NandFlash 控制器操作实例:读Flash
发布时间:2020-12-15 19:54:11 所属栏目:百科 来源:网络整理
导读:摘要: 本文以S3C2440为例来讲解NAND FLASH控制器的使用方法. 例程中故意将一部分代码放置到 nand 的4k 字节之后,因无法自动拷贝到steppingstone,所以需要读取nand中的内容到sdram。 代码执行示意图: nand.lds SECTIONS { firtst 0x00000000 : { head .o ini
摘要: 本文以S3C2440为例来讲解NAND FLASH控制器的使用方法. 例程中故意将一部分代码放置到 nand 的4k 字节之后,因无法自动拷贝到steppingstone,所以需要读取nand中的内容到sdram。代码执行示意图:
SECTIONS {
firtst 0x00000000 : { head.o init.o nand.o}
/*head.o、init.o和nand.o组成,加载地址和运行地址都是0,运行前不需要重新移动代码*/
second 0x30000000 : AT(4096) { main.o }
/*由main.o组成,运行地址为0x30000000,加载地址为4096(即偏移地址),表明段second *存放在编译所得映象文件地址2048处,在运行前将它重定位到地址0x30000000处,*/
}
@******************************************************************************
@ File:head.s
@ 功能:设置SDRAM,将程序复制到SDRAM,然后跳到SDRAM继续执行
@******************************************************************************
.text
.global _start
_start:
@函数disable_watch_dog,memsetup,init_nand,nand_read_ll在init.c中定义
ldr sp,=4096 @设置堆栈
bl disable_watch_dog @关WATCH DOG
bl memsetup @初始化SDRAM
bl nand_init @初始化NAND Flash
@将NAND Flash中地址4096开始的1024字节代码(main.c编译得到)复制到SDRAM中
@nand_read_ll函数需要3个参数:
ldr r0,=0x30000000 @1. 目标地址=0x30000000,这是SDRAM的起始地址
mov r1,#4096 @2. 源地址 = 4096,连接的时候,main.c中的代码都存在NAND Flash地址4096开始处
mov r2,#2048 @3. 复制长度= 2048(bytes),对于本实验的main.c,这是足够了
bl nand_read @调用C函数nand_read
ldr sp,=0x34000000 @设置栈
ldr lr,=halt_loop @设置返回地址
ldr pc,=main @b指令和bl指令只能前后跳转32M的范围,所以这里使用向pc赋值的方法进行跳转
halt_loop:
b halt_loop
/* WOTCH DOG register */
#define WTCON (*(volatile unsigned long *)0x53000000)
/* SDRAM regisers */
#define MEM_CTL_BASE 0x48000000
void disable_watch_dog();
void memsetup();
/*上电后,WATCH DOG默认是开着的,要把它关掉 */
void disable_watch_dog()
{
WTCON = 0;
}
/* 设置控制SDRAM的13个寄存器 */
void memsetup()
{
int i = 0;
unsigned long *p = (unsigned long *)MEM_CTL_BASE;
/* SDRAM 13个寄存器的值 */
unsigned long const mem_cfg_val[]={ 0x22011110,//BWSCON
0x00000700,//BANKCON0
0x00000700,//BANKCON1
0x00000700,//BANKCON2
0x00000700,//BANKCON3
0x00000700,//BANKCON4
0x00000700,//BANKCON5
0x00018005,//BANKCON6
0x00018005,//BANKCON7
0x008C07A3,//REFRESH
0x000000B1,//BANKSIZE
0x00000030,//MRSRB6
0x00000030,//MRSRB7
};
for(; i < 13; i++)
p[i] = mem_cfg_val[i];
}
#define LARGER_NAND_PAGE
#define GSTATUS1 (*(volatile unsigned int *)0x560000B0)
#define BUSY 1
#define NAND_SECTOR_SIZE 512
#define NAND_BLOCK_MASK (NAND_SECTOR_SIZE - 1)
#define NAND_SECTOR_SIZE_LP 2048
#define NAND_BLOCK_MASK_LP (NAND_SECTOR_SIZE_LP - 1)
typedef unsigned int S3C24X0_REG32;
/* NAND FLASH (see S3C2410 manual chapter 6) */
typedef struct {
S3C24X0_REG32 NFCONF;
S3C24X0_REG32 NFCMD;
S3C24X0_REG32 NFADDR;
S3C24X0_REG32 NFDATA;
S3C24X0_REG32 NFSTAT;
S3C24X0_REG32 NFECC;
} S3C2410_NAND;
/* NAND FLASH (see S3C2440 manual chapter 6,www.100ask.net) */
typedef struct {
S3C24X0_REG32 NFCONF;
S3C24X0_REG32 NFCONT;
S3C24X0_REG32 NFCMD;
S3C24X0_REG32 NFADDR;
S3C24X0_REG32 NFDATA;
S3C24X0_REG32 NFMECCD0;
S3C24X0_REG32 NFMECCD1;
S3C24X0_REG32 NFSECCD;
S3C24X0_REG32 NFSTAT;
S3C24X0_REG32 NFESTAT0;
S3C24X0_REG32 NFESTAT1;
S3C24X0_REG32 NFMECC0;
S3C24X0_REG32 NFMECC1;
S3C24X0_REG32 NFSECC;
S3C24X0_REG32 NFSBLK;
S3C24X0_REG32 NFEBLK;
} S3C2440_NAND;
typedef struct {
void (*nand_reset)(void);
void (*wait_idle)(void);
void (*nand_select_chip)(void);
void (*nand_deselect_chip)(void);
void (*write_cmd)(int cmd);
void (*write_addr)(unsigned int addr);
unsigned char (*read_data)(void);
}t_nand_chip;
static S3C2410_NAND * s3c2410nand = (S3C2410_NAND *)0x4e000000;
static S3C2440_NAND * s3c2440nand = (S3C2440_NAND *)0x4e000000;
static t_nand_chip nand_chip;
/* 供外部调用的函数 */
void nand_init(void);
void nand_read(unsigned char *buf,unsigned long start_addr,int size);
/* NAND Flash操作的总入口,它们将调用S3C2410或S3C2440的相应函数 */
static void nand_reset(void);
static void wait_idle(void);
static void nand_select_chip(void);
static void nand_deselect_chip(void);
static void write_cmd(int cmd);
static void write_addr(unsigned int addr);
static unsigned char read_data(void);
/* S3C2410的NAND Flash处理函数 */
static void s3c2410_nand_reset(void);
static void s3c2410_wait_idle(void);
static void s3c2410_nand_select_chip(void);
static void s3c2410_nand_deselect_chip(void);
static void s3c2410_write_cmd(int cmd);
static void s3c2410_write_addr(unsigned int addr);
static unsigned char s3c2410_read_data();
/* S3C2440的NAND Flash处理函数 */
static void s3c2440_nand_reset(void);
static void s3c2440_wait_idle(void);
static void s3c2440_nand_select_chip(void);
static void s3c2440_nand_deselect_chip(void);
static void s3c2440_write_cmd(int cmd);
static void s3c2440_write_addr(unsigned int addr);
static unsigned char s3c2440_read_data(void);
/* S3C2410的NAND Flash操作函数 */
/* 复位 */
static void s3c2410_nand_reset(void)
{
s3c2410_nand_select_chip();// 选中芯片
s3c2410_write_cmd(0xff); // 复位命令
s3c2410_wait_idle(); // 等待nand就绪
s3c2410_nand_deselect_chip();// 取消选中
}
/* 等待NAND Flash就绪 */
static void s3c2410_wait_idle(void)
{
int i;
volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFSTAT;
while(!(*p & BUSY))
for(i=0; i<10; i++);
}
/* 发出片选信号 */
static void s3c2410_nand_select_chip(void)
{
int i;
s3c2410nand->NFCONF &= ~(1<<11);
for(i=0; i<10; i++);
}
/* 取消片选信号 */
static void s3c2410_nand_deselect_chip(void)
{
s3c2410nand->NFCONF |= (1<<11);
}
/* 发出命令 */
static void s3c2410_write_cmd(int cmd)
{
volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFCMD;
*p = cmd;
}
/* 发出地址 */
static void s3c2410_write_addr(unsigned int addr)
{
int i;
volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFADDR;
*p = addr & 0xff;
for(i=0; i<10; i++);
*p = (addr >> 9) & 0xff;
for(i=0; i<10; i++);
*p = (addr >> 17) & 0xff;
for(i=0; i<10; i++);
*p = (addr >> 25) & 0xff;
for(i=0; i<10; i++);
}
/* 读取数据 */
static unsigned char s3c2410_read_data(void)
{
volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFDATA;
return *p;
}
/* S3C2440的NAND Flash操作函数 */
/* 复位 */
static void s3c2440_nand_reset(void)
{
s3c2440_nand_select_chip();// 选中芯片
s3c2440_write_cmd(0xff); // 复位命令
s3c2440_wait_idle(); /// 等待nand就绪
s3c2440_nand_deselect_chip();// 取消选中
}
/* 等待NAND Flash就绪 */
static void s3c2440_wait_idle(void)
{
int i;
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFSTAT;//状态寄存器,只用到位0. 0 : busy 1 : ready
while(!(*p & BUSY))
for(i=0; i<10; i++);
}
/* 发出片选信号 */
static void s3c2440_nand_select_chip(void)
{
int i;
s3c2440nand->NFCONT &= ~(1<<1);
for(i=0; i<10; i++);
}
/* 取消片选信号 */
static void s3c2440_nand_deselect_chip(void)
{
s3c2440nand->NFCONT |= (1<<1);
}
/* 发出命令 */
static void s3c2440_write_cmd(int cmd)
{
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFCMD;//NFCMD 不同的flash命令不一样,发送命令信号
*p = cmd;
}
/* 发出地址(小页 4周期) */
static void s3c2440_write_addr(unsigned int addr)
{
int i;
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR;
*p = addr & 0xff;
for(i=0; i<10; i++);
*p = (addr >> 9) & 0xff;
for(i=0; i<10; i++);
*p = (addr >> 17) & 0xff;
for(i=0; i<10; i++);
*p = (addr >> 25) & 0xff;
for(i=0; i<10; i++);
}
/* 发出地址(大页 5周期) */
static void s3c2440_write_addr_lp(unsigned int addr)
{
int i;
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR;//NFADDR当向该寄存器写入数据时,芯片向nand发送地址信号
int col,page;
//#define NAND_SECTOR_SIZE_LP 2048
//#define NAND_BLOCK_MASK_LP (NAND_SECTOR_SIZE_LP - 1)
col = addr & NAND_BLOCK_MASK_LP; //2048 -1 = 22222222221b,这里是屏蔽高位,取低11位数据,因为寻址空间只到 2k = 2^11,所以最多用11位,这里直接不考虑第12位
//参考链接:http://bbs.csdn.net/topics/360034390
//或者参考http://blog.csdn.net/czg13548930186/article/details/75043343 大页寻址方式
page = addr / NAND_SECTOR_SIZE_LP;//2048 = 2^11,这里将数据右移11位,获取高位数据
*p = col & 0xff; /* Column Address A0~A7 */
for(i=0; i<10; i++);
*p = (col >> 8) & 0x0f; /* Column Address A8~A11 */
for(i=0; i<10; i++);
*p = page & 0xff; /* Row Address A12~A19 */
for(i=0; i<10; i++);
*p = (page >> 8) & 0xff; /* Row Address A20~A27 */
for(i=0; i<10; i++);
*p = (page >> 16) & 0x03; /* Row Address A28~A29 */
for(i=0; i<10; i++);
}
/* 读取数据 */
static unsigned char s3c2440_read_data(void)
{
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFDATA;//数据寄存器,读写都是这个寄存器. 只用到它的低 8 位
return *p;
}
/* 在第一次使用NAND Flash前,复位一下NAND Flash */
static void nand_reset(void)
{
nand_chip.nand_reset();
}
static void wait_idle(void)
{
nand_chip.wait_idle();
}
static void nand_select_chip(void)
{
int i;
nand_chip.nand_select_chip();
for(i=0; i<10; i++);
}
static void nand_deselect_chip(void)
{
nand_chip.nand_deselect_chip();
}
static void write_cmd(int cmd)
{
nand_chip.write_cmd(cmd);
}
static void write_addr(unsigned int addr)
{
nand_chip.write_addr(addr);
}
static unsigned char read_data(void)
{
return nand_chip.read_data();
}
/* 初始化NAND Flash */
void nand_init(void)
{
#define TACLS 0
#define TWRPH0 3
#define TWRPH1 0
/* 判断是S3C2410还是S3C2440 */
if ((GSTATUS1 == 0x32410000) || (GSTATUS1 == 0x32410002))
{
nand_chip.nand_reset = s3c2410_nand_reset;
nand_chip.wait_idle = s3c2410_wait_idle;
nand_chip.nand_select_chip = s3c2410_nand_select_chip;
nand_chip.nand_deselect_chip = s3c2410_nand_deselect_chip;
nand_chip.write_cmd = s3c2410_write_cmd;
nand_chip.write_addr = s3c2410_write_addr;
nand_chip.read_data = s3c2410_read_data;
/* 使能NAND Flash控制器,初始化ECC,禁止片选,设置时序 */
s3c2410nand->NFCONF = (1<<15)|(1<<12)|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0);
}
else
{
nand_chip.nand_reset = s3c2440_nand_reset;
nand_chip.wait_idle = s3c2440_wait_idle;
nand_chip.nand_select_chip = s3c2440_nand_select_chip;
nand_chip.nand_deselect_chip = s3c2440_nand_deselect_chip;
nand_chip.write_cmd = s3c2440_write_cmd;
#ifdef LARGER_NAND_PAGE
nand_chip.write_addr = s3c2440_write_addr_lp;
#else
nand_chip.write_addr = s3c2440_write_addr;
#endif
nand_chip.read_data = s3c2440_read_data;
/* 设置时序 */
s3c2440nand->NFCONF = (TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4);
/* 使能NAND Flash控制器,禁止片选 */
s3c2440nand->NFCONT = (1<<4)|(1<<1)|(1<<0);
}
/* 复位NAND Flash */
nand_reset();
}
/* 读函数 */
void nand_read(unsigned char *buf,int size)//在head.S中设置的r0 r1 r2 分别为该函数的三个参数
{
int i,j;
//NAND Flash 每次读操作是以page为单位的,一个page在此是2048byte(不同的NAND Flash的page大小不一定相同),
//因为2047的二进制表示是11个1, 即22222222221, 一个数如果是2048的倍数,低11bit必须是0, 即 ****00000000000
//所以把一个数跟2047按位与就可判断它是不是2048的倍数。
#ifdef LARGER_NAND_PAGE
if ((start_addr & NAND_BLOCK_MASK_LP) || (size & NAND_BLOCK_MASK_LP)) {
return ; /* 地址或长度不对齐 */
}
#else
if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
return ; /* 地址或长度不对齐 */
}
#endif
/* 选中芯片 */
nand_select_chip();
for(i=start_addr; i < (start_addr + size);) {
/* 发出READ0命令 */
write_cmd(0);
/* Write Address */
write_addr(i);
#ifdef LARGER_NAND_PAGE
write_cmd(0x30);
#endif
wait_idle();
#ifdef LARGER_NAND_PAGE
for(j=0; j < NAND_SECTOR_SIZE_LP; j++,i++) {
#else
for(j=0; j < NAND_SECTOR_SIZE; j++,i++) {
#endif
*buf = read_data();
buf++;
}
}
/* 取消片选信号 */
nand_deselect_chip();
return ;
/*总结一下:(1)选中芯片(2)发送00h(3)发出地址(4)发30h(5)等待就绪(6)读一页数据*/
}
#define GPFCON (*(volatile unsigned long *)0x56000050)
#define GPFDAT (*(volatile unsigned long *)0x56000054)
#define GPF4_out (1<<(4*2))
#define GPF5_out (1<<(5*2))
#define GPF6_out (1<<(6*2))
void wait(volatile unsigned long dly)
{
for(; dly > 0; dly--);
}
int main(void)
{
unsigned long i = 0;
GPFCON = GPF4_out|GPF5_out|GPF6_out; // 将LED1-3对应的GPF4/5/6三个引脚设为输出
while(1){
wait(30000);
GPFDAT = (~(i<<4)); // 根据i的值,点亮LED1-3
if(++i == 8)
i = 0;
}
return 0;
}
objs := head.o init.o nand.o main.o
# $^ 代表所有的依赖文件。 $@--目标文件,$<--第一个依赖文件。
nand.bin : $(objs)
arm-linux-ld -Tnand.lds -o nand_elf $^
arm-linux-objcopy -O binary -S nand_elf $@ # binary:二进制的 -S:不从源文件复制重定位信息和符号信息到目标文件中去
arm-linux-objdump -D -m arm nand_elf > nand.dis # -D:反汇编所有段 -m arm:指定反汇编文件使用arm架构
%.o:%.c
arm-linux-gcc -Wall -c -O2 -o $@ $< #-Wall:打开警告信息 -O2:2级优化(常用) -c:只编译不连接
%.o:%.S
arm-linux-gcc -Wall -c -O2 -o $@ $<
clean:
rm -f nand.dis nand.bin nand_elf *.o
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