80386 Programmer's Reference Manual -- Opcode STR
STR -- Store Task Register
r/m := task register;
DescriptionThe contents of the task register are copied to the two-byte register or memory location indicated by the effective address operand.
STR is used only in operating system software. It is not used in application programs.
Protected Mode Exceptions#GP(0) if the result is in a nonwritable segment; #GP(0) for an illegal memory operand effective address in the CS, DS, ES, FS, or GS segments; #SS(0) for an illegal address in the SS segment; #PF(fault-code) for a page fault
Real Address Mode ExceptionsInterrupt 6; STR is not recognized in Real Address Mode
Virtual 8086 Mode ExceptionsSame exceptions as in Real Address Mode
NotesThe operand-size attribute has no effect on this instruction.