code: def MRS(self, params):
          
          Rj, Rspecial = self.get_two_parameters(self.TWO_PARAMETER_COMMA_SEPARATED, params)
  
          self.check_arguments(LR_or_general_purpose_registers=(Rj,), special_registers=(Rspecial,))
  
          def MRS_func():
              # TODO add combination registers IEPSR, IAPSR, and EAPSR
              # TODO needs to use APSR, IPSR, EPSR, IEPSR, IAPSR, EAPSR, PSR, MSP, PSP, PRIMASK, or CONTROL.
              # http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0553a/CHDBIBGJ.html
              if Rspecial == 'PSR':
                  self.register[Rj] = self.register['APSR'] | self.register['IPSR'] | self.register['EPSR']
              else:
                  self.register[Rj] = self.register[Rspecial]
  
          return MRS_func
docs: MRS Rj, Rspecial
  
          Copy the value of Rspecial to Rj
          Rspecial can be APSR, IPSR, or EPSR