mode Exceptions
#GP(0)
If the current privilege level is not 0.
Opcode
Instruction
Description
F4
HLT
Halt
