标签：oid ret sdn 地址 void sel 分享图片 page art
参考资料：https://blog.csdn.net/qqliyunpeng/article/details/51180276
程序框架
/*定义寄存器*/
#define NFCONF (*((volatile unsigned long *)0x4E000000))
#define NFCONT (*((volatile unsigned long *)0x4E000004))
#define NFCMMD (*((volatile unsigned char *)0x4E000008))
#define NFADDR (*((volatile unsigned char *)0x4E00000C))
#define NFDATA (*((volatile unsigned char *)0x4E000010))
#define NFSTAT (*((volatile unsigned char *)0x4E000020))
/*nand读数据*/
void nand_read(unsigned int addr, unsigned char *buf, unsigned int len);
/*nand初始化*/
void nand_init(void)
{
/*设置时序*/
}
void nand_read(unsigned int addr, unsigned char *buf, unsigned int len)
{
}
1、NAND FLASH 控制器
Rnb:状态引脚
nFCE:
CLE:
ALE:
nFWE
nFRE:
LDATA0~LDAT7A:
芯片手册关于引脚的定义
2、根据数据手册定义寄存器
/*定义寄存器*/ #define NFCONF (*((volatile unsigned long *)0x4E000000)) #define NFCONT (*((volatile unsigned long *)0x4E000004)) #define NFCMMD (*((volatile unsigned char *)0x4E000008)) #define NFADDR (*((volatile unsigned char *)0x4E00000C)) #define NFDATA (*((volatile unsigned char *)0x4E000010)) #define NFSTAT (*((volatile unsigned char *)0x4E000020))
3、nand_init()设置正确的时序
2440端：
nand芯片端:
NFCONF寄存器：
HCLK:100HZ 10ns
根据上面的时序图设置这三个参数：
TACLS:0
TWRPH0:1
TWRPH1:0
NFCONT寄存器:
MODE:1
Reg_nCE:1
initECC:1
代码
void nand_init(void)
{
#define TACLS 0
#define TWRPH0 1
#define TWRPH1 0
/*设置时序*/
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);
}
4、void nand_read(unsigned int addr, unsigned char *buf, unsigned int len); 函数
读数据流程：
读数据流程：
根据上面的框图可以确定读数据的框架：
void nand_read(unsigned int addr, unsigned char *buf, unsigned int len)
{
int col = addr % 2048;//确定是这一页的哪一个数据
int i =0;
/* 1. 选中 */
nand_select();
while(i < len)
{
/* 2. 发出读命令00h */
nand_cmd(0x00);
/* 3. 发出地址(分5步发出) */
nand_addr(addr);
/* 4. 发出地址(分5步发出) */
nand_addr(0x30);
/* 5. 判断状态 */
nand_wait_ready();
for(;(col < 2048 && i < len); col++)
{
buf[i] = nand_data();//读数据的地址自动加1
i++;
addr++;
}
col = 0;
}
}
nand_cmd();函数
void nand_cmd(unsigned char cmd)
{
unsigned char i;
NFCMMD = cmd;
for(i = 0;i < 10; i++);
}
nand_addr();函数
void nand_addr(unsigned int addr)
{
unsigned int col = addr % 2048;
unsigned int page = addr / 2048;
volatile int i;
NFADDR = col & 0xff;
for(i = 0;i < 10; i++);
NFADDR = (col >> 8) & 0xff;
for(i = 0;i < 10; i++);
NFADDR = page & 0xff;
for(i = 0;i < 10; i++);
NFADDR = (page >> 8) & 0xff;
for(i = 0;i < 10; i++);
NFADDR = (page >> 16) & 0xff;
for(i = 0;i < 10; i++);
}
nand_data();函数
void nand_data(void)
{
return NFDATA;
}
isBootFromNorFlash();函数
int isBootFromNorFlash(void) { volatile int *p = (volatile int *)0; int val; val = *p; *p = 0x12345678; if (*p == 0x12345678) { /* 写成功, 是nand启动 */ *p = val; return 0; } else { /* NOR不能像内存一样写 */ return 1; } }
自己写bootloader——mini2440(四、初始化NAND FLASH)
标签：oid ret sdn 地址 void sel 分享图片 page art
原文地址：https://www.cnblogs.com/liuyuchun/p/9131552.html
