stm32f10x_rcc.c

STM32F103 IIC memory example program.

/******************** (C) COPYRIGHT 2007 STMicroelectronics ********************
* File Name          : stm32f10x_rcc.c
* Author             : MCD Application Team
* Date First Issued  : 09/29/2006
* Description        : This file provides all the RCC firmware functions.
********************************************************************************
* History:
* 05/21/2007: V0.3
* 04/02/2007: V0.2
* 02/05/2007: V0.1
* 09/29/2006: V0.01
********************************************************************************
* THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************/

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x_rcc.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* ------------ RCC registers bit address in the alias region ----------- */
#define RCC_OFFSET                (RCC_BASE - PERIPH_BASE)

/* --- CR Register ---*/
/* Alias word address of HSION bit */		/*映射别名区CR中HSI的bit*/
#define CR_OFFSET                 (RCC_OFFSET + 0x00)
#define HSION_BitNumber           0x00
#define CR_HSION_BB               (PERIPH_BB_BASE + (CR_OFFSET * 32) + (HSION_BitNumber * 4))

/* Alias word address of PLLON bit */
#define PLLON_BitNumber           0x18
#define CR_PLLON_BB               (PERIPH_BB_BASE + (CR_OFFSET * 32) + (PLLON_BitNumber * 4))

/* Alias word address of CSSON bit */	/*CSS时钟安全系统使能*/
#define CSSON_BitNumber           0x13
#define CR_CSSON_BB               (PERIPH_BB_BASE + (CR_OFFSET * 32) + (CSSON_BitNumber * 4))

/* --- CFGR Register ---*/
/* Alias word address of USBPRE bit */
#define CFGR_OFFSET               (RCC_OFFSET + 0x04)
#define USBPRE_BitNumber          0x16
#define CFGR_USBPRE_BB            (PERIPH_BB_BASE + (CFGR_OFFSET * 32) + (USBPRE_BitNumber * 4))

/* --- BDCR Register ---*/
/* Alias word address of RTCEN bit */
#define BDCR_OFFSET               (RCC_OFFSET + 0x20)
#define RTCEN_BitNumber           0x0F
#define BDCR_RTCEN_BB             (PERIPH_BB_BASE + (BDCR_OFFSET * 32) + (RTCEN_BitNumber * 4))

/* Alias word address of BDRST bit */
#define BDRST_BitNumber           0x10
#define BDCR_BDRST_BB             (PERIPH_BB_BASE + (BDCR_OFFSET * 32) + (BDRST_BitNumber * 4))

/* --- CSR Register ---*/
/* Alias word address of LSION bit */
#define CSR_OFFSET                (RCC_OFFSET + 0x24)
#define LSION_BitNumber           0x00
#define CSR_LSION_BB              (PERIPH_BB_BASE + (CSR_OFFSET * 32) + (LSION_BitNumber * 4))

/* ---------------------- RCC registers bit mask ------------------------ */
/* CR register bit mask */
#define CR_HSEBYP_Reset           ((u32)0xFFFBFFFF)
#define CR_HSEBYP_Set             ((u32)0x00040000)
#define CR_HSEON_Reset            ((u32)0xFFFEFFFF)
#define CR_HSEON_Set              ((u32)0x00010000)
#define CR_HSITRIM_Mask           ((u32)0xFFFFFF07)

/* CFGR register bit mask */
#define CFGR_PLL_Mask             ((u32)0xFFC0FFFF)  ？
#define CFGR_PLLMull_Mask         ((u32)0x003C0000)
#define CFGR_PLLSRC_Mask          ((u32)0x00010000)
#define CFGR_PLLXTPRE_Mask        ((u32)0x00020000)
#define CFGR_SWS_Mask             ((u32)0x0000000C)
#define CFGR_SW_Mask  		      ((u32)0xFFFFFFFC)
#define CFGR_HPRE_Reset_Mask      ((u32)0xFFFFFF0F)
#define CFGR_HPRE_Set_Mask        ((u32)0x000000F0)
#define CFGR_PPRE1_Reset_Mask     ((u32)0xFFFFF8FF)
#define CFGR_PPRE1_Set_Mask       ((u32)0x00000700)
#define CFGR_PPRE2_Reset_Mask     ((u32)0xFFFFC7FF)
#define CFGR_PPRE2_Set_Mask       ((u32)0x00003800)
#define CFGR_ADCPRE_Reset_Mask    ((u32)0xFFFF3FFF)
#define CFGR_ADCPRE_Set_Mask      ((u32)0x0000C000)
#define RCC_RTCCLKSource_Mask     ((u32)0xFFFFFCFF)		/*我自己加的*/

/* CSR register bit mask */
#define CSR_RMVF_Set              ((u32)0x01000000)		 /*清除复位标志 0：保持复位标志；1：清零复位标志。*/

/* RCC Flag Mask */
#define FLAG_Mask                 ((u8)0x1F)

/* Typical Value of the HSI in Hz */
#define HSI_Value                 ((u32)8000000)	/*内部高速时钟8MHz*/

/* BDCR register base address */
#define BDCR_BASE                 (PERIPH_BASE + BDCR_OFFSET)

/* Time out for HSE start up */
#define HSEStartUp_TimeOut        128

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
static uc8 APBAHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};	  /*我做了修改,the first 8bit is all set 0*/
static uc8 APBAHBPrescTable2[8]	= {0, 0, 0, 0, 1, 2, 3, 4};                   /*我新定义的数组，用来算PCLK */
static uc8 ADCPrescTable[4] = {2, 4, 6, 8};

/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/

/*******************************************************************************
* Function Name  : RCC_DeInit
* Description    : Deinitializes the RCC peripheral registers to their default
*                  reset values.
*                   - The HSITRIM[4:0] bits in RCC_CR register are not modified
*                     by this function.
*                   - The RCC_BDCR and RCC_CSR registers are not reset by this
*                     function.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void RCC_DeInit(void)
{
  /* Disable APB2 Peripheral Reset */
  RCC->APB2RSTR = 0x00000000;

  /* Disable APB1 Peripheral Reset */
  RCC->APB1RSTR = 0x00000000;

  /* FLITF and SRAM Clock ON */
  RCC->AHBENR = 0x00000014;

  /* Disable APB2 Peripheral Clock */
  RCC->APB2ENR = 0x00000000;

  /* Disable APB1 Peripheral Clock */
  RCC->APB1ENR = 0x00000000;

  /* Set HSION bit */
  RCC->CR |= (u32)0x00000001;

  /* Reset SW[1:0], HPRE[3:0], PPRE1[2:0], PPRE2[2:0], ADCPRE[1:0] and MCO[2:0] bits*/
  RCC->CFGR &= 0xF8FF0000;
  
  /* Reset HSEON, CSSON and PLLON bits */	 /*将HSEON，CSSON，PLLON清零*/
  RCC->CR &= 0xFEF6FFFF;

  /* Reset HSEBYP bit */
  RCC->CR &= 0xFFFBFFFF;

  /* Reset PLLSRC, PLLXTPRE, PLLMUL[3:0] and USBPRE bits */
  RCC->CFGR &= 0xFF80FFFF;

  /* Disable all interrupts */
  RCC->CIR = 0x00000000;		 /*将时钟中断寄存器中所有位清零*/
}

/*******************************************************************************
* Function Name  : RCC_HSEConfig
* Description    : Configures the External High Speed oscillator (HSE).
*                  HSE can not be stopped if it is used directly or through the 
*                  PLL as system clock.
* Input          : - RCC_HSE: specifies the new state of the HSE.
*                    This parameter can be one of the following values:
*                       - RCC_HSE_OFF: HSE oscillator OFF
*                       - RCC_HSE_ON: HSE oscillator ON
*                       - RCC_HSE_Bypass: HSE oscillator bypassed with external
*                         clock
* Output         : None
* Return         : None
*******************************************************************************/
void RCC_HSEConfig(u32 RCC_HSE)
{
  /* Check the parameters */
  assert(IS_RCC_HSE(RCC_HSE));

  /* Reset HSEON and HSEBYP bits before configuring the HSE ------------------*/
  /* Reset HSEON bit */
  RCC->CR &= CR_HSEON_Reset;	/*将HSEON清零*/

  /* Reset HSEBYP bit */
  RCC->CR &= CR_HSEBYP_Reset;

  /* Configure HSE (RCC_HSE_OFF is already covered by the code section above) */
  switch(RCC_HSE)
  {
    case RCC_HSE_ON:
      /* Set HSEON bit */
      RCC->CR |= CR_HSEON_Set;
      break;
      
    case RCC_HSE_Bypass:
      /* Set HSEBYP and HSEON bits */
      RCC->CR |= CR_HSEBYP_Set | CR_HSEON_Set;
      break;            
      
    default:
      break;      
  }
}

/*******************************************************************************
* Function Name  : RCC_WaitForHSEStartUp
* Description    : Waits for HSE start-up.
* Input          : None
* Output         : None
* Return         : An ErrorStatus enumuration value:
*                         - SUCCESS: HSE oscillator is stable and ready to use
*                         - ERROR: HSE oscillator not yet ready
******************************************************************************等待HSE启动，计数HSEstartup_timeout=128次*/
ErrorStatus RCC_WaitForHSEStartUp(void)
{
  vu32 StartUpCounter = 0;

  /* Wait till HSE is ready and if Time out is reached exit */
  while((RCC_GetFlagStatus(RCC_FLAG_HSERDY) == RESET) &&	  /*  check the HSERDY flag if be reset and the times of counter if up to 128*/ 
        (StartUpCounter != HSEStartUp_TimeOut))
  {
    StartUpCounter++;
  }
 
  if(RCC_GetFlagStatus(RCC_FLAG_HSERDY) != RESET)	   /*if HSERDY flag is not be reset, HSE is normally start up*/
  {
    return SUCCESS;
  }
  else
  {
    return ERROR;
  }
}

/*******************************************************************************
* Function Name  : RCC_AdjustHSICalibrationValue
* Description    : Adjusts the Internal High Speed oscillator (HSI) calibration
*                  value.
* Input          : - HSICalibrationValue: specifies the calibration trimming value.
*                    This parameter must be a number between 0 and 0x1F.
* Output         : None
* Return         : None
******************************************************************************This function describe how to adjust the HSIcalibrationvalue*/
void RCC_AdjustHSICalibrationValue(u8 HSICalibrationValue)		                    
{
  u32 tmpreg = 0;

  /* Check the parameters */
  assert(IS_RCC_CALIBRATION_VALUE(HSICalibrationValue));   ？/*检查输入HSICalibrationValue的值是否正确*/

  tmpreg = RCC->CR;

  /* Clear HSITRIM[7:3] bits 将该四位（内部时钟调整）清零*/
  tmpreg &= CR_HSITRIM_Mask;

  /* Set the HSITRIM[7:3] bits according to HSICalibrationValue value 把HSI的校准值赋予HSITRIM[7：3]*/
  tmpreg |= (u32)HSICalibrationValue << 3;		   /*0x0000001F<<3 */

  /* Store the new value */
  RCC->CR = tmpreg;
}

/*******************************************************************************
* Function Name  : RCC_HSICmd
* Description    : Enables or disables the Internal High Speed oscillator (HSI).
*                  HSI can not be stopped if it is used directly or through the 
*                  PLL as system clock.
* Input          : - NewState: new state of the HSI.
*                    This parameter can be: ENABLE or DISABLE.
* Output         : None
* Return         : None
******************************************************************************将HSI使能或禁能，可以直接禁能，也可以用PLL做为系统
时钟将其禁能*/
void RCC_HSICmd(FunctionalState NewState)
{
  /* Check the parameters */
  assert(IS_FUNCTIONAL_STATE(NewState));