4、SPI的CS脚在配置软件中一般是有四根（CS0、CS1、CS2、CS3），一般而言我们只需要使用其中一根或者两根即可，那剩余的CS片选信号PIN脚如果配置成其他功能，是否会引起功能管脚冲突；Uart的流控信号（RTS、CTS）也有同样的问题，当我使用UART接口时，但是我不需要使用流控信号，对应的流控信号管脚可否配置为其他的功能管脚；
SPI's CS pins generally have four in the configuration software (CS0, CS1, CS2, CS3), generally speaking, we only need to use one or two of them, then the remaining CS chip select signal PIN pin if configured with other functions, whether it will cause function pin conflicts; Uart's fluidic signals (RTS, CTS) also have the same problem, when I use the UART interface, but I don't need to use the fluidic signal, can the corresponding fluidic signal pins be configured as other functional pins;
