I2C串行总线具有占用I/O口少，控制方式简单，信号传输速度快，配套功能芯片种类多的优点，非常适用于单片机系统设计中，I2C串行总线由两根线构成：数据线（SDA），时钟线（SCL）,其数据传输过程在很多书中都有介绍，这里不做专门说明。下面以24CXX系列SEEPROM为例介绍EM78系列单片机如何设计I2C总线接口。-I2C serial bus with the occupation of I/O port less control is simple, signal transmission speed, matching the types of multi-functional chip merits, is ideal for single-chip system design, I2C serial bus constituted by two lines : data line (SDA), the clock line (SCL), its data transmission process of the book are introduced in many here do not specifically indicate. 24Cxx series SEEPROM the following as an example to introduce how to design EM78 series single-chip I2C bus interface.