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https://opencores.org/ocsvn/mmcfpgaconfig/mmcfpgaconfig/trunk
Subversion Repositories mmcfpgaconfig
[/] [mmcfpgaconfig/] [trunk/] [sw/] [mmc_crc7.cpp] - Rev 6
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// // MMC Card CRC7 calculator and checker // www.openchip.org // // #include <iostream> #include <stdio.h> using namespace std; char crc7[8]; char cmd[49]; void do_crc7(char c) { char c3; char c0; // last stage and input bit c0 = (crc7[6] == c) ? '0' : '1'; // c3 = (crc7[2] == c0) ? '0' : '1'; // shift register crc7[6] = crc7[5]; crc7[5] = crc7[4]; crc7[4] = crc7[3]; crc7[3] = c3; crc7[2] = crc7[1]; crc7[1] = crc7[0]; crc7[0] = c0; } /* CMD17 Argument=0x00000100 CRC7=0x43 OK, checked! CMD17 Argument=0x00004000 CRC7=0x8F OK, checked! */ void calc_crc(int command, unsigned int arg) { int i; unsigned int mask; // fill CMD mask = 1; for (i=0;i<6;i++) { if (mask & command) { cmd[7-i] = '1'; } else { cmd[7-i]='0'; } mask <<= 1; } // fill ARG mask = 1; for (i=0;i<32;i++) { if (mask & arg) { cmd[39-i] = '1'; } else { cmd[39-i]='0'; } mask <<= 1; } // clear CRC for (i=0;i<7;i++) crc7[i] = '0'; // calc CRC for (i=0;i<40;i++) do_crc7(cmd[i]); // copy CRC cmd[40] = crc7[6]; cmd[41] = crc7[5]; cmd[42] = crc7[4]; cmd[43] = crc7[3]; cmd[44] = crc7[2]; cmd[45] = crc7[1]; cmd[46] = crc7[0]; } int main (int argc, char *argv[]) { char quit; int i; // clear CRC crc7[7] = 0; for (i=0;i<7;i++) crc7[i] = '0'; // clear CMD, ARG cmd[48] = 0; for (i=0;i<48;i++) cmd[i] = '0'; cmd[1] = '1'; // Start bit cmd[47] = '1'; // Stop Bit // check CRC calculation calc_crc(0,0); printf("\n\rTest CMD0 ,0x0 %s", cmd); calc_crc(17,0x100); printf("\n\rTest CMD17,0x0100 %s", cmd); calc_crc(17,0x4000); printf("\n\rTest CMD17,0x04000 %s", cmd); printf("\n\rCalc CRCs"); calc_crc(0,0); printf("\n\rTest CMD0 ,0x0 %s", cmd); calc_crc(1,0x80FF8000); printf("\n\rTest CMD1 ,0x80FF8000 %s", cmd); calc_crc(2,0); printf("\n\rTest CMD2 ,0x0 %s", cmd); calc_crc(3,0x10000); printf("\n\rTest CMD3 ,0x10000 %s", cmd); calc_crc(7,0x10000); printf("\n\rTest CMD7 ,0x10000 %s", cmd); calc_crc(11,0x0000); printf("\n\rTest CMD11,0x00000 %s", cmd); calc_crc(55,0x0000); printf("\n\rTest CMD55,0x00000 %s", cmd); calc_crc(41,0x80FF8000); printf("\n\rTest ACMD41,0x80FF8000 %s", cmd); cin >>quit; return 0; }