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   首页>技术专栏>Nandflash专栏>Samsung公司256字节数据产生3字节ECC校验码、及用ECC码检查数据错误的软件代码

Samsung公司256字节数据产生3字节ECC校验码、及用ECC码检查数据错误的软件代码

    
高速程序代码下载速度200KBytes/S以上内置对于GDB Remote Serial Protocol协议支持FoxICE仿真器完美支持GDB 的 File IO扩展协议免费赠送Eclipse for ARM V 3.2.1集成开发环境支持Nand Flash( S3C2410/2440/2442可任选一种 )的烧写,支持超低电压的处理器调试, 目标范围为:0.65 ~ 5.5V
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/*****************************************************************************/
/* */
/* PROJECT : SAMSUNG ECC for 256byte */
/* FILE : SAMSUNG_ECC.c */
/* PURPOSE : This file implements core ECC algorithms adopted */
/* Hamming Error Correction and Detection Algorithm */
/* */
/*---------------------------------------------------------------------------*/
/* */
/* COPYRIGHT 2000-2004, SAMSUNG ELECTRONICS CO., LTD. */
/* ALL RIGHTS RESERVED */
/* */
/* Permission is hereby granted to licensees of Samsung Electronics */
/* Co., Ltd. products to use or abstract this computer program for the */
/* sole purpose of implementing a product based on Samsung */
/* Electronics Co., Ltd. products. No other rights to reproduce, use, */
/* or disseminate this computer program, whether in part or in whole, */
/* are granted. */
/* */
/* Samsung Electronics Co., Ltd. makes no representation or warranties */
/* with respect to the performance of this computer program, and */
/* specifically disclaims any responsibility for any damages, */
/* special or consequential, connected with the use of this program. */
/* */
/*---------------------------------------------------------------------------*/
/* */
/* REVISION HISTORY */
/* */
/* 13-NOV-2003 [Chang JongBaek] : first writing */
/* 03-MAR-2004 [ Kim YoungGon ] : Second writing */
/* 03-MAR-2004 [ Lee JaeBum ] : Third writing */
/*---------------------------------------------------------------------------*/
/* */
/* NOTES */
/* */
/* - Make ECC parity code of 256bytes is represented */
/* And ECC compare & Correction code is also represented */
/* */
/*****************************************************************************/
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/timeb.h>
#include <string.h>

/*****************************************************************************/
/* Address Types */
/*****************************************************************************/

typedef unsigned char * address_t; /* address (pointer) */
typedef unsigned long address_value_t; /* address (for calculation) */

typedef unsigned long ULONG; /* address (for calculation) */

typedef unsigned int uint;
typedef unsigned char uchar;


/*****************************************************************************/
/* Integer Types */
/*****************************************************************************/

typedef unsigned int uint32_t; /* unsigned 4 byte integer */
typedef signed int int32_t; /* signed 4 byte integer */
typedef unsigned short uint16_t; /* unsigned 2 byte integer */
typedef signed short int16_t; /* signed 2 byte integer */
typedef unsigned char uint8_t; /* unsigned 1 byte integer */
typedef signed char int8_t; /* signed 1 byte integer */
typedef unsigned int UINT32; /* unsigned 4 byte integer */
typedef unsigned char UINT8; /* unsigned 1 byte integer */
typedef signed int INT32; /* signed 4 byte integer */

typedef unsigned int UINT; /* unsigned 4 byte integer */
typedef signed int INT; /* signed 4 byte integer */
typedef unsigned short USHORT; /* unsigned 2 byte integer */
typedef signed short SHORT; /* signed 2 byte integer */
typedef unsigned char UCHAR; /* unsigned 1 byte integer */
typedef signed char CHAR; /* signed 1 byte integer */

UCHAR ecc_gen[3];

typedef enum {
ECC_NO_ERROR = 0, /* no error */
ECC_CORRECTABLE_ERROR = 1, /* one bit data error */
ECC_ECC_ERROR = 2, /* one bit ECC error */
ECC_UNCORRECTABLE_ERROR = 3 /* uncorrectable error */
} eccdiff_t;

void make_ecc_256(unsigned char*, unsigned char*);
eccdiff_t compare_ecc(unsigned char*, unsigned char*, unsigned char*, int, unsigned char);

/*****************************************************************************/
/* */
/* NAME */
/* make_ecc_256 */
/* DESCRIPTION */
/* This function generates 3 byte ECC for 512 byte data. */
/* (Software ECC) */
/* PARAMETERS */
/* ecc_buf the location where ECC should be stored */
/* data_buf given data */
/* RETURN VALUES */
/* none */
/* */
/*****************************************************************************/
void make_ecc_256(unsigned char* ecc_buf, unsigned char* data_buf)
{

unsigned int i;
unsigned int tmp;
unsigned int uiparity = 0;
unsigned int parityCol, ecc = 0;
unsigned int parityCol4321 = 0, parityCol4343 = 0, parityCol4242 = 0, parityColTot = 0;
unsigned int* Data = (unsigned int*)(data_buf);
unsigned int Xorbit=0;

for( i = 0; i < 8; i++)
{
parityCol = *Data++;
tmp = *Data++; parityCol ^= tmp; parityCol4242 ^= tmp;
tmp = *Data++; parityCol ^= tmp; parityCol4343 ^= tmp;
tmp = *Data++; parityCol ^= tmp; parityCol4343 ^= tmp; parityCol4242 ^= tmp;
tmp = *Data++; parityCol ^= tmp; parityCol4321 ^= tmp;
tmp = *Data++; parityCol ^= tmp; parityCol4242 ^= tmp; parityCol4321 ^= tmp;
tmp = *Data++; parityCol ^= tmp; parityCol4343 ^= tmp; parityCol4321 ^= tmp;
tmp = *Data++; parityCol ^= tmp; parityCol4242 ^= tmp; parityCol4343 ^= tmp; parityCol4321 ^= tmp;

parityColTot ^= parityCol;

tmp = (parityCol >> 16) ^ parityCol;
tmp = (tmp >> 8) ^ tmp;
tmp = (tmp >> 4) ^ tmp;
tmp = ((tmp >> 2) ^ tmp) & 0x03;
if ((tmp == 0x01) || (tmp == 0x02))
{
uiparity ^= i;
Xorbit ^= 0x01;
}
}

tmp = (parityCol4321 >> 16) ^ parityCol4321;
tmp = (tmp << 8) ^ tmp;
tmp = (tmp >> 4) ^ tmp;
tmp = (tmp >> 2) ^ tmp;
ecc |= ((tmp << 1) ^ tmp) & 0x200; // p128

tmp = (parityCol4343 >> 16) ^ parityCol4343;
tmp = (tmp >> 8) ^ tmp;
tmp = (tmp << 4) ^ tmp;
tmp = (tmp << 2) ^ tmp;
ecc |= ((tmp << 1) ^ tmp) & 0x80; // p64

tmp = (parityCol4242 >> 16) ^ parityCol4242;
tmp = (tmp >> 8) ^ tmp;
tmp = (tmp << 4) ^ tmp;
tmp = (tmp >> 2) ^ tmp;
ecc |= ((tmp << 1) ^ tmp) & 0x20; // p32

tmp = parityColTot & 0xFFFF0000;
tmp = tmp >> 16;
tmp = (tmp >> 8) ^ tmp;
tmp = (tmp >> 4) ^ tmp;
tmp = (tmp << 2) ^ tmp;
ecc |= ((tmp << 1) ^ tmp) & 0x08; // p16

tmp = parityColTot & 0xFF00FF00;
tmp = (tmp >> 16) ^ tmp;
tmp = (tmp >> 8);
tmp = (tmp >> 4) ^ tmp;
tmp = (tmp >> 2) ^ tmp;
ecc |= ((tmp << 1) ^ tmp) & 0x02; // p8

tmp = parityColTot & 0xF0F0F0F0 ;
tmp = (tmp << 16) ^ tmp;
tmp = (tmp >> 8) ^ tmp;
tmp = (tmp << 2) ^ tmp;
ecc |= ((tmp << 1) ^ tmp) & 0x800000; // p4

tmp = parityColTot & 0xCCCCCCCC ;
tmp = (tmp << 16) ^ tmp;
tmp = (tmp >> 8) ^ tmp;
tmp = (tmp << 4) ^ tmp;
tmp = (tmp >> 2);
ecc |= ((tmp << 1) ^ tmp) & 0x200000; // p2

tmp = parityColTot & 0xAAAAAAAA ;
tmp = (tmp << 16) ^ tmp;
tmp = (tmp >> 8) ^ tmp;
tmp = (tmp >> 4) ^ tmp;
tmp = (tmp << 2) ^ tmp;
ecc |= (tmp & 0x80000); // p1

ecc |= (uiparity & 0x01) <<11; // parit256_1
ecc |= (uiparity & 0x02) <<12; // parit512_1
ecc |= (uiparity & 0x04) <<13; // parit1024_1

if (Xorbit)
{
ecc |= (ecc ^ 0x00A8AAAA)>>1;
}
else
{
ecc |= (ecc >> 1);
}

ecc = ~ecc;
*(ecc_buf + 2) = (unsigned char) (ecc >> 16);
*(ecc_buf + 1) = (unsigned char) (ecc >> 8);
*(ecc_buf + 0) = (unsigned char) (ecc);
}


/*****************************************************************************/
/* */
/* NAME */
/* compare_ecc_256 */
/* DESCRIPTION */
/* This function compares two ECCs and indicates if there is an error. */
/* PARAMETERS */
/* ecc_data1 one ECC to be compared */
/* ecc_data2 the other ECC to be compared */
/* page_data content of data page */
/* offset where the error occurred */
/* corrected correct data */
/* RETURN VALUES */
/* Upon successful completion, compare_ecc returns SSR_SUCCESS. */
/* Otherwise, corresponding error code is returned. */
/* */
/*****************************************************************************/
eccdiff_t compare_ecc_256(uint8_t *iEccdata1, uint8_t *iEccdata2,
uint8_t *pPagedata, int32_t pOffset, uint8_t pCorrected)
{

uint32_t iCompecc = 0, iEccsum = 0;
uint32_t iFindbyte = 0;
uint32_t iIndex;
uint32_t nT1 = 0, nT2 =0;
uint8_t iNewvalue;
uint8_t iFindbit = 0;

uint8_t *pEcc1 = (uint8_t *)iEccdata1;
uint8_t *pEcc2 = (uint8_t *)iEccdata2;

for ( iIndex = 0; iIndex <2; iIndex++)
{
nT1 ^= (((*pEcc1) >> iIndex) & 0x01);
nT2 ^= (((*pEcc2) >> iIndex) & 0x01);
}

for (iIndex = 0; iIndex < 3; iIndex++)
iCompecc |= ((~(*pEcc1++) ^ ~(*pEcc2++)) << iIndex * 8);

for(iIndex = 0; iIndex < 24; iIndex++) {
iEccsum += ((iCompecc >> iIndex) & 0x01);
}

switch (iEccsum) {
case 0 :
printf("RESULT : no error\n");
return ECC_NO_ERROR;

case 1 :
printf("RESULT : ECC 1 bit error\n");
return ECC_ECC_ERROR;

case 11 :
if (nT1 != nT2)
{
iFindbyte = ( ((iCompecc >> 15 & 1) << 7) + ((iCompecc >> 13 & 1) << 6)
+ ((iCompecc >> 11 & 1) << 5) + ((iCompecc >> 9 & 1) << 4) + ((iCompecc >> 7 & 1) << 3)
+ ((iCompecc >> 5 & 1) << 2) + ((iCompecc >> 3 & 1) << 1) + (iCompecc >> 1 & 1) );
iFindbit = (uint8_t)(((iCompecc >> 23 & 1) << 2) + ((iCompecc >> 21 & 1) << 1) + (iCompecc >> 19 & 1));
iNewvalue = (uint8_t)(pPagedata[iFindbyte] ^ (1 << iFindbit));
printf("iCompecc = %d\n",iCompecc);
printf("RESULT : one bit error\r\n");
printf("byte = %d, bit = %d\r\n", iFindbyte, iFindbit);
printf("corrupted = %x, corrected = %x\r\n", pPagedata[iFindbyte], iNewvalue);
if (pOffset != NULL) {
pOffset = iFindbyte;
}
if (pCorrected != NULL) {
pCorrected = iNewvalue;
}

return ECC_CORRECTABLE_ERROR;
}
else
return ECC_UNCORRECTABLE_ERROR;

default :
printf("RESULT : unrecoverable error\n");
return ECC_UNCORRECTABLE_ERROR;
}
}

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