一、步骤
1.使能I0口时钟。配置相关寄存器寄存器RCC->AHB1ENR
2.初始化IO口模式。配置四个配置寄存器
GPIOx_MODER/GPIOx_OTYPER/GPIOx_OSPEEDR/GPIOx_PUPDR
3.操作I0口，输出高低电平。配置寄存器GPIOX_ ODR或者BSRRL/BSRRH。
二、配置RCC->AHB1ENR
#include "led.h" #include "stm32f4xx.h" void LED_Init(void) { RCC->AHB1ENR|= 1<<5; //将第五位设置为1其余不变 //PF9 //PF10 }
三、配置IO口模式
红框区域配置为01，其余位置不变
先清零，再置1
//清零：要18、19位为00，取反为11，即3左移2*9 GPIOF->MODER &= ~(3<<2*9); //18位赋值为1，结合上述则为01 GPIOF->MODER |= 1<<(2*9);
配置成50MHz，为10
GPIOF->OSPEEDR &= ~(3<<2*9); GPIOF->OSPEEDR |= 2<<(2*9);
设置为01上拉
GPIOF->PUPDR &= ~(3<<2*9); GPIOF->PUPDR |= 1<<(2*9);
GPIOF->OTYPER &= ~(1<<9);//一个位配置一个寄存器 GPIOF->OTYPER |= 0<<9;
就是输出
四、代码展示
4.1 main.c
#include "stm32f4xx.h" #include "led.h" #include "delay.h" int main(void) { delay_init(168); LED_Init(); while(1){ GPIOF->ODR &= ~(1<<9); GPIOF->ODR &= ~(1<<10); delay_ms(500); GPIOF->ODR |= 1<<9; GPIOF->ODR |= 1<<10; delay_ms(1000); } }
4.2 led.c
#include "led.h" #include "stm32f4xx.h" void LED_Init(void) { RCC->AHB1ENR|= 1<<5; //将第五位设置为1其余不变 //PF9 //清零：要18、19位为00，取反为11，即3左移2*9 GPIOF->MODER &= ~(3<<2*9); //18位赋值为1，结合上述则为01 GPIOF->MODER |= 1<<(2*9); GPIOF->OSPEEDR &= ~(3<<2*9); GPIOF->OSPEEDR |= 2<<(2*9); GPIOF->PUPDR &= ~(3<<2*9); GPIOF->PUPDR |= 1<<(2*9); GPIOF->OTYPER &= ~(1<<9);//一个位配置一个寄存器 GPIOF->OTYPER |= 0<<9; GPIOF->ODR |= 1<<9;//1 //GPIOF->ODR &= ~(1<<9); //PF10 GPIOF->MODER &= ~(3<<2*10); GPIOF->MODER |= 1<<(2*10); GPIOF->OSPEEDR &= ~(3<<2*10); GPIOF->OSPEEDR |= 2<<(2*10); GPIOF->PUPDR &= ~(3<<2*10); GPIOF->PUPDR |= 1<<(2*10); GPIOF->OTYPER &= ~(1<<10);//一个位配置一个寄存器 GPIOF->OTYPER |= 0<<10; GPIOF->ODR |= 1<<10;//1 输出 }
4.3 led.h
#ifndef __LED_H_ #define __LED_H_ void LED_Init(void); #endif
