rakeshk.r
Member level 2
This is my CRC32 function which yeilds ff79a6f1 for '3B' as input. But, when I check for '3B' in this website https://www.lammertbies.nl/comm/info/crc-calculation.html, it shows 0x630906A9 as CRC output. Why is this different from my output? If my function is not working correctly, then how can to fix it? Thank you.
Code Verilog - [expand] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 function [31:0] crc_32(byte unsigned data[]); bit [7:0] d; bit [31:0] newcrc, crc,c; int i; crc=0; for (i=0; i<data.size(); i++) begin d = data[i]; $display("Byte data for which crc to be calculated = %0h",d); c = crc; newcrc[0] = d[6] ^ d[0] ^ c[24] ^ c[30]; newcrc[1] = d[7] ^ d[6] ^ d[1] ^ d[0] ^ c[24] ^ c[25] ^ c[30] ^ c[31]; newcrc[2] = d[7] ^ d[6] ^ d[2] ^ d[1] ^ d[0] ^ c[24] ^ c[25] ^ c[26] ^ c[30] ^ c[31]; newcrc[3] = d[7] ^ d[3] ^ d[2] ^ d[1] ^ c[25] ^ c[26] ^ c[27] ^ c[31]; newcrc[4] = d[6] ^ d[4] ^ d[3] ^ d[2] ^ d[0] ^ c[24] ^ c[26] ^ c[27] ^ c[28] ^ c[30]; newcrc[5] = d[7] ^ d[6] ^ d[5] ^ d[4] ^ d[3] ^ d[1] ^ d[0] ^ c[24] ^ c[25] ^ c[27] ^ c[28] ^ c[29] ^ c[30] ^ c[31]; newcrc[6] = d[7] ^ d[6] ^ d[5] ^ d[4] ^ d[2] ^ d[1] ^ c[25] ^ c[26] ^ c[28] ^ c[29] ^ c[30] ^ c[31]; newcrc[7] = d[7] ^ d[5] ^ d[3] ^ d[2] ^ d[0] ^ c[24] ^ c[26] ^ c[27] ^ c[29] ^ c[31]; newcrc[8] = d[4] ^ d[3] ^ d[1] ^ d[0] ^ c[0] ^ c[24] ^ c[25] ^ c[27] ^ c[28]; newcrc[9] = d[5] ^ d[4] ^ d[2] ^ d[1] ^ c[1] ^ c[25] ^ c[26] ^ c[28] ^ c[29]; newcrc[10] = d[5] ^ d[3] ^ d[2] ^ d[0] ^ c[2] ^ c[24] ^ c[26] ^ c[27] ^ c[29]; newcrc[11] = d[4] ^ d[3] ^ d[1] ^ d[0] ^ c[3] ^ c[24] ^ c[25] ^ c[27] ^ c[28]; newcrc[12] = d[6] ^ d[5] ^ d[4] ^ d[2] ^ d[1] ^ d[0] ^ c[4] ^ c[24] ^ c[25] ^ c[26] ^ c[28] ^ c[29] ^ c[30]; newcrc[13] = d[7] ^ d[6] ^ d[5] ^ d[3] ^ d[2] ^ d[1] ^ c[5] ^ c[25] ^ c[26] ^ c[27] ^ c[29] ^ c[30] ^ c[31]; newcrc[14] = d[7] ^ d[6] ^ d[4] ^ d[3] ^ d[2] ^ c[6] ^ c[26] ^ c[27] ^ c[28] ^ c[30] ^ c[31]; newcrc[15] = d[7] ^ d[5] ^ d[4] ^ d[3] ^ c[7] ^ c[27] ^ c[28] ^ c[29] ^ c[31]; newcrc[16] = d[5] ^ d[4] ^ d[0] ^ c[8] ^ c[24] ^ c[28] ^ c[29]; newcrc[17] = d[6] ^ d[5] ^ d[1] ^ c[9] ^ c[25] ^ c[29] ^ c[30]; newcrc[18] = d[7] ^ d[6] ^ d[2] ^ c[10] ^ c[26] ^ c[30] ^ c[31]; newcrc[19] = d[7] ^ d[3] ^ c[11] ^ c[27] ^ c[31]; newcrc[20] = d[4] ^ c[12] ^ c[28]; newcrc[21] = d[5] ^ c[13] ^ c[29]; newcrc[22] = d[0] ^ c[14] ^ c[24]; newcrc[23] = d[6] ^ d[1] ^ d[0] ^ c[15] ^ c[24] ^ c[25] ^ c[30]; newcrc[24] = d[7] ^ d[2] ^ d[1] ^ c[16] ^ c[25] ^ c[26] ^ c[31]; newcrc[25] = d[3] ^ d[2] ^ c[17] ^ c[26] ^ c[27]; newcrc[26] = d[6] ^ d[4] ^ d[3] ^ d[0] ^ c[18] ^ c[24] ^ c[27] ^ c[28] ^ c[30]; newcrc[27] = d[7] ^ d[5] ^ d[4] ^ d[1] ^ c[19] ^ c[25] ^ c[28] ^ c[29] ^ c[31]; newcrc[28] = d[6] ^ d[5] ^ d[2] ^ c[20] ^ c[26] ^ c[29] ^ c[30]; newcrc[29] = d[7] ^ d[6] ^ d[3] ^ c[21] ^ c[27] ^ c[30] ^ c[31]; newcrc[30] = d[7] ^ d[4] ^ c[22] ^ c[28] ^ c[31]; newcrc[31] = d[5] ^ c[23] ^ c[29]; $display("check crc = %0h", newcrc); end $display("CRC calculation completed"); return newcrc; endfunction