采用UART方式0与LM74通信。 用C8051f020的P0.7作片选，主机通过TXD发送时钟信号，实现同步通信,半双工.RXD 作双向数据线.用六位

代码说明：

采用UART方式0与LM74通信。 用C8051f020的P0.7作片选，主机通过TXD发送时钟信号，实现同步通信,半双工.RXD 作双向数据线.用六位数码管显示LM74采集的温度值-The use of UART communication mode 0 and LM74. P0.7 used for the C8051F020 chip select, host TXD sent through the clock signal, to achieve synchronous communication, half-duplex. RXD for bi-directional data line. With six digital tube display LM74 temperature collected