本程序已经调试通过，使用I2C来从外部时钟芯片中读取并写入时间。文档包含i2c的驱动程序、时钟芯片的读与写、以及使用定时器中断产生脉冲来模拟gps对时。-This procedure has been debugging through the use of I2C chip from the external clock time to read and write. Document contains the i2c driver, the clock read and write chip