飞思卡尔单片机DZ60---时钟初始化

最新推荐文章于 2024-11-07 12:49:14 发布

crazyvoice

最新推荐文章于 2024-11-07 12:49:14 发布

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分类专栏： MCU

本文链接：https://blog.youkuaiyun.com/crazyvoice/article/details/9418503

/* Derivative peripheral declarations */   
#include "derivative.h"     
   
/* Definitions and function prototypes */   
#include "DZ60_init.h"    

//FEI切换到PEE模式，外部晶振=4MHZ，总线频率=8MHZ（	中文手册,P144页）
/* External crystal oscillator = 4MHz */ 
/* FOR PEE mode: 
Bus_Clock = (1/2)*[(Osc_clock/Ref_div)*VCO_div]/(Bus_div) = 8MHz */ 

#define BUS_DIV 0       /* Bus divider = 0, divide by 1 */ 
#define REF_DIV 2       /* Reference divider = 2, divide by 4 */           
#define VCO_DIV 4       /* VCO divider = 4, multiply by 16 */ 


void MCG_Init(void) 
{
   SOPT1_COPT = 0;
  
//1
   //a)
    MCGC2_BDIV    = BUS_DIV; //0
    MCGC2_RANGE   = 1;
    MCGC2_HGO     = 1;
    MCGC2_EREFS   = 1;
    MCGC2_ERCLKEN = 1;
    
    //b)
    while(!MCGSC_OSCINIT); //循环检测，表明EREFS选择的晶体已经完成初始化
    
    //c)
    MCGC1_CLKS = 0X02;
    MCGC1_RDIV = 0X07;
    MCGC1_IREFS = 0;
    
    //d)
    while( MCGSC_IREFST );
    
    //e)
    while( (MC