#include "stm32_flash.h"


//读取指定地址的半字(16位数据)
//faddr:读地址(此地址必须为2的倍数!!)
//返回值:对应数据.
vu16 STM32_FLASH_ReadHalfWord(u32 faddr)
{
	return *(vu16*)faddr; 
} 

//不检查的写入
//WriteAddr:起始地址
//pBuffer:数据指针
//NumToWrite:半字(16位)数   
void STM32_FLASH_Write_NoCheck(u32 WriteAddr,u16 *pBuffer,u16 NumToWrite)   
{ 			 		 
	u16 i;
	for(i=0;i<NumToWrite;i++)
	{
		FLASH_ProgramHalfWord(WriteAddr,pBuffer[i]);
	    WriteAddr+=2;//地址增加2.
	}  
}

//从指定地址开始写入指定长度的数据
//WriteAddr:起始地址(此地址必须为2的倍数)
//pBuffer:数据指针
//NumToWrite:半字(16位)数(就是要写入的16位数据的个数.)
#if STM32_FLASH_SIZE<256
	#define STM32_SECTOR_SIZE 1024 //字节
#else 
	#define STM32_SECTOR_SIZE	2048
#endif		 
u16 STM32_FLASH_BUF[STM32_SECTOR_SIZE/2];//最多是2K字节
void STM32_FLASH_Write(u32 WriteAddr,u16 *pBuffer,u16 NumToWrite)	
{
	u32 secpos;	   //扇区地址
	u16 secoff;	   //扇区内偏移地址(16位字计算)
	u16 secremain; //扇区内剩余地址(16位字计算)	   
 	u16 i;    
	u32 offaddr;   //去掉0X08000000后的地址
	if(WriteAddr<STM32_FLASH_BASE||(WriteAddr>=(STM32_FLASH_BASE+1024*STM32_FLASH_SIZE)))return;//非法地址
	FLASH_Unlock();						//解锁
	offaddr=WriteAddr-STM32_FLASH_BASE;		//实际偏移地址.
	secpos=offaddr/STM32_SECTOR_SIZE;			//扇区地址 
	secoff=(offaddr%STM32_SECTOR_SIZE)/2;		//在扇区内的偏移(2个字节为基本单位.)
	secremain=STM32_SECTOR_SIZE/2-secoff;		//扇区剩余空间大小   
	if(NumToWrite<=secremain)secremain=NumToWrite;//不大于该扇区范围
	while(1) 
	{	
		STM32_FLASH_Read(secpos*STM32_SECTOR_SIZE+STM32_FLASH_BASE,STM32_FLASH_BUF,STM32_SECTOR_SIZE/2);//读出整个扇区的内容
		for(i=0;i<secremain;i++)//校验数据
		{
			if(STM32_FLASH_BUF[secoff+i]!=0XFFFF)
				break;//需要擦除  	  
		}
		if(i<secremain)//需要擦除
		{
			FLASH_ErasePage(secpos*STM32_SECTOR_SIZE+STM32_FLASH_BASE);//擦除这个扇区
			for(i=0;i<secremain;i++)//复制
			{
				STM32_FLASH_BUF[i+secoff]=pBuffer[i];	  
			}
			STM32_FLASH_Write_NoCheck(secpos*STM32_SECTOR_SIZE+STM32_FLASH_BASE,STM32_FLASH_BUF,STM32_SECTOR_SIZE/2);//写入整个扇区  
		}
		else 
			STM32_FLASH_Write_NoCheck(WriteAddr,pBuffer,secremain);//写已经擦除了的,直接写入扇区剩余区间. 				   
		if(NumToWrite==secremain)
			break;//写入结束了
		else//写入未结束
		{
			secpos++;				//扇区地址增1
			secoff=0;				//偏移位置为0 	 
		   	pBuffer+=secremain;  	//指针偏移
			WriteAddr+=secremain;	//写地址偏移	   
		   	NumToWrite-=secremain;	//字节(16位)数递减
			if(NumToWrite>(STM32_SECTOR_SIZE/2))
				secremain=STM32_SECTOR_SIZE/2;//下一个扇区还是写不完
			else 
				secremain=NumToWrite;//下一个扇区可以写完了
		}	 
	}	
	FLASH_Lock();//上锁
}

//从指定地址开始读出指定长度的数据
//ReadAddr:起始地址
//pBuffer:数据指针
//NumToWrite:半字(16位)数
void STM32_FLASH_Read(u32 ReadAddr,u16 *pBuffer,u16 NumToRead)   	
{
	u16 i;
	for(i=0;i<NumToRead;i++)
	{
		pBuffer[i]=STM32_FLASH_ReadHalfWord(ReadAddr);//读取2个字节.
		ReadAddr+=2;//偏移2个字节.	
	}
}