#include "flash.h"
#include "stm32f10x.h"

#if FLASH_SIZE<256
#define SECTOR_SIZE 1024 //字节
#else 
#define SECTOR_SIZE	2048
#endif		 
uint16_t FLASH_BUF[SECTOR_SIZE/2];//最多是2K字节

//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.
uint16_t FLASH_ReadHalfWord(uint32_t faddr)
{
	return *(uint16_t*)faddr; 
}


//不检查的写入
//WriteAddr:起始地址
//pBuffer:数据指针
//NumToWrite:半字(16位)数   
void FLASH_Write_NoCheck(uint32_t WriteAddr,uint16_t *pBuffer,uint16_t NumToWrite)   
{ 			 		 
	uint16_t 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.)
void FLASH_Write(uint32_t WriteAddr,uint16_t *pBuffer,uint16_t NumToWrite)	
{
	uint32_t secpos;	   //扇区地址
	uint16_t secoff;	   //扇区内偏移地址(16位字计算)
	uint16_t secremain; //扇区内剩余地址(16位字计算)	   
	uint16_t i;    
	uint32_t offaddr;   //去掉0X08000000后的地址
	
	if(WriteAddr<FLASH_BASE||(WriteAddr>=(FLASH_BASE+1024*FLASH_SIZE)))
		return;		//非法地址
	FLASH_Unlock();						//解锁
	offaddr=WriteAddr-FLASH_BASE;		//实际偏移地址.
	secpos=offaddr/SECTOR_SIZE;			//扇区地址  0~512
	secoff=(offaddr%SECTOR_SIZE)/2;		//在扇区内的偏移(2个字节为基本单位.)
	secremain=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) 
	{
		FLASH_Read(secpos*SECTOR_SIZE+FLASH_BASE,FLASH_BUF,SECTOR_SIZE/2);//读出整个扇区的内容
		for(i=0;i<secremain;i++)//校验数据
		{
			if(FLASH_BUF[secoff+i]!=0XFFFF)
				break;//需要擦除
		}
		if(i<secremain)//需要擦除
		{
			FLASH_ErasePage(secpos*SECTOR_SIZE+FLASH_BASE);//擦除这个扇区
			for(i=0;i<secremain;i++)//复制
			{
				FLASH_BUF[i+secoff]=pBuffer[i];	  
			}
			FLASH_Write_NoCheck(secpos*SECTOR_SIZE+FLASH_BASE,FLASH_BUF,SECTOR_SIZE/2);//写入整个扇区  
		}
		else
		{
			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*2);	//写地址偏移	   
			NumToWrite-=secremain;	//字节(16位)数递减
			if(NumToWrite>(SECTOR_SIZE/2))
				secremain=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 FLASH_Read(uint32_t ReadAddr,uint16_t *pBuffer,uint16_t NumToRead)   	
{
	uint16_t i;
	
	for(i=0;i<NumToRead;i++)
	{
		pBuffer[i]=FLASH_ReadHalfWord(ReadAddr);//读取2个字节.
		ReadAddr+=2;//偏移2个字节.	
	}
}

void FLASH_Write_2KB(uint32_t WriteAddr, uint8_t *pBuffer) 
{
	u16 i, WriteData;	
	INTX_DISABLE();
	FLASH_Unlock();
	FLASH_ErasePage(WriteAddr);
 if(FLASH_SIZE<0x100) //1KB/P
	  FLASH_ErasePage(WriteAddr+1024);
	for(i=0; i<2048; i+=2)
	{
		WriteData = (pBuffer[i+1]<<8) + pBuffer[i];
		FLASH_ProgramHalfWord(WriteAddr, WriteData);
		WriteAddr+=2;
	}
	
	FLASH_Lock();
    INTX_ENABLE();
}