文档上对GPIO如下介绍

General-purpose I/O (GPIO)
During and just after reset, the alternate functions are not active and the I/O ports are
configured in Input Floating mode (CNFx[1:0]=01b, MODEx[1:0]=00b).

我的IO上拉LED，一上电或者复位状态，LED点亮，与IO口低电平没啥区别，能否将IO口上电时默认改成高阻或者高电平呢？等配置完IO口后才正常工作。