ARPL              Adjust Privilege Level (286/386)   Flags: O D I T S Z A P C
                                                                      *
ARPL destination, source

       Logic:      if destination Privilege Level < source Privilege Level
                       destination Privilege Level . source Privilege Level
                       ZF . 1
                   else
                       ZF . 0

     This instruction checks to make sure that the destination Requested
     Privileged Level (RPL) is less than the source RPL. If it is, ARPL sets
     the destination RPL equal to the source RPL. Both destination and source
     must be valid selectors; source should be a 16-bit register.

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   Operands                   Clocks   Transfers  Bytes  Example
   ARPL register, register    10 (286)     -        2    ARPL AX,CX
   ARPL memory, register      11 (286)     -        2    ARPL MEM_RPL,CX
  --------------------------------------------------------------------------

        Note:          This instruction is only available in privileged
                       mode.