x86 Assembly Language Reference Manual

Clear Task-Switched (clts)


0 -> TS Flag in CR0


The task-switched flag in register CR0 is cleared by clta. The TS Flag is set by the 80386 for each task switch. The TS Flag is used as follows:

If a task switch is made after an ESC instruction is started, save the processor extension context before a new ESC instruction can be run. The fault handler resets the TS Flag and saves the context.

clts is not used in application program, it is used in operating systems.

clts can only be executed at privilege level 0.


Clear the TS flag: