x86 Instruction Set Reference

CLTS - Clear Task-Switched Flag in CR0

Opcode Mnemonic Description
0F 06 CLTS Clears TS flag in CR0.
Description

Clears the task-switched (TS) flag in the CR0 register. This instruction is intended for use in operating-system procedures. It is a privileged instruction that can only be executed at a CPL of 0. It is allowed to be executed in real-address mode to allow initialization for protected mode.

CLTS: Clear Task-Switched Flag in CR0 (x86 Instruction Set Reference)
Operation 
CR0.TS = 0;
Flags affected

The TS flag in CR0 register is cleared.

Protected Mode Exceptions
#GP(0)If the current privilege level is not 0.
Real-Address Mode Exceptions
None.
Virtual-8086 Mode Exceptions
#GP(0)CLTS is not recognized in virtual-8086 mode.