flash.c

用闪存实现单片机存储器的扩展 学会闪存的编程方法

/******************************************************/
/*    文件名: Flash.c                                 */
/*    功能描述:                                       */
/******************************************************/

#define START_ADDR     ((unsigned char volatile xdata *) 0x0000)
#define ADDR_UNLOCK1   ((unsigned char volatile xdata *) 0x5555)
#define ADDR_UNLOCK2   ((unsigned char volatile xdata *) 0x2AAA)

sfr AUXR  = 0x8E;

unsigned char DataBuf[64];

void init_data()
{
	unsigned char i;
	for(i=0; i<64; i++)
		DataBuf[i] = i;
}

void delay()
{
	unsigned int i;
	for(i=0; i<1000; i++);
}

void unprotect()				// 取消软件数据保护
{
	*ADDR_UNLOCK1 = 0xAA;
	*ADDR_UNLOCK2 = 0x55;
	*ADDR_UNLOCK1 = 0x80;
	*ADDR_UNLOCK1 = 0xAA;
	*ADDR_UNLOCK2 = 0x55;
	*ADDR_UNLOCK1 = 0x20;
}

void erase()					// 芯片擦除
{
	*ADDR_UNLOCK1 = 0xAA;
	*ADDR_UNLOCK2 = 0x55;
	*ADDR_UNLOCK1 = 0x80;
	*ADDR_UNLOCK1 = 0xAA;
	*ADDR_UNLOCK2 = 0x55;
	*ADDR_UNLOCK1 = 0x10;
}

void unp_write(unsigned char *Buf, unsigned int len)	// 无保护写
{
	unsigned int i;
	unsigned char *Des, *Src;
	Des = Buf;
	Src = DataBuf;
	for(i=0; i<len; i++)
	{
		*Des = *Src;
		Des++;
		Src++;
	}
}

void p_write(unsigned char *Buf, unsigned int len)		// 带保护写
{
	unsigned int i;
	unsigned char *Des, *Src;
	Des = Buf;
	Src = DataBuf + 63;
	*ADDR_UNLOCK1 = 0xAA;
	*ADDR_UNLOCK2 = 0x55;
	*ADDR_UNLOCK1 = 0xA0;
	for(i=0; i<len; i++)
	{
		*Des = *Src;
		Des++;
		Src--;
	}
}

void main()
{
	AUXR = 0x2;
	init_data();

	p_write(START_ADDR, 64);		// 带保护写
	delay();

	unp_write(START_ADDR, 64);		// 不带保护写
	delay();

	unprotect();					// 去除保护
	unp_write(START_ADDR, 64);		
	delay();

	erase();						// 擦除	

	while(1);
}