s3c2440硬件篇之五：读NandFlash（2）-EDA365

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s3c2440硬件篇之五：读NandFlash（2）

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接上一篇：s3c2440硬件篇之三：NandFlash（1）介绍

s3c2440读NAND Flash的步骤：

①设置NFCONF
        在HCLK=100Mhz的情况下，TACLS=0，TWRPH0=3，TWRPH1=0，则
        NFCONF = 0x300
        使能NAND Flash控制器、禁止控制引脚信号nFCE，初始化ECC
        NFCONT = (1<<4) | (1<<1) | (1<<0)
②操作NAND Flash前，复位
        NFCONT &= ~(1<<1)        发出片选信号
        NFCMD = 0xff        reset命令
        然后循环查询NFSTAT位0，直到等于1，处于就绪态
        最后禁止片选信号，在实际使用时再使能
        NFCONT |= 0x2        禁止NAND Flash
③发出读命令
        NFCONT &= ~(1<<1)        发出片选信号
        NFCMD = 0        读命令
④发出地址信号
⑤循环查询NFSTAT，直到等于1
⑥连续读NFDATA寄存器，得到一页数据
⑦最后禁止NAND Flash片选信号
        NFCONT |= (1<<1)

Nand硬件连接：

代码详解：（参考韦东山大哥代码）

说明：本实例的目的是把一部分代码存放在NAND Flash地址4096(即4K)之后，当程序启动后通过NAND Flash控制器读出代码，执行。

（1）连接脚本nand.lds

SECTIONS {
firtst 0x00000000 : { head.o init.o nand.o}
second 0x30000000 : AT(4096) { main.o }
}

(2)head.S

@******************************************************************************
@ 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

(3)init.c

/* 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         p[i] = mem_cfg_val[i];
}

(4)nand.c ，定义一个宏#define LARGER_NAND_PAGE来区分大页小页。

#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();
    s3c2410_write_cmd(0xff); // 复位命令

    s3c2410_wait_idle();
    s3c2410_nand_deselect_chip();
}

/* 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();
    s3c2440_write_cmd(0xff); // 复位命令

    s3c2440_wait_idle();
    s3c2440_nand_deselect_chip();
}

/* 等待NAND Flash就绪 */
static void s3c2440_wait_idle(void)
{
    int i;
    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFSTAT;
    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;
    *p = cmd;
}

/* 发出地址 */
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++);
}

static void s3c2440_write_addr_lp(unsigned int addr)
{
    int i;
    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR;
    int col, page;

    col = addr & NAND_BLOCK_MASK_LP;
    page = addr / NAND_SECTOR_SIZE_LP;

    *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;
    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, 初始化ECC, 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, unsigned long start_addr, int size)
{
    int i, j;

#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       /* 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 #else
     for(j=0; j #endif
          *buf = read_data();
          buf++;
      }
    }

    /* 取消片选信号 */
    nand_deselect_chip();

    return ;
}

(5)main.c

#define GPFCON (*(volatile unsigned long *)0x56000050)
#define GPFDAT (*(volatile unsigned long *)0x56000054)
#define GPFUP (*(volatile unsigned long *)0x56000058)

#define GPF0_out (1<#define GPF1_out (1<#define GPF2_out (1<#define GPF3_out (1<
void wait(unsigned long dly)
{
    for(; dly > 0; dly--);
}

int main(void)
{
    int i=0;
    GPFCON = GPF1_out|GPF2_out|GPF3_out|GPF0_out; // 将LED1-4对应的GPB5/6/7/8四个引脚设为输出

    GPFUP = 0;

    while(1){
             GPFDAT = 0x5; // LED1,LED3将被点亮
            }
    return 0;
}

（6）Makefile:

objs := head.o init.o nand.o main.o

nand.bin : $(objs)
    arm-linux-ld -Tnand.lds    -o nand_elf $^
    arm-linux-objcopy -O binary -S nand_elf $@
    arm-linux-objdump -D -m arm nand_elf > nand.dis

%.o:%.c
    arm-linux-gcc -Wall -c -O2 -o $@ $<

%.o:%.S
    arm-linux-gcc -Wall -c -O2 -o $@ $<

clean:
    rm -f nand.dis nand.bin nand_elf *.o

说明：本程序修改自百问网韦东山大哥的程序，支持大页Nand和小页Nand。

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