刚才帮另外一个回答问题时候遇到了个内容,应该能解决你的困惑了,你可以去看库函数的gpio.h里面的内容,如下
/**
* [url=home.php?mod=space&uid=247401]@brief[/url] Disable I/O Digital Input Path
*
* @param[in] port GPIO port. It could be PA, PB, PC, PD, PE or PF.
* @param[in] u32PinMask The single or multiple pins of specified GPIO port.
* It could be BIT0 ~ BIT15 for PA and PB GPIO port.
* It could be BIT0 ~ BIT3, BIT6 ~ BIT11, BIT14 and BIT15 for PC GPIO port.
* It could be BIT6, BIT7, BIT14 and BIT15 for PD GPIO port.
* It could be BIT5 for PE GPIO port.
* It could be BIT0, BIT1 and BIT4 ~ BIT8 for PF GPIO port.
*
* [url=home.php?mod=space&uid=266161]@return[/url] None
*
* [url=home.php?mod=space&uid=1543424]@Details[/url] Disable I/O digital input path of specified GPIO pin.
*/
#define GPIO_DISABLE_DIGITAL_PATH(port, u32PinMask) ((port)->OFFD |= ((u32PinMask)<<16))
上面是关于如何关闭GPIO功能的,但是你看到没,不是所有的管脚是这样的,,,,所以你说的那几个特别的管脚,应该就是系统这样设计的。
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