Clear Task-Switched Flag in CR0

Encoding

Description

The CLTS instruction clears (resets) the task-switched flag in CR0.

CR0.TS is a flag that is set whenever a task switch occurs, and is used to synchronize the saving of the FPU context in multitasking environments.

This instruction can only be executed when CPL is 0 (i.e. ring 0). Attempts to execute this instruction in less privileged rings will cause a #UD exception to be raised.

Operation

public void CLTS()
{
    CR0.TS = 0;
}

Flags Affected

Exceptions

Real-Address Mode

Virtual-8086 Mode

Protected Mode

Compatibility Mode

Long Mode