code: def STM(self, params):
          
          # TODO what registers can be stored?
          Ra, RLoList = self.get_two_parameters(r'\s*([^\s,]*)!,\s*{(.*)}(.*)', params).split(',')
          RLoList = RLoList.split(',')
          RLoList = [i.strip() for i in RLoList]
  
          self.check_arguments(low_registers=[Ra] + RLoList)
  
          def STM_func():
              for i in range(len(RLoList)):
                  for j in range(4):
                      self.memory[self.register[Ra] + 4*i + j] = ((self.register[RLoList[i]] >> (8 * j)) & 0xFF)
              self.register[Ra] += 4*len(RLoList)
  
          return STM_func
docs: STM Ra!, {RLoList}
  
          Store multiple registers into memory