GM814X SPI 接口为从机方式，各子串口的工作波特率、数据帧长等各种通信设置都可由软件设置，减少了外部MCU 的IO 需求。芯片的功耗低，具备多种掉电操作,该芯片的外部控制少，应用灵活，编程使用简单，适合于大多数多串口扩展需要的应用。

驱动源代码-GM814X SPI interface for the slave mode, the son of the work of the serial baud rate, data communications and other帧长settings can be set by software, reducing the demand for external MCU of IO. Chip, low power consumption with multiple power-down operation, the chip less external control, application flexibility, programming using a simple, suitable for most multi-serial port expansion needs of the application. Driver source code