#include "Rcc_Nvic_Systick.h"

void Rcc_Init(void)
{
	//----------ʹÓÃÄÚ²¿RC¾§ÕñHSI 64MHz----------- 
	RCC_DeInit(); 										//½«ÍâÉèRCC¼Ä´æÆ÷ÖØÉèΪȱʡֵ 
	RCC_HSICmd(ENABLE); 								//ÄÚ²¿Ê±ÖÓʹÄÜ
	while(RCC_GetFlagStatus(RCC_FLAG_HSIRDY)== RESET);	//µÈ´ýHSI¾ÍÐ÷ 
	
	FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);	//Ñ¡ÔñFLASHԤȡָ»º´æµÄÄ£,Ԥȡָ»º´æʹÄÜ 
	FLASH_SetLatency(FLASH_Latency_2);   				//ÉèÖÃFLASH´æ´¢Æ÷ÑÓʱʱÖÓÖÜÆÚÊýFLASH_Latency_2  2ÑÓʱÖÜÆÚ   
	
	
	RCC_HCLKConfig(RCC_SYSCLK_Div1);   					//ÉèÖÃAHBʱÖÓ£¨HCLK£© RCC_SYSCLK_Div1¡ª¡ªAHBʱÖÓ = ϵͳʱÖÓ 
	RCC_PCLK2Config(RCC_HCLK_Div1);   					//ÉèÖøßËÙAHBʱÖÓ£¨PCLK2£©RCC_HCLK_Div1¡ª¡ªAPB2ʱÖÓ = HCLK     
	RCC_PCLK1Config(RCC_HCLK_Div2); 					//ÉèÖõÍËÙAHBʱÖÓ£¨PCLK1£©RCC_HCLK_Div2¡ª¡ªAPB1ʱÖÓ = HCLK/2      
	RCC_PLLConfig(RCC_PLLSource_HSI_Div2, RCC_PLLMul_16);	//ÉèÖÃPLLʱÖÓÔ´¼°±¶ÆµÏµÊý£¬ÆµÂÊΪ8/2*16=64Mhz    
	RCC_PLLCmd(ENABLE);   								//ʹÄÜPLL 
	
	while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET); //¼ì²éÖ¸¶¨µÄRCC±ê־λ(PLL×¼±¸ºÃ±êÖ¾)ÉèÖÃÓë·ñ    
	RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);  		//ÉèÖÃϵͳʱÖÓ£¨SYSCLK£© 
	while(RCC_GetSYSCLKSource() != 0x08);     			//0x08£ºPLL×÷ΪϵͳʱÖÓ   

//	//----------ʹÓÃÍⲿRC¾§Õñ 72MHz-----------  
//    RCC_DeInit();           //³õʼ»¯ÎªÈ±Ê¡Öµ  
//    RCC_HSEConfig(RCC_HSE_ON);  //ʹÄÜÍⲿµÄ¸ßËÙʱÖÓ   
//    while(RCC_GetFlagStatus(RCC_FLAG_HSERDY) == RESET); //µÈ´ýÍⲿ¸ßËÙʱÖÓʹÄܾÍÐ÷  
//      
//    FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);   //Enable Prefetch Buffer  
//    FLASH_SetLatency(FLASH_Latency_2);      //Flash 2 wait state  
//      
//    RCC_HCLKConfig(RCC_SYSCLK_Div1);        //HCLK = SYSCLK  
//    RCC_PCLK2Config(RCC_HCLK_Div1);         //PCLK2 =  HCLK  
//    RCC_PCLK1Config(RCC_HCLK_Div2);         //PCLK1 = HCLK/2  
//    RCC_PLLConfig(RCC_PLLSource_HSE_Div1,RCC_PLLMul_9); //PLLCLK = 8MHZ * 9 =72MHZ  
//    RCC_PLLCmd(ENABLE);         //Enable PLLCLK  
//  
//    while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET); //Wait till PLLCLK is ready  
//    RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);  //Select PLL as system clock  
//    while(RCC_GetSYSCLKSource()!=0x08);     //Wait till PLL is used as system clock source  
		
}

void Nvic_Init(void)
{
	NVIC_InitTypeDef NVIC_InitStructure;
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
	
	/* Enable and set EXTI Interrupt to the lowest priority */
    NVIC_InitStructure.NVIC_IRQChannel = DECAIRQ_EXTI_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 15;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

    NVIC_Init(&NVIC_InitStructure);
}

int Systick_Init(void)
{
	int time_retry = 500;
	if (SysTick_Config(64000))
	{
        /* Capture error */
        while (time_retry--);
		return 1;
    }
    NVIC_SetPriority(SysTick_IRQn, 5);

    return 0;
	
}

void delay_us(uint32_t nTimer)  
{  
    uint32_t i=0;  
    for(i=0;i<nTimer;i++){  
        __NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();
		__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();
		__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();  
        __NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();
		__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();
		__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();__NOP();  
        __NOP();__NOP();__NOP();__NOP(); 
    }  
}

void delay_ms(uint32_t nTimer)  
{  
    uint32_t i=1000*nTimer;  
    delay_us(i);  
}