msp430f55××系列的的官方例程，包括普通的GPIO,看门狗定时器，ADC12,USB,通用串口，IIC，SPI，DMA,MPU等的操作-msp430f55 ×× series of official routines, including ordinary GPIO, watchdog timer, ADC12, USB, universal serial ports, IIC, SPI, DMA, MPU and other operations