windows ce 平台上扩展串口驱动，使用芯片vk3214，同vk3222程序可相互移植。串口扩串口可用于低速领域，高速就需要用spi2serial或i2cToserial-windows ce platform expansion serial driver, use the chips vk3214, with vk3222 procedures and Transplantation. Expansion of low-speed serial port can be used in