ecc.rar_ECC C_ECC c++_ecc_visual c

256ByteECC071123.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include "stdio.h" //071126 unsigned char dat[]={ 0x0 ,0x0 ,0x0 ,0x0 ,0x0 ,0x0 ,0xf ,0x5a ,0x5a ,0xf ,0xc ,0x59 ,0x3 ,0x56 ,0x55 ,0x0 , 0x65 ,0x30 ,0x33 ,0x66 ,0x3c ,0x69 ,0x6a ,0x3f ,0x3f ,0x6a ,0x69 ,0x3c ,0x66 ,0x33 ,0x30 ,0x65 , 0x66 ,0x33 ,0x30 ,0x65 ,0x3f ,0x6a ,0x69 ,0x3c ,0x3c ,0x69 ,0x6a ,0x3f ,0x65 ,0x30 ,0x33 ,0x66 , 0x3 ,0x56 ,0x55 ,0x0 ,0x5a ,0xf ,0xc ,0x59 ,0x59 ,0xc ,0xf ,0x5a ,0x0 ,0x55 ,0x56 ,0x3 , 0x69 ,0x3c ,0x3f ,0x6a ,0x30 ,0x65 ,0x66 ,0x33 ,0x33 ,0x66 ,0x65 ,0x30 ,0x6a ,0x3f ,0x3c ,0x69 , 0xc ,0x59 ,0x5a ,0xf ,0x55 ,0x0 ,0x3 ,0x56 ,0x56 ,0x3 ,0x0 ,0x55 ,0xf ,0x5a ,0x59 ,0xc , 0xf ,0x5a ,0x59 ,0xc ,0x56 ,0x3 ,0x0 ,0x55 ,0x55 ,0x0 ,0x3 ,0x56 ,0xc ,0x59 ,0x5a ,0xf , 0x6a ,0x3f ,0x3c ,0x69 ,0x33 ,0x66 ,0x65 ,0x30 ,0x30 ,0x65 ,0x66 ,0x33 ,0x69 ,0x3c ,0x3f ,0x6a , 0x6a ,0x3f ,0x3c ,0x69 ,0x33 ,0x66 ,0x65 ,0x30 ,0x30 ,0x65 ,0x66 ,0x33 ,0x69 ,0x3c ,0x3f ,0x6a , 0xf ,0x5a ,0x59 ,0xc ,0x56 ,0x3 ,0x0 ,0x55 ,0x55 ,0x0 ,0x3 ,0x56 ,0xc ,0x59 ,0x5a ,0xf , 0xc ,0x59 ,0x5a ,0xf ,0x55 ,0x0 ,0x3 ,0x56 ,0x56 ,0x3 ,0x0 ,0x55 ,0xf ,0x5a ,0x59 ,0xc , 0x69 ,0x3c ,0x3f ,0x6a ,0x30 ,0x65 ,0x66 ,0x33 ,0x33 ,0x66 ,0x65 ,0x30 ,0x6a ,0x3f ,0x3c ,0x69 , 0x3 ,0x56 ,0x55 ,0x0 ,0x5a ,0xf ,0xc ,0x59 ,0x59 ,0xc ,0xf ,0x5a ,0x0 ,0x55 ,0x56 ,0x3 , 0x66 ,0x33 ,0x30 ,0x65 ,0x3f ,0x6a ,0x69 ,0x3c ,0x3c ,0x69 ,0x6a ,0x3f ,0x65 ,0x30 ,0x33 ,0x66 , 0x65 ,0x30 ,0x33 ,0x66 ,0x3c ,0x69 ,0x6a ,0x3f ,0x3f ,0x6a ,0x69 ,0x3c ,0x66 ,0x33 ,0x30 ,0x65 , 0x0 ,0x55 ,0x56 ,0x3 ,0x59 ,0xc ,0xf ,0x5a ,0x5a ,0xf ,0xc ,0x59 ,0x3 ,0x56 ,0x55 ,0x0 }; //071123 unsigned char ECCTable[]={ 0x0 ,0x55 ,0x56 ,0x3 ,0x59 ,0xc ,0xf ,0x5a ,0x5a ,0xf ,0xc ,0x59 ,0x3 ,0x56 ,0x55 ,0x0 , 0x65 ,0x30 ,0x33 ,0x66 ,0x3c ,0x69 ,0x6a ,0x3f ,0x3f ,0x6a ,0x69 ,0x3c ,0x66 ,0x33 ,0x30 ,0x65 , 0x66 ,0x33 ,0x30 ,0x65 ,0x3f ,0x6a ,0x69 ,0x3c ,0x3c ,0x69 ,0x6a ,0x3f ,0x65 ,0x30 ,0x33 ,0x66 , 0x3 ,0x56 ,0x55 ,0x0 ,0x5a ,0xf ,0xc ,0x59 ,0x59 ,0xc ,0xf ,0x5a ,0x0 ,0x55 ,0x56 ,0x3 , 0x69 ,0x3c ,0x3f ,0x6a ,0x30 ,0x65 ,0x66 ,0x33 ,0x33 ,0x66 ,0x65 ,0x30 ,0x6a ,0x3f ,0x3c ,0x69 , 0xc ,0x59 ,0x5a ,0xf ,0x55 ,0x0 ,0x3 ,0x56 ,0x56 ,0x3 ,0x0 ,0x55 ,0xf ,0x5a ,0x59 ,0xc , 0xf ,0x5a ,0x59 ,0xc ,0x56 ,0x3 ,0x0 ,0x55 ,0x55 ,0x0 ,0x3 ,0x56 ,0xc ,0x59 ,0x5a ,0xf , 0x6a ,0x3f ,0x3c ,0x69 ,0x33 ,0x66 ,0x65 ,0x30 ,0x30 ,0x65 ,0x66 ,0x33 ,0x69 ,0x3c ,0x3f ,0x6a , 0x6a ,0x3f ,0x3c ,0x69 ,0x33 ,0x66 ,0x65 ,0x30 ,0x30 ,0x65 ,0x66 ,0x33 ,0x69 ,0x3c ,0x3f ,0x6a , 0xf ,0x5a ,0x59 ,0xc ,0x56 ,0x3 ,0x0 ,0x55 ,0x55 ,0x0 ,0x3 ,0x56 ,0xc ,0x59 ,0x5a ,0xf , 0xc ,0x59 ,0x5a ,0xf ,0x55 ,0x0 ,0x3 ,0x56 ,0x56 ,0x3 ,0x0 ,0x55 ,0xf ,0x5a ,0x59 ,0xc , 0x69 ,0x3c ,0x3f ,0x6a ,0x30 ,0x65 ,0x66 ,0x33 ,0x33 ,0x66 ,0x65 ,0x30 ,0x6a ,0x3f ,0x3c ,0x69 , 0x3 ,0x56 ,0x55 ,0x0 ,0x5a ,0xf ,0xc ,0x59 ,0x59 ,0xc ,0xf ,0x5a ,0x0 ,0x55 ,0x56 ,0x3 , 0x66 ,0x33 ,0x30 ,0x65 ,0x3f ,0x6a ,0x69 ,0x3c ,0x3c ,0x69 ,0x6a ,0x3f ,0x65 ,0x30 ,0x33 ,0x66 , 0x65 ,0x30 ,0x33 ,0x66 ,0x3c ,0x69 ,0x6a ,0x3f ,0x3f ,0x6a ,0x69 ,0x3c ,0x66 ,0x33 ,0x30 ,0x65 , 0x0 ,0x55 ,0x56 ,0x3 ,0x59 ,0xc ,0xf ,0x5a ,0x5a ,0xf ,0xc ,0x59 ,0x3 ,0x56 ,0x55 ,0x0 }; //计算ECC代码 void NandTranResult(unsigned char reg2,unsigned char reg3,unsigned char *ECCCode) { unsigned char temp1,temp2,i,a,b; temp1=temp2=0; a=b=0x80; for(i=0;i<4;i++) { if(reg3&a) temp1|=b; b>>=1; if(reg2&a) temp1|=b; b>>=1; a>>=1; } b=0x80; for(i=0;i<4;i++) { if(reg3&a) temp2|=b; b>>=1; if(reg2&a) temp2|=b; b>>=1; a>>=1; } //将最终的ECC存入数组ECCCode ECCCode[0]=temp1;//存放高8bit ECCCode[1]=temp2;//存放中间的8bit } void NandCalECC(const unsigned char *dat,unsigned char *ECCCode) { unsigned char reg1,reg2,reg3,temp; int j; reg1=reg2=reg3=0; for(j=0;j<256;j++) { temp=ECCTable[dat[j]]; reg1^=(temp&0x3f); if(temp&0x40) { reg3^=(unsigned char)j; reg2^=(~((unsigned char)j)); } } NandTranResult(reg2,reg3,ECCCode); //计算最终的ECC码 //此处为什么要做一个求非的操作呢？？？？？？ ECCCode[0]=~ECCCode[0]; ECCCode[1]=~ECCCode[1]; ECCCode[2]=(((~reg1)<<2)|0x03); } /* * 参数解释 * dat[]:实际读取的数据 * ReadECC[]:保存数据时根据原始数据产生的ECC码 * CalECC[]:读取数据的同时产生的ECC码 */ int NandCorrectData(unsigned char *dat,unsigned char *ReadECC,unsigned char *CalECC) { unsigned char a,b,c,bit,add,i,d1,d2,d3; //计算 d1=ReadECC[0]^CalECC[0]; d2=ReadECC[1]^CalECC[1]; d3=ReadECC[2]^CalECC[2]; //printf("d1=0x%0x,d2=0x%0x,d3=0x%0x\n",d1,d2,d3); if((d1|d2|d3) == 0) { //无错误发生 printf("无错误发生\n"); return 0; } else { a=((d1>>1)^d1)&0x55; b=((d2>>1)^d2)&0x55; c=((d3>>1)^d3)&0x54; //此处的理论依据是：如果发生了1bit的ECC错误，那么ECC异或地结果是--每个配对的bit数据相反，即为0&1或者1&0 if((a == 0x55)&(b == 0x55)&(c == 0x54)) { //可校正的1bit ECC错误 //首先计算错误的Byte a=b=c=0x80; add=0; for(i=0;i<4;i++) { if(d1&a) add|=b; a>>=2; b>>=1; } for(i=0;i<4;i++) { if(d2&c) add|=b; c>>=2; b>>=1; } //计算发生错误的Bit bit=0; a=0x80; b=0x04; // printf("d3 = 0x%0x\n",d3); for(i=0;i<3;i++) { if(d3&a) { bit|=b; // printf("Detected!\n"); } else { //printf("d3=0x%0x,a=0x%0x,d3&a=0x%0x\n",d3,a,d3&a); // printf("Not Detected!\n"); } a>>=2; b>>=1; } //进行数据纠正 // printf("开始进行数据纠正\n"); // printf("Error byte: %2d,Error bit: %2d\n",add,bit); b=0x01; b<<=bit; a=dat[add]; a^=b; dat[add]=a; return 1; } else { i=0; // printf("计算异或结果d1,d2,d3中1的个数\n"); //计算异或结果d1,d2,d3中1的个数 while(d1) { if(d1&0x01) i++; d1>>=1; } while(d2) { if(d2&0x01) i++; d3>>=1; } while(d3) { if(d3&0x01) i++; d3>>=1; } if(i == 1) { //发生了ECC错误，即存放ECC数据的区域发生了错误，正常的情况下，无论多少 //bit发生了反转，都不会出现i=1的情况，出现了这种情况的原因只可能是ECC代码本身有问题 // printf("存放ECC数据的区域发生了错误\n"); return 2; } else { //不可校正的ECC错误，即Uncorrectable Error // printf("Uncorrectable Error\n"); return -1; } } } return -1; } int main(int argc, char* argv[]) { int temp,i,j,k,l,m=0; unsigned char ReadECC[3]={0,0,0},CalECC[3]={0,0,0}; NandCalECC(dat,CalECC); for(i=0;i<256;i++) { j=0x80; l=dat[i]; for(k=0;k<8;k++) { m++; dat[i]^=j; j>>=1; NandCalECC(dat,ReadECC); temp=NandCorrectData(dat,ReadECC,CalECC); if(temp == 1) { if(dat[i]==l) printf("Success\n"); else printf("Failed\n"); // printf("可以校正的错误\n"); // printf("dat[0]=0x%0x\n",dat[0]); } else if(temp == -1) { //printf("不可以校正的错误"); } else if(temp == 0) { //printf("无错误"); } else { // printf("数据区发生了错误"); } ////////////////// /* dat[5]=0x02; NandCalECC(dat,ReadECC); temp=NandCorrectData(dat,ReadECC,CalECC); if(temp == 1) { printf("可以校正的错误\n"); printf("dat[0]=0x%0x\n",dat[0]); } else if(temp == -1) { printf("不可以校正的错误"); } else if(temp == 0) { printf("无错误"); } else { printf("数据区发生了错误"); } */ ////////////////////////// } } printf("rotate times:%5d\n",m); return 0; } /********************************************** * 如有疑问，欢迎联系guopeixin@126.com ***********************************************/