各位大神求帮忙看一下为毛我这个GPIOF口没办法输出高电平，谢谢啦！！
RCC_APB2_START |= RCC_REGISTER_IOF;
#define RCC_APB2_START (*(volatile unsigned int *)0x40021018)
#define RCC_REGISTER_IOF 0x00000080
#define GPIOF_START (*(volatile unsigned int *)0x40011c00)
#define GPIOF_CRL (*(volatile unsigned int *)(GPIOF_START+0x0))
#define GPIOF_CRH (*(volatile unsigned int *)(GPIOF_START+0x04))
#define GPIOF_OUTPUTDATA (*(volatile unsigned int *)(GPIOF_START+0x0c))
GPIOF_CRH = 0x33333333;
GPIOF_CRL = 0x33333333;
GPIOF_OUTPUTDATA=0xffffffff;
------解决思路----------------------
口的输入输出方向没有定义吧