具有I2C总线功能，可以完成数据的串行和并行输入、输出-With the I2C bus functionality, you can complete the serial and parallel data input and output

PCA9555 vxworks下驱动，平台为S3C2440，该驱动注重效率，数据的传输和接收只用一个函数i2c_transfer，可以直接使用，编译平台为tornado2.2.1-Driver, PCA9555 vxworks platform S3C2440, the driver focus on the efficiency of the transmission and reception of data using only a function i2c_transfer can di