i use nucleo-f446ze learning how to use STM32F4 stdperiph，but in STM32F4XX_GPIO.h，GPIO_MODE only have 4 mode，GPIO_Mode_IN = 0x00, /*!< GPIO Input Mode */GPIO_Mode_OUT = 0x01, /*!< GPIO Output Mode */GPIO_Mode_AF = 0x02, /*!< GPIO Alternate function M...