STM32的JTAG / SWD接口是通过20PIN连接线连接目标板，所以ST-LINK/V2连接至STM32目标板时需要注意连接方向(The JTAG / SWD interface of STM32 connects the target board through the 20PIN connection line, so the connection direction needs to be noticed when ST-LINK/V2 is connected to the STM