code: def REV(self, params):
          
          Ra, Rb = self.get_two_parameters(self.TWO_PARAMETER_COMMA_SEPARATED, params)
  
          self.check_arguments(low_registers=(Ra, Rb))
  
          def REV_func():
              self.register[Ra] = ((self.register[Rb] & 0xFF000000) >> 24) | \
                                  ((self.register[Rb] & 0x00FF0000) >> 8) | \
                                  ((self.register[Rb] & 0x0000FF00) << 8) | \
                                  ((self.register[Rb] & 0x000000FF) << 24)
  
          return REV_func
docs: REV Ra, Rb
  
          Reverse the byte order in register Rb and store the result in Ra