连线如下所示：
ST-LINK V2 <---------> STM32
SWDIO <-------------> DIO
GND <-------------------> GND
SWCLK <--------------> SCLK
3.3V <------------------> 3.3 V
连线如下所示：
ST-LINK V2 <---------> STM32
SWDIO <-------------> DIO
GND <-------------------> GND
SWCLK <--------------> SCLK
3.3V <------------------> 3.3 V
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