对GPIO进行的解释，是外设的通用的输入输出功能-Carried out on the GPIO explanation is a common peripheral input and output functions

9534 芯片介绍。用于图像处理 主用用处车载单片机-The PCA9534 is a 16-pin CMOS device that provide 8 bits of General Purpose parallel 2 Input/Output (GPIO) expansion for I C-bus/SMB