53、NandFlash的芯片id读取、数据读取、擦除与烧写
1、采用竖线的方法分析
2、cpu的nandflash的控制器帮忙做了硬件部分的时序
3、页、块和oob
4、读nandflash的时序图
5、其他时序
6、nandflash相关的代码
#include "s3c2440_soc.h"
#include "my_printf.h"
void nand_init(void)
{
#define TACLS 0
#define TWRPH0 1
#define TWRPH1 0
/*设置NAND FLASH的时序*/
NFCONF = (TACLS<<12) | (TWRPH0<<8) | (TWRPH1<<4);
/*使能NAND FLASH控制器,初始化ECC，禁止片选*/
NFCONT = (1<<4) | (1<<1) | (1<<0);
}
void nand_select(void)
{
/*使能片选*/
NFCONT &=~(1<<1);
}
void nand_deselect(void)
{
/*禁止片选*/
NFCONT |= (1<<1);
}
void nand_cmd(unsigned char cmd)
{
volatile int i;
NFCCMD = cmd;
for(i=0; i<10; i++);
}
void nand_addr_byte(unsigned char addr)
{
volatile int i;
NFADDR = addr;
for(i=0; i<10; i++);
}
unsigned char nand_data(void)
{
return NFDATA;
}
void nand_w_data(unsigned char val)
{
NFDATA = val;
}
void wait_ready(void)
{
while (!(NFSTAT & 1));
}
void nand_chip_id(void)
{
unsigned char buf[5]={0};
nand_select();
nand_cmd(0x90);
nand_addr_byte(0x00);
buf[0] = nand_data();
buf[1] = nand_data();
buf[2] = nand_data();
buf[3] = nand_data();
buf[4] = nand_data();
nand_deselect();
printf("maker id = 0x%x\n\r",buf[0]);
printf("device id = 0x%x\n\r",buf[1]);
printf("3rd byte = 0x%x\n\r",buf[2]);
printf("4th byte = 0x%x\n\r",buf[3]);
printf("page size = %d kb\n\r",1 << (buf[3] & 0x03));
printf("block size = %d kb\n\r",64 << ((buf[3] >> 4) & 0x03));
printf("5th byte = 0x%x\n\r",buf[4]);
}
void nand_read(unsigned int addr, unsigned char *buf, unsigned int len)
{
int i = 0;
int page = addr / 2048;
int col = addr & (2048 - 1);
nand_select();
while (i < len)
{
/* 发出00h命令 */
nand_cmd(00);
/* 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30h命令 */
nand_cmd(0x30);
/* 等待就绪 */
wait_ready();
/* 读数据 */
for (; (col < 2048) && (i < len); col++)
{
buf[i++] = nand_data();
}
if (i == len)
break;
col = 0;
page++;
}
nand_deselect();
}
int nand_erase(unsigned int addr, unsigned int len)
{
int page = addr / 2048;
if (addr & (0x1FFFF))
{
printf("nand_erase err, addr is not block align\n\r");
return -1;
}
if (len & (0x1FFFF))
{
printf("nand_erase err, len is not block align\n\r");
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;
}
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();
}
void do_read_nand_flash(void)
{
unsigned int addr;
volatile unsigned char *p;
int i, j;
unsigned char c;
unsigned char str[16];
unsigned char buf[64];
/* 获得地址 */
printf("Enter the address to read: ");
addr = get_uint();
nand_read(addr, buf, 64);
p = (volatile unsigned char *)buf;
printf("Data : \n\r");
/* 长度固定为64 */
for (i = 0; i < 4; i++)
{
/* 每行打印16个数据 */
for (j = 0; j < 16; j++)
{
/* 先打印数值 */
c = *p++;
str[j] = c;
printf("%02x ", c);
}
printf(" ; ");
for (j = 0; j < 16; j++)
{
/* 后打印字符 */
if (str[j] < 0x20 || str[j] > 0x7e) /* 不可视字符 */
putchar('.');
else
putchar(str[j]);
}
printf("\n\r");
}
}
void do_erase_nand_flash(void)
{
unsigned int addr;
/* 获得地址 */
printf("Enter the address of sector to erase: ");
addr = get_uint();
printf("erasing ...\n\r");
nand_erase(addr, 128*1024);
}
void do_write_nand_flash(void)
{
unsigned int addr;
unsigned char str[100];
int i, j;
unsigned int val;
/* 获得地址 */
printf("Enter the address of sector to write: ");
addr = get_uint();
printf("Enter the string to write: ");
gets(str);
printf("writing ...\n\r");
nand_write(addr, str, strlen(str)+1);
}
void nand_flash_test(void)
{
char c;
while (1)
{
/* 打印菜单, 供我们选择测试内容 */
printf("[s] Scan nand flash\n\r");
printf("[e] Erase nand flash\n\r");
printf("[w] Write nand flash\n\r");
printf("[r] Read nand flash\n\r");
printf("[q] quit\n\r");
printf("Enter selection: ");
c = getchar();
printf("%c\n\r", c);
/* 测试内容:
* 1. 识别nand flash
* 2. 擦除nand flash某个扇区
* 3. 编写某个地址
* 4. 读某个地址
*/
switch (c)
{
case 'q':
case 'Q':
return;
break;
case 's':
case 'S':
nand_chip_id();
break;
case 'e':
case 'E':
do_erase_nand_flash();
break;
case 'w':
case 'W':
do_write_nand_flash();
break;
case 'r':
case 'R':
do_read_nand_flash();
break;
default:
break;
}
}
}
6、通过nandflash重定位代码
void copy2sdram(void)
{
/* 要从lds文件中获得 __code_start, __bss_start
* 然后从0地址把数据复制到__code_start
*/
extern int __code_start, __bss_start;
volatile unsigned int *dest = (volatile unsigned int *)&__code_start;
volatile unsigned int *end = (volatile unsigned int *)&__bss_start;
volatile unsigned int *src = (volatile unsigned int *)0;
int len;
len = ((int)&__bss_start) - ((int)&__code_start);
if (isBootFromNorFlash())
{
while (dest < end)
{
*dest++ = *src++;
}
}
else
{
nand_init();
nand_read(src, dest, len);
}
}
int isBootFromNorFlash(void)
{
volatile unsigned int *p = (volatile unsigned int *)0;
unsigned int val = *p;
*p = 0x12345678;
if (*p == 0x12345678)
{
/* 写成功, 对应nand启动 */
*p = val;
return 0;
}
else
{
return 1;
}
}
7、makefile要将在片内4K执行的程序放在前面
objs = start.o init.o interrupt.o nand_flash.o led.o uart.o main.o exception.o timer.o my_printf.o string_utils.o lib1funcs.o
8、添加字符长度判断函数
/**
* strlen - Find the length of a string
* @s: The string to be sized
*/
int strlen(const char * s)
{
const char *sc;
for (sc = s; *sc != '\0'; ++sc)
/* nothing */;
return sc - s;
}