lowlevelinit.c

万利stm32开发板上的led例程

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// STM32的 外设初始化函数库
// netjob @2008-7-6
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#include "stm32f103-s.h"
#include "lowlevelinit.h"

//=========================================================================
//
//=========================================================================
void delay()
{
int i,j;
j=0;
for (i=0; i<0xfffff; i++) j++;  // 1,048,575
}
//=========================================================================
//  LD1=LED4=PC7(PWM) LD2=LED4=PC6(PWM)  LD3=LED2=PC5  LD4=LED1=PC4
//=========================================================================
void Led_RW_ON(char index)
{
  switch(index)
  {
  case 0:
        STM32_Gpioc_Regs->bsrr.bit.BR7 =1;// 1：清除对应的ODRy位为0  关LD1
        STM32_Gpioc_Regs->bsrr.bit.BS7 =1;// 1：设置对应的ODRy位为1  开LD1
    break;
  case 1:
        STM32_Gpioc_Regs->bsrr.bit.BR6 =1;// 1：清除对应的ODRy位为0  关LD2
        STM32_Gpioc_Regs->bsrr.bit.BS6 =1;// 1：设置对应的ODRy位为1  开LD2
    break;
  case 2:
        STM32_Gpioc_Regs->bsrr.bit.BR5 =1;// 1：清除对应的ODRy位为0  关LD3
        STM32_Gpioc_Regs->bsrr.bit.BS5 =1;// 1：设置对应的ODRy位为1  开LD3
    break;
  case 3:
        STM32_Gpioc_Regs->bsrr.bit.BR4 =1;// 1：清除对应的ODRy位为0  关LD4
        STM32_Gpioc_Regs->bsrr.bit.BS4 =1;// 1：设置对应的ODRy位为1  开LD4
    break;
  }
}//end sub
//=========================================================================
//
//=========================================================================
void Led_RW_OFF(char index)
{
  switch(index)
  {
  case 0:
        STM32_Gpioc_Regs->bsrr.bit.BS7 =1;// 1：设置对应的ODRy位为1  开LD1
        STM32_Gpioc_Regs->bsrr.bit.BR7 =1;// 1：清除对应的ODRy位为0  关LD1
    break;
  case 1:
        STM32_Gpioc_Regs->bsrr.bit.BS6 =1;// 1：设置对应的ODRy位为1  开LD2
        STM32_Gpioc_Regs->bsrr.bit.BR6 =1;// 1：清除对应的ODRy位为0  关LD2
    break;
  case 2:
        STM32_Gpioc_Regs->bsrr.bit.BS5 =1;// 1：设置对应的ODRy位为1  开LD3
        STM32_Gpioc_Regs->bsrr.bit.BR5 =1;// 1：清除对应的ODRy位为0  关LD3
    break;
  case 3:
        STM32_Gpioc_Regs->bsrr.bit.BS4 =1;// 1：设置对应的ODRy位为1  开LD4
        STM32_Gpioc_Regs->bsrr.bit.BR4 =1;// 1：清除对应的ODRy位为0  关LD4
    break;
  }

}//end sub
//=========================================================================
//         RCC_Configuration(void)
//=========================================================================
void STM32_RCC_Configuration(void)
{
	/* Disable APB2 Peripheral Reset */
        STM32_Rcc_Regs->apb2rstr.all=0x00000000;
        /* Disable APB1 Peripheral Reset */
        STM32_Rcc_Regs->apb1rstr.all=0x00000000;
         /* FLITF and SRAM Clock ON */
        STM32_Rcc_Regs->ahbenr.all= 0x00000014;
        /* Disable APB2 Peripheral Clock */
        STM32_Rcc_Regs->apb2enr.all=0x00000000;
        /* Disable APB2 Peripheral Clock */
        STM32_Rcc_Regs->apb1enr.all=0x00000000;

        STM32_Rcc_Regs->cr.bit.HSION=1;		// HSI振荡器开启
      /* Reset SW[1:0], HPRE[3:0], PPRE1[2:0], PPRE2[2:0], ADCPRE[1:0] and MCO[2:0] bits*/
        STM32_Rcc_Regs->cfgr.all&= 0xF8FF0000;

      /* Reset HSEON, CSSON and PLLON bits */
        STM32_Rcc_Regs->cr.all&= 0xFEF6FFFF;

      /* Reset HSEBYP bit */
       STM32_Rcc_Regs->cr.all&= 0xFFFBFFFF;

      /* Reset PLLSRC, PLLXTPRE, PLLMUL[3:0] and USBPRE bits */
        STM32_Rcc_Regs->cfgr.all&= 0xFF80FFFF;
      /* Disable all interrupts */
        STM32_Rcc_Regs->cr.all= 0x00000000;

        STM32_Rcc_Regs->cr.bit.HSEON=0;		// HSE振荡器开启关闭
	STM32_Rcc_Regs->cr.bit.HSEBYP=0;	// 外部高速时钟没有旁路
	STM32_Rcc_Regs->cr.bit.HSERDY=0;	// 外部高速时钟就绪标志清零
		
	STM32_Rcc_Regs->cr.bit.HSEON=1;		// 外部高速时钟使能	1：HSE振荡器开启
	
 	while( !(STM32_Rcc_Regs->cr.bit.HSERDY ) );//由硬件置1来指示外部时钟已经稳定。
 	
 	/* HCLK = SYSCLK＝72MHZ  :HLCK 提供给CPU, 内存和DMA 最大72MHZ  */
 	STM32_Rcc_Regs->cfgr.bit.HPRE=RCC_AHB_SYSCLK_DIV1_B;	//AHB预分频

	/* PCLK2 = HCLK/1=SYSCLK=72   PCLK2 提供给 APB2外设，最大72MHZ */
 	STM32_Rcc_Regs->cfgr.bit.PPRE2=RCC_APB2_HCLK_DIV1_B;	//高速APB预分频（APB2）
 	
 	/* PCLK1 = HCLK/2=SYSCLK/2=36   PCLK1提供给APB1外设，最大36MHZ */
 	STM32_Rcc_Regs->cfgr.bit.PPRE1=RCC_APB1_HCLK_DIV2_B;	//低速APB预分频（APB1）必须保证APB1时钟频率不超过36MHz

	
  	/* ADCCLK = PCLK2/6     ADC转换速率：72M/6 = 12MHZ  */
 	STM32_Rcc_Regs->cfgr.bit.ADCPRE=RCC_ADCPRE_PCLK2_DIV6_B;	
 	
 	/* Flash 2 wait state */
 	STM32_Flash_Regs->ACR.all&=((u32)0x00000038);	//清零某些位
 	STM32_Flash_Regs->ACR.bit.LATENCY=2;	
	STM32_Flash_Regs->ACR.bit.PRFTBE=1;		//预取缓冲区使能	

	/*  PLLCLK = 8MHz * 9 = 72MHZ ) */
 	STM32_Rcc_Regs->cfgr.bit.PLLXTPRE=0;	    //HSE分频器作为PLL输入  0：HSE不分频
 	STM32_Rcc_Regs->cfgr.bit.PLLSRC=1;	    //HSE时钟作为PLL输入时钟
 	STM32_Rcc_Regs->cfgr.bit.PLLMUL=RCC_PLL_9_B;	    //PLL倍频系数9

	/* Enable PLL */
	STM32_Rcc_Regs->cr.bit.PLLON=1;			// PLL使能	
	while( !(STM32_Rcc_Regs->cr.bit.PLLRDY ) );	// PLL时钟就绪标志	PLL锁定后由硬件置1

	 /* Select PLL as system clock source */
 	STM32_Rcc_Regs->cfgr.bit.SW=0;	
 	STM32_Rcc_Regs->cfgr.bit.SW=2;	    //RCC_SW_SYSCLK_PLL

	/* Wait till PLL is used as system clock source */	
 	while(STM32_Rcc_Regs->cfgr.bit.SWS!=2);	    //RCC_SWS_SYSCLK_PLL
			
	/* Enable GPIOA, GPIOB, GPIOC, GPIOD, GPIOE and AFIO clocks */
	STM32_Rcc_Regs->apb2enr.all |=(RCC_ADC1EN|RCC_AFIOEN|RCC_IOPAEN|RCC_IOPBEN|RCC_IOPCEN|RCC_IOPDEN|RCC_IOPEEN);
	
	/* TIM3 AND tim4 clocks enable */
	 STM32_Rcc_Regs->apb1enr.all |=(RCC_TIM3EN| RCC_CANEN|RCC_TIM4EN);		
} //end sub
//=========================================================================
//         GPIO_Configuration(void)
//=========================================================================
void STM32_GPIO_Configuration(void)
{
	
  	/* Configure PC.04 -- PC.11 as Output push-pull */
	// LED 灯
	STM32_Gpioc_Regs->crl.bit.CNF4=Output_push_pull;   // PC.04 推挽输出
	STM32_Gpioc_Regs->crl.bit.MODE4=Output_Mode_50mhz; // PC.04 输出模式，最大速度50MHz

	STM32_Gpioc_Regs->crl.bit.CNF5=Output_push_pull;   // PC.05 推挽输出
	STM32_Gpioc_Regs->crl.bit.MODE5=Output_Mode_50mhz; // PC.05 输出模式，最大速度50MHz

	STM32_Gpioc_Regs->crl.bit.CNF6=Output_push_pull;
	STM32_Gpioc_Regs->crl.bit.MODE6=Output_Mode_50mhz;

	STM32_Gpioc_Regs->crl.bit.CNF7=Output_push_pull;
	STM32_Gpioc_Regs->crl.bit.MODE7=Output_Mode_50mhz;
		
}//ENDSUB
//=========================================================================
//       Button_Config(void)
//  开发板上的4按键输入初始化
//=========================================================================
void STM32_Button_Config(void)
{
  	/* Enable GPIOD clock */
	STM32_Rcc_Regs->apb2enr.bit.IOPDEN=1;//IOPDEN：IO口D时钟使能	
  	/* Configure PD.03, PD.04 as output push-pull */
  	// 注意了 这里是推挽输出 而实在是浮空输入!
 	STM32_Gpiod_Regs->crl.bit.CNF3=Input_floating;	// PD.03 浮空输入
	STM32_Gpiod_Regs->crl.bit.MODE3=Input_Mode;	// PD.03 输入模式
 	STM32_Gpiod_Regs->crl.bit.CNF4=Input_floating;	// PD.04 浮空输入
	STM32_Gpiod_Regs->crl.bit.MODE4=Input_Mode;	// PD.04 输入模式
}
//=========================================================================
//         NVIC_Configuration(void)
//=========================================================================
void STM32_NVIC_Configuration(void)
{
  
#ifdef  VECT_TAB_RAM
  	/* Set the Vector Table base location at 0x20000000 */
  	STM32_Scb_Regs->ExceptionTableOffset.all=0x20000000;
#else  /* VECT_TAB_FLASH  */
	/* Set the Vector Table base location at 0x08000000 */
  	STM32_Scb_Regs->ExceptionTableOffset.all=0x08000000;
#endif

  	/* Configure the Priority Group to 2 bits */
  	STM32_Scb_Regs->AIRC.all= ((u32)0x05FA0000)|((u32)0x500); 
	 /* Configure the SysTick handler priority */
	 STM32_Scb_Regs->SystemPriority[11].all=2; 
}//end sub
//=========================================================================
//        STM32_Interrupt_Set(void)
//        开中断 定时器2中断
//=========================================================================
void STM32_Interrupt_Set(void)
{

	/* enabling interrupt  设置TIM2中断优先级，和开中断*/
	STM32_Nvic_Regs->Priority[28].all=0x80;
	STM32_Nvic_Regs->Enable[0].bit.INT28=1;   // 28 35 可设置 TIM2 TIM2全局中断 0x0000_00B0

}//END SUB

//=========================================================================
//	TIM_Configuration(void)
//      设置TIMER-2定时器 为计数溢出中断，10毫秒中断一次
//	TIM2、3、4的时钟源是 APB1 即是 PCLK1  ( APB1 对应 PCLK1 )
//	PCLK1 = APB1 = HCLK/2 = SYSCLK/2 = 36MHZ (36,000,000 HZ)
//      但是倍频器会自动倍2， 又倍频回72MHZ.
//=========================================================================

void STM32_TIM2_Configuration(void)
{
	//  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	//  TIM_OCInitTypeDef  TIM_OCInitStructure ;
  	
        //  TIM_DeInit( TIM4);//复位TIM4定时器  	
  	STM32_Rcc_Regs->apb1rstr.all |=  RCC_TIM2RST;
  	STM32_Rcc_Regs->apb1rstr.all &= ~RCC_TIM2RST;

        STM32_Rcc_Regs->apb1enr.all |=RCC_TIM2EN;		
  	  	  	
  	/* TIM2 configuration */
  	//TIM_TimeBaseStructure.TIM_Period = 1000;     
  	//TIM_TimeBaseStructure.TIM_Prescaler = 72;    
  	//TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; 
  	//TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 
  	//TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

	STM32_Tim2_Regs->arr.all=10000;  //  定时10毫秒 1MHZ/S 除 10,000 HZ
	STM32_Tim2_Regs->psc.all=72;	//  72分频
	STM32_Tim2_Regs->cr1.bit.CKD=0; //  时钟分频因子
	STM32_Tim2_Regs->cr1.bit.DIR=0; //  0：计数器向上计数

  	/* Clear TIM2 update pending flag[清除TIM2溢出中断标志] */
  	//TIM_ClearFlag(TIM2, TIM_FLAG_Update);
	STM32_Tim2_Regs->sr.bit.UIF=0;	//更新中断标记 由软件清0 ,例如当上溢或下溢时,软件对CNT重新初始化
	  	

  	/* Enable TIM2 Update interrupt [TIM2溢出中断允许]*/
  	//TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
  	STM32_Tim2_Regs->dier.bit.UIE=1;//	允许更新中断
  	
  	/* TIM2 enable counter [允许tim2计数]*/
  	//TIM_Cmd(TIM2, ENABLE);
  	STM32_Tim2_Regs->cr1.bit.CEN=1;//	开启计数器

        STM32_Tim2_Regs->egr.bit.UG=1; //触发一次事件中断。
        STM32_Tim2_Regs->sr.bit.UIF=0;
  	
} //end sub