A.5.321 UMOV: User Move Data
UMOV r/m8,reg8 ; 0F 10 /r [386,UNDOC]
UMOV r/m16,reg16 ; o16 0F 11 /r [386,UNDOC]
UMOV r/m32,reg32 ; o32 0F 11 /r [386,UNDOC]
UMOV reg8,r/m8 ; 0F 12 /r [386,UNDOC]
UMOV reg16,r/m16 ; o16 0F 13 /r [386,UNDOC]
UMOV reg32,r/m32 ; o32 0F 13 /r [386,UNDOC]
This undocumented instruction is used by in-circuit emulators to
access user memory (as opposed to host memory). It is used just like
an ordinary memory/register or register/register MOV instruction, but
accesses user space.
This instruction is only available on some AMD and IBM 386 and 486
processors.