The midbit transition serves as a clocking mechanism and also a data: a low-to-high transition represents a 1, and a high-to-low transition represents a 0.

• 这种中间处的跳变既含有时钟信息，也含有数据信息：从低到高的跳变代表1，从高到低的跳变代表0(注意有些系统也可能相反)。