S3C2440裸机------Nor Flash编程_擦写读

1.读NorFlash

我们首先来实现读flash的函数，我们默认每次读取64个字节，然后我们把读取到的内容打印出来，其中前面打印数值，后面打印字符，对于不可见字符用...代替。

void do_read_nor_flash(void)

{

unsigned int addr;

volatile unsigned char *p;

int i, j;

unsigned char c;

unsigned char str[16];

/* 获得地址 */

printf("Enter the address to read: ");

addr = get_uint();

p = (volatile unsigned char *)addr;

printf("Data : nr");

/* 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("nr");

}

}

2.擦除Nroflash

从芯片手册看到，要想擦除，我们首先解锁，然后发出80命令，然后再次解锁，然后再向某一个地址发出30命令即可。

代码如下：

void do_erase_nor_flash(void)

{

unsigned int addr;

/* 获得地址 */

printf("Enter the address of sector to erase: ");

addr = get_uint();

printf("erasing ...nr");

nor_cmd(0x555, 0xaa);    /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(0x555, 0x80); /* erase sector */

nor_cmd(0x555, 0xaa);    /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(addr>>1, 0x30); /* 发出扇区地址 */

wait_ready(addr);

}

我们通过读数据bit6，如果它不变化了，说明擦除或者写结束了。所以wait_ready()函数这样写。 

void wait_ready(unsigned int addr)

{

unsigned int val;

unsigned int pre;

pre = nor_dat(addr>>1);

val = nor_dat(addr>>1);

while ((val & (1<<6)) != (pre & (1<<6)))

{

pre = val;

val = nor_dat(addr>>1);

}

}

3.写NorFlash

要想写NorFlash，我们首先解锁，然后在地址555H写入A0H命令，然后在某个地址写入某个之即可，这里的数据时16位的。

代码如下：

void do_write_nor_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 ...nr");

/* str[0],str[1]==>16bit 

* str[2],str[3]==>16bit 

*/

i = 0;

j = 1;

while (str[i] && str[j])

{

val = str[i] + (str[j]<<8);

/* 烧写 */

nor_cmd(0x555, 0xaa); /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(0x555, 0xa0); /* program */

nor_cmd(addr>>1, val);

/* 等待烧写完成 : 读数据, Q6无变化时表示结束 */

wait_ready(addr);

i += 2;

j += 2;

addr += 2;

}

val = str[i];

/* 烧写 */

nor_cmd(0x555, 0xaa); /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(0x555, 0xa0); /* program */

nor_cmd(addr>>1, val);

/* 等待烧写完成 : 读数据, Q6无变化时表示结束 */

wait_ready(addr);

}

4.完整代码

#include "my_printf.h"

#include "string_utils.h"

#define NOR_FLASH_BASE  0  /* jz2440, nor-->cs0, base addr = 0 */

/* 比如:   55H 98 

 * 本意是: 往(0 + (0x55)<<1)写入0x98

 */

void nor_write_word(unsigned int base, unsigned int offset, unsigned int val)

{

volatile unsigned short *p = (volatile unsigned short *)(base + (offset << 1));

*p = val;

}

/* offset是基于NOR的角度看到 */

void nor_cmd(unsigned int offset, unsigned int cmd)

{

nor_write_word(NOR_FLASH_BASE, offset, cmd);

}

unsigned int nor_read_word(unsigned int base, unsigned int offset)

{

volatile unsigned short *p = (volatile unsigned short *)(base + (offset << 1));

return *p;

}

unsigned int nor_dat(unsigned int offset)

{

return nor_read_word(NOR_FLASH_BASE, offset);

}

void wait_ready(unsigned int addr)

{

unsigned int val;

unsigned int pre;

pre = nor_dat(addr>>1);

val = nor_dat(addr>>1);

while ((val & (1<<6)) != (pre & (1<<6)))

{

pre = val;

val = nor_dat(addr>>1);

}

}

/* 进入NOR FLASH的CFI模式

 * 读取各类信息

 */

void do_scan_nor_flash(void)

{

char str[4];

unsigned int size;

int regions, i;

int region_info_base;

int block_addr, blocks, block_size, j;

int cnt;

int vendor, device;

/* 打印厂家ID、设备ID */

nor_cmd(0x555, 0xaa);    /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(0x555, 0x90);    /* read id */

vendor = nor_dat(0);

device = nor_dat(1);

nor_cmd(0, 0xf0);        /* reset */

nor_cmd(0x55, 0x98);  /* 进入cfi模式 */

str[0] = nor_dat(0x10);

str[1] = nor_dat(0x11);

str[2] = nor_dat(0x12);

str[3] = '';

printf("str = %snr", str);

/* 打印容量 */

size = 1<<(nor_dat(0x27));

printf("vendor id = 0x%x, device id = 0x%x, nor size = 0x%x, %dMnr", vendor, device, size, size/(1024*1024));

/* 打印各个扇区的起始地址 */

/* 名词解释:

*    erase block region : 里面含有1个或多个block, 它们的大小一样

* 一个nor flash含有1个或多个region

* 一个region含有1个或多个block(扇区)

* Erase block region information:

*    前2字节+1    : 表示该region有多少个block 

*    后2字节*256  : 表示block的大小

*/

regions = nor_dat(0x2c);

region_info_base = 0x2d;

block_addr = 0;

printf("Block/Sector start Address:nr");

cnt = 0;

for (i = 0; i < regions; i++)

{

blocks = 1 + nor_dat(region_info_base) + (nor_dat(region_info_base+1)<<8);

block_size = 256 * (nor_dat(region_info_base+2) + (nor_dat(region_info_base+3)<<8));

region_info_base += 4;

// printf("nrregion %d, blocks = %d, block_size = 0x%x, block_addr = 0x%xnr", i, blocks, block_size, block_addr);

for (j = 0; j < blocks; j++)

{

/* 打印每个block的起始地址 */

//printf("0x%08x ", block_addr);

printHex(block_addr);

putchar(' ');

cnt++;

block_addr += block_size;

if (cnt % 5 == 0)

printf("nr");

}

}

printf("nr");

/* 退出CFI模式 */

nor_cmd(0, 0xf0);

}

void do_erase_nor_flash(void)

{

unsigned int addr;

/* 获得地址 */

printf("Enter the address of sector to erase: ");

addr = get_uint();

printf("erasing ...nr");

nor_cmd(0x555, 0xaa);    /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(0x555, 0x80); /* erase sector */

nor_cmd(0x555, 0xaa);    /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(addr>>1, 0x30); /* 发出扇区地址 */

wait_ready(addr);

}

void do_write_nor_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 ...nr");

/* str[0],str[1]==>16bit 

* str[2],str[3]==>16bit 

*/

i = 0;

j = 1;

while (str[i] && str[j])

{

val = str[i] + (str[j]<<8);

/* 烧写 */

nor_cmd(0x555, 0xaa); /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(0x555, 0xa0); /* program */

nor_cmd(addr>>1, val);

/* 等待烧写完成 : 读数据, Q6无变化时表示结束 */

wait_ready(addr);

i += 2;

j += 2;

addr += 2;

}

val = str[i];

/* 烧写 */

nor_cmd(0x555, 0xaa); /* 解锁 */

nor_cmd(0x2aa, 0x55); 

nor_cmd(0x555, 0xa0); /* program */

nor_cmd(addr>>1, val);

/* 等待烧写完成 : 读数据, Q6无变化时表示结束 */

wait_ready(addr);

}

void do_read_nor_flash(void)

{

unsigned int addr;

volatile unsigned char *p;

int i, j;

unsigned char c;

unsigned char str[16];

/* 获得地址 */

printf("Enter the address to read: ");

addr = get_uint();

p = (volatile unsigned char *)addr;

printf("Data : nr");

/* 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("nr");

}

}

void nor_flash_test(void)

{

char c;

while (1)

{

/* 打印菜单, 供我们选择测试内容 */

printf("[s] Scan nor flashnr");

printf("[e] Erase nor flashnr");

printf("[w] Write nor flashnr");

printf("[r] Read nor flashnr");

printf("[q] quitnr");

printf("Enter selection: ");

c = getchar();

printf("%cnr", c);

/* 测试内容:

* 1. 识别nor flash

* 2. 擦除nor 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':

do_scan_nor_flash();

break;

case 'e':

case 'E':

do_erase_nor_flash();

break;

case 'w':

case 'W':

do_write_nor_flash();

break;

case 'r':

case 'R':

do_read_nor_flash();

break;

default:

break;

}

}

}