/*
#include "stm32f4_discovery.h"
#include "stm32f4xx_conf.h"
 

uint32_t Gb_TimingDelay;
void Delay(uint32_t nTime);

void main( )
{
    SysTick_Config(SystemCoreClock / 1000); //设置systemtick 一毫秒中断
    RCC->AHB1ENR |= 0x00000008; //使能GPIOD 时钟
    RCC->APB2ENR |= (1<<14); //使能syscfg 时钟
    GPIOD->MODER &= 0x00FFFFFF; //设置PD12,13,14,15 输出
    GPIOD->MODER |= 0x55000000;
    GPIOD->OTYPER &= 0xFFFF0FFF; //设置PD12,13,14,15 推挽输出
    GPIOD->OSPEEDR &= 0x00FFFFFF; //PD12,13,14,15 速度100m
    GPIOD->OSPEEDR |= 0xff000000;
    SYSCFG->CMPCR = 0x00000001; //使用IO 补偿单元，
    //当GPIO 速度超过50M 的时候要考虑使用此设置
    GPIOD->PUPDR &= 0x00FFFFFF; //PD12,13,14,15 无上拉无下拉
    GPIOD->BSRRH = 0xf000; //reset register GPIOx_BSRRH, write only
    //set register GPIOx_BSRRL, write only
    
    while(1)
    {
        GPIOD->BSRRH = 0xf000;
        GPIOD->BSRRL = 0x1000;
        Delay(100);
        GPIOD->BSRRH = 0xf000;
        GPIOD->BSRRL = 0x1000<<1;
        Delay(100);
        GPIOD->BSRRH = 0xf000;
        GPIOD->BSRRL = 0x1000<<2;
        Delay(100);
        GPIOD->BSRRH = 0xf000;
        GPIOD->BSRRL = 0x1000<<3;
        Delay(100);
    }
}

void Delay(uint32_t nTime)
{
    Gb_TimingDelay = nTime;
    while(Gb_TimingDelay != 0);
}
void SysTick_Handler(void)
{
    if (Gb_TimingDelay != 0x00)
    {
        Gb_TimingDelay--;
    }
}
*/

#include "stm32f4_discovery.h"
#include "stm32f4xx_conf.h"
  
uint32_t Gb_TimingDelay;
void Delay(uint32_t nTime);

void main( )
{
    SysTick_Config(SystemCoreClock / 1000); //设置systemtick 一毫秒中断
    
    /*
    //Initialize LEDs mounted on STM32F4-Discovery board 
    STM_EVAL_LEDInit(LED4);
    STM_EVAL_LEDInit(LED3);
    STM_EVAL_LEDInit(LED5);
    STM_EVAL_LEDInit(LED6);
      
    //Turn on LED4 and LED5 
    STM_EVAL_LEDOn(LED4);
    STM_EVAL_LEDOn(LED5);
    
    while(1)
    {
        //Toggle LED3 and LED6 
        STM_EVAL_LEDToggle(LED3);
        STM_EVAL_LEDToggle(LED6);

        //Insert a delay 
        Delay(100);

        //Toggle LED4 and LED5 
        STM_EVAL_LEDToggle(LED4);
        STM_EVAL_LEDToggle(LED5);

        //Insert a delay 
        Delay(100);     
    }
    */
    
    //-------------------------------------
    GPIO_InitTypeDef  GPIO_InitStructure;
  
    //Enable the GPIO_LED Clock 
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

    //Configure the GPIO_LED pin 
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOD, &GPIO_InitStructure);
    //点亮这个灯
    GPIOD->BSRRL = GPIO_Pin_12;
    
    while(1)
    {
        //  
        GPIOD->ODR ^= GPIO_Pin_12;
        //Insert a delay 
        Delay(100);     
    }
    
}

void Delay(uint32_t nTime)
{
    Gb_TimingDelay = nTime;
    while(Gb_TimingDelay != 0);
}
void SysTick_Handler(void)
{
    if (Gb_TimingDelay != 0x00)
    {
        Gb_TimingDelay--;
    }
}