nand flash读写 （二） （转）

1)      根据2410寄存器定义如下的命令宏

#define NF_CMD(cmd) {rNFCMD=cmd;}

#define NF_ADDR(addr)   {rNFADDR=addr;}

#define NF_nFCE_L() {rNFCONF&=~(1<<11);}

#define NF_nFCE_H() {rNFCONF|=(1<<11);}

#define NF_RSTECC() {rNFCONF|=(1<<12);}

#define
NF_RDDATA()     (rNFDATA)

#define NF_WRDATA(data)
{rNFDATA=data;}

#define NF_WAITRB()    {while(!(rNFSTAT&(1<<0)));}

        //wait
tWB and check F_RNB pin.

 

2)      NAND 设备的初始化

static void NF_Init(void)                          //Flash 初始化

{

rNFCONF=(1<<15)|(1<<14)|(1<<13)|(1<<12)|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0);                                           //设置NAND设备的相关寄存器

    //
1  1    1     1,   1      xxx,  r
xxx,   r
xxx       

    //
En 512B 4step ECCR nFCE="H" tACLS   tWRPH0   tWRPH1

   

    NF_Reset();

}

static void NF_Reset(void)                           //Flash重置

{

    int
i;

 

    NF_nFCE_L();

    NF_CMD(0xFF);                      //reset
command

    for(i=0;i<10;i++);                  //tWB
= 100ns

    NF_WAITRB();                        //wait
200~500us;

    NF_nFCE_H();

}

 

3)      NAND设备的识别                    //#define
ID_K9F1208U0M  0xec76

static U16 NF_CheckId(void)                            //Id 辨别

{

    int
i;

    U16
id;

   

    NF_nFCE_L();

    NF_CMD(0x90);

    NF_ADDR(0x0);

   

    for(i=0;i<10;i++);                  //wait
tWB(100ns)

   

    id=NF_RDDATA()<<8;                  //
Maker code(K9F1208U:0xec)

    id|=NF_RDDATA();                    //
Devide code(K9F1208U:0x76)

   

    NF_nFCE_H();

    return
id;

}

4)      NAND 的擦操作

static int NF_EraseBlock(U32
block)

{

    U32
blockPage=(block<<5);

    int
i;

    NF_nFCE_L();

   

    NF_CMD(0x60[q1] );                            //
Erase one block 1st command

 

    NF_ADDR(blockPage&0xff);                 //
Page number="0"

    NF_ADDR((blockPage>>8)&0xff);  

    NF_ADDR((blockPage>>16)&0xff);

 

    NF_CMD(0xd0[q2] );                           //
Erase one blcok 2nd command

   

   for(i=0;i<10;i++);                       //wait
tWB(100ns)//??????

 

    NF_WAITRB();                            //
Wait tBERS max 3ms.

    NF_CMD(0x70);                           // Read
status command

 

    if
(NF_RDDATA()&0x1)                    //
Erase error

    {  

        NF_nFCE_H();

    Uart_Printf("[ERASE_ERROR:block#=%d]\n",block);

        return
0;

    }

    else

    {

        NF_nFCE_H();

        return
1;

    }

}

 

5)      NAND 的读操作

static int NF_ReadPage(U32 block,U32
page,U8 *buffer)        //读Flash

{

    int
i;

    unsigned
int blockPage;

    U8
ecc0,ecc1,ecc2;

    U8
*bufPt=buffer;

    U8
se[16];    

   

    page=page&0x1f;                                 //32页

    blockPage=(block<<5)+page;                      //1Bolck包含32页

    NF_RSTECC();                                    //
Initialize ECC

   

    NF_nFCE_L();   

    NF_CMD(0x00);                                   //
Read command

    NF_ADDR(0);                                     //
Column = 0

    NF_ADDR(blockPage&0xff);                        //

    NF_ADDR((blockPage>>8)&0xff);                   //
Block & Page num.

    NF_ADDR((blockPage>>16)&0xff);                  //

 

    for(i=0;i<10;i++);                              //wait
tWB(100ns)

   

    NF_WAITRB();                                    //
Wait tR(max 12us)

    for(i=0;i<512;i++)

    {

        *bufPt++=NF_RDDATA();                       //
Read one page

}

 

    ecc0=rNFECC0;                              //利用2410自带的硬件ECC校验

    ecc1=rNFECC1;

    ecc2=rNFECC2;

[q3]     for(i=0;i<16;i++)

    {

        se[i]=NF_RDDATA();                          //
Read spare array

                                                    //读页内冗余的16B

    }

       NF_nFCE_H();   

 

    if(ecc0==se[0]
&& ecc1==se[1] && ecc2==se[2])   //未知使用哪一种软件规范？

    {                                               //比较数据结果是否正确

    Uart_Printf("[ECC
OK:%x,%x,%x]\n",se[0],se[1],se[2]);

        return
1;

    }

    else

    {

    Uart_Printf("[ECC
ERROR(RD):read:%x,%x,%x, reg:%x,%x,%x]\n",

        se[0],se[1],se[2],ecc0,ecc1,ecc2);

        return
0;

    }      

}

 

转自：http://blog.chinaunix.net/uid-17066213-id-2834649.html

 

作者：jinweidavid