详细介绍PIC单片机使用SPI方式与IC卡进行数据传输的原理和电路设计，以及使用USART方式与PC机进行串行异步通信的工作原理；介绍PIC单片机听SPI方式和USART方式的设置方法。-PIC detailed the use of SPI with Single-chip IC card for data transmission principles and circuit design, as well as with the PC using USART serial asynchronous communication for conducting the working principle　to listen to introduce single-chip microcomputer PIC mode and SPI mode USART Ways settings.