def method_missing(method, *args, &block)
      super
    rescue NoMethodError
      return regs(method) if self.has_reg?(method)
      return ports(method) if self.has_port?(method)
      if method.to_s =~ /=$/
        define_singleton_method(method) do |val|
          instance_variable_set("@#{method.to_s.sub('=', '')}", val)
        end
      else
        define_singleton_method(method) do
          instance_variable_get("@#{method}")
        end
      end
      send(method, *args, &block)
    end
def method_missing(method, *args, &block)
      super
    rescue NoMethodError
      return regs(method) if self.has_reg?(method)
      return ports(method) if self.has_port?(method)
      if method.to_s =~ /=$/
        define_singleton_method(method) do |val|
          instance_variable_set("@#{method.to_s.sub('=', '')}", val)
        end
      else
        define_singleton_method(method) do
          instance_variable_get("@#{method}")
        end
      end
      send(method, *args, &block)
    end
Used to create attribute accessors on the fly.

 On first call of a missing method a method is generated to avoid the missing lookup
 next time, this should be faster for repeated lookups of the same method, e.g. reg