S3C2440裸机------NandFlash编程_擦除与烧写

1.擦除

NandFlash是以块为单位进行擦除的，一个块是128K，从上面的时序图我们可以看到，首先我们要发出60命令，然后发出三个行地址，然后发送D0H，然后等待擦除结束。

int nand_erase(unsigned int addr, unsigned int len)

{

int page = addr / 2048;

if (addr & (0x1FFFF))

{

printf("nand_erase err, addr is not block alignnr");

return -1;

}

if (len & (0x1FFFF))

{

printf("nand_erase err, len is not block alignnr");

return -1;

}

nand_select(); 

while (1)

{

page = addr / 2048;

nand_cmd(0x60);

/* row/page addr */

nand_addr_byte(page & 0xff);

nand_addr_byte((page>>8) & 0xff);

nand_addr_byte((page>>16) & 0xff);

nand_cmd(0xD0);

wait_ready();

len -= (128*1024);

if (len == 0)

break;

addr += (128*1024);

}

nand_deselect();

return 0;

}

2.烧写

从上面的时序图可以看到，要想烧写NandFlash，我们首先发出80命令，然后发出五个地址，然后开始写数据，数据写完之后发出10命令，然后开始等待烧写完成。

void nand_write(unsigned int addr, unsigned char *buf, unsigned int len)

{

int page = addr / 2048;

int col  = addr & (2048 - 1);

int i = 0;

nand_select(); 

while (1)

{

nand_cmd(0x80);

/* 发出地址 */

/* col addr */

nand_addr_byte(col & 0xff);

nand_addr_byte((col>>8) & 0xff);

/* row/page addr */

nand_addr_byte(page & 0xff);

nand_addr_byte((page>>8) & 0xff);

nand_addr_byte((page>>16) & 0xff);

/* 发出数据 */

for (; (col < 2048) && (i < len); )

{

nand_w_data(buf[i++]);

}

nand_cmd(0x10);

wait_ready();

if (i == len)

break;

else

{

/* 开始下一个循环page */

col = 0;

page++;

}

}

nand_deselect();

}