#include "Sys.h"
#include "conf.h"

static const uint DataBuffer[] =
{
       0x00001021, 0x20423063, 0x408450a5, 0x60c670e7, 0x9129a14a, 0xb16bc18c,
       0xd1ade1ce, 0xf1ef1231, 0x32732252, 0x52b54294, 0x72f762d6, 0x93398318,
       0xa35ad3bd, 0xc39cf3ff, 0xe3de2462, 0x34430420, 0x64e674c7, 0x44a45485,
       0xa56ab54b, 0x85289509, 0xf5cfc5ac, 0xd58d3653, 0x26721611, 0x063076d7,
       0x569546b4, 0xb75ba77a, 0x97198738, 0xf7dfe7fe, 0xc7bc48c4, 0x58e56886,
       0x78a70840, 0x18612802, 0xc9ccd9ed, 0xe98ef9af, 0x89489969, 0xa90ab92b,
       0x4ad47ab7, 0x6a961a71, 0x0a503a33, 0x2a12dbfd, 0xfbbfeb9e, 0x9b798b58,
       0xbb3bab1a, 0x6ca67c87, 0x5cc52c22, 0x3c030c60, 0x1c41edae, 0xfd8fcdec,
       0xad2abd0b, 0x8d689d49, 0x7e976eb6, 0x5ed54ef4, 0x2e321e51, 0x0e70ff9f,
       0xefbedfdd, 0xcffcbf1b, 0x9f598f78, 0x918881a9, 0xb1caa1eb, 0xd10cc12d,
       0xe16f1080, 0x00a130c2, 0x20e35004, 0x40257046, 0x83b99398, 0xa3fbb3da,
       0xc33dd31c, 0xe37ff35e, 0x129022f3, 0x32d24235, 0x52146277, 0x7256b5ea,
       0x95a88589, 0xf56ee54f, 0xd52cc50d, 0x34e224c3, 0x04817466, 0x64475424,
       0x4405a7db, 0xb7fa8799, 0xe75ff77e, 0xc71dd73c, 0x26d336f2, 0x069116b0,
       0x76764615, 0x5634d94c, 0xc96df90e, 0xe92f99c8, 0xb98aa9ab, 0x58444865,
       0x78066827, 0x18c008e1, 0x28a3cb7d, 0xdb5ceb3f, 0xfb1e8bf9, 0x9bd8abbb,
       0x4a755a54, 0x6a377a16, 0x0af11ad0, 0x2ab33a92, 0xed0fdd6c, 0xcd4dbdaa,
       0xad8b9de8, 0x8dc97c26, 0x5c644c45, 0x3ca22c83, 0x1ce00cc1, 0xef1fff3e,
       0xdf7caf9b, 0xbfba8fd9, 0x9ff86e17, 0x7e364e55, 0x2e933eb2, 0x0ed11ef0
};

bool inited = false;

void Init()
{
      #ifdef STM32F4
       RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_CRC, ENABLE);
      #else
       RCC->AHBENR |= RCC_AHBPeriph_CRC;
      #endif

       inited = true;
}

// 硬件实现的Crc
uint HardCrc(const void* buf, int len, uint crc)
{
       if (!inited) Init();

       CRC_ResetDR();
       // STM32的初值是0xFFFFFFFF，而软Crc初值是0
       CRC->DR = __REV(crc ^ 0xFFFFFFFF);
       //CRC->DR = 0xFFFFFFFF;
       uint* ptr = (uint*)buf;
       len >>= 2;
       while(len-- > 0)
       {
             CRC->DR =__REV(*ptr++); // 字节顺序倒过来,注意不是位序,不是用__RBIT指令
       }
       return CRC->DR;
       /*byte* ptr = (byte*)buf;
       while(len-- > 0)
       {
             CRC->DR = (uint)*ptr++;
       }
       return CRC->DR;*/

       /*CRC_CalcBlockCRC(ptr, len);
       return CRC_GetCRC();*/

       //UINT32 rs = CRC->DR;
       //return c_CRCTable[ ((crc >> 24) ^ rs) & 0xFF ] ^ (crc << 8);
}

void TestCrc()
{
 debug_printf("\r\n\r\n");
 debug_printf("TestCrc Start......\r\n");
 debug_printf("\r\n");

 uint size = ArrayLength(DataBuffer);

 // Sys.Crc是软校验，HardCrc是硬件实现，要求硬件实现的结果跟软件实现一致
 uint data = 0x12345678;
 uint crc = Sys.Crc((byte*)&data, 4, 0);
 uint crc2 = HardCrc(&data, 4, 0);
 Sys.ShowHex((byte*)&data, 4);
 debug_printf("\r\n\tSoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);
 // 无初值时，两者一样

 uint temp = crc;
 // 试试二次计算Crc
 crc = Sys.Crc((byte*)&crc, 4, 0);
 crc2 = HardCrc(&crc2, 4, 0);
 Sys.ShowHex((byte*)&temp, 4);
 debug_printf("\r\n\t");
 debug_printf("SoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);
 // 结果相同，但都不是0

 // 连续测试。构建8字节，前面是data，后面是前面的crc
 ulong data2 = temp;
 data2 <<= 32;
 data2 += data;
 crc = Sys.Crc((byte*)&data2, 8, 0);
 crc2 = HardCrc(&data2, 8, 0);
 Sys.ShowHex((byte*)&data2, 8);
 debug_printf("\r\n\t");
 debug_printf("SoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);
 // 结果相同，但都不是0

 // 实际应用中，先计算数据的校验，然后接着附加校验码部分，跟直接连续计算效果应该一致
 // 实际上就是数字为初值，对它自身进行校验码计算
 crc = Sys.Crc((byte*)&temp, 4, data);
 crc2 = HardCrc(&temp, 4, data);
 Sys.ShowHex((byte*)&temp, 4);
 debug_printf(" <= 0x%08x\r\n\t", data);
 debug_printf("SoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);
 // 结果不同，HardCrc结果跟8字节测试相同

 crc = Sys.Crc((byte*)&temp, 4, temp);
 crc2 = HardCrc(&temp, 4, temp);
 Sys.ShowHex((byte*)&temp, 4);
 debug_printf(" <= 0x%08x\r\n\t", temp);
 debug_printf("SoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);
 // 结果不同，SoftCrc结果跟8字节测试相同

 // 对大数据块进行校验
 debug_printf("\r\n");

 crc = Sys.Crc((byte*)DataBuffer, size*4, 0);
 crc2 = HardCrc(DataBuffer, size*4, 0);
 Sys.ShowHex((byte*)DataBuffer, 0x20);
 debug_printf("\r\n\t");
 debug_printf("SoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);
 // 无初值时，两者一样

 temp = crc;

 // 实际应用中，先计算数据的校验，然后接着附加校验码部分
 crc = Sys.Crc((byte*)&temp, 4, temp);
 crc2 = HardCrc((byte*)&temp, 4, temp);
 Sys.ShowHex((byte*)&temp, 4);
 debug_printf(" <= 0x%08x\r\n\t", temp);
 debug_printf("SoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);
 // 有初值时，两者不一样

 // 增量计算CRC
 crc = Sys.Crc((byte*)DataBuffer, size*4, 0);
 temp = crc;
 crc = Sys.Crc((byte*)&crc, 4, crc);
 crc2 = HardCrc(DataBuffer, size*4, 0);
 crc2 = HardCrc((byte*)&crc2, 4, crc2);
 Sys.ShowHex((byte*)DataBuffer, 0x20);
 debug_printf(" <= 0x%08x\r\n\t", temp);
 debug_printf("SoftCrc:0x%08x HardCrc:0x%08x \r\n", crc, crc2);

 // 测试Crc16，数据和crc部分一起计算crc16，结果为0
 debug_printf("\r\n");
 byte data16[] = { 0x01, 0x08, 0x00, 0x00};
 ushort crc16 = Sys.Crc16(data16, 4);
 debug_printf("Sys.Crc16(#%08x) = 0x%04x\r\n", __REV(*(uint*)data16), crc16);
 ushort crc17 = Sys.Crc16((byte*)&crc16, 2, crc16);
 debug_printf("Sys.Crc16(#%08x, 0x%04x) = 0x%04x\r\n", __REV(*(uint*)data16), crc16, crc17);

 debug_printf("\r\n");
 debug_printf("TestCrc Finish!\r\n");
}

//
// CRC 32 table for use under ZModem protocol, IEEE 802
// G(x) = x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1
//
static const uint c_CRCTable[ 256 ] =
{
       0x00000000, 0x04C11DB7, 0x09823B6E, 0x0D4326D9, 0x130476DC, 0x17C56B6B, 0x1A864DB2, 0x1E475005,
       0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6, 0x2B4BCB61, 0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD,
       0x4C11DB70, 0x48D0C6C7, 0x4593E01E, 0x4152FDA9, 0x5F15ADAC, 0x5BD4B01B, 0x569796C2, 0x52568B75,
       0x6A1936C8, 0x6ED82B7F, 0x639B0DA6, 0x675A1011, 0x791D4014, 0x7DDC5DA3, 0x709F7B7A, 0x745E66CD,
       0x9823B6E0, 0x9CE2AB57, 0x91A18D8E, 0x95609039, 0x8B27C03C, 0x8FE6DD8B, 0x82A5FB52, 0x8664E6E5,
       0xBE2B5B58, 0xBAEA46EF, 0xB7A96036, 0xB3687D81, 0xAD2F2D84, 0xA9EE3033, 0xA4AD16EA, 0xA06C0B5D,
       0xD4326D90, 0xD0F37027, 0xDDB056FE, 0xD9714B49, 0xC7361B4C, 0xC3F706FB, 0xCEB42022, 0xCA753D95,
       0xF23A8028, 0xF6FB9D9F, 0xFBB8BB46, 0xFF79A6F1, 0xE13EF6F4, 0xE5FFEB43, 0xE8BCCD9A, 0xEC7DD02D,
       0x34867077, 0x30476DC0, 0x3D044B19, 0x39C556AE, 0x278206AB, 0x23431B1C, 0x2E003DC5, 0x2AC12072,
       0x128E9DCF, 0x164F8078, 0x1B0CA6A1, 0x1FCDBB16, 0x018AEB13, 0x054BF6A4, 0x0808D07D, 0x0CC9CDCA,
       0x7897AB07, 0x7C56B6B0, 0x71159069, 0x75D48DDE, 0x6B93DDDB, 0x6F52C06C, 0x6211E6B5, 0x66D0FB02,
       0x5E9F46BF, 0x5A5E5B08, 0x571D7DD1, 0x53DC6066, 0x4D9B3063, 0x495A2DD4, 0x44190B0D, 0x40D816BA,
       0xACA5C697, 0xA864DB20, 0xA527FDF9, 0xA1E6E04E, 0xBFA1B04B, 0xBB60ADFC, 0xB6238B25, 0xB2E29692,
       0x8AAD2B2F, 0x8E6C3698, 0x832F1041, 0x87EE0DF6, 0x99A95DF3, 0x9D684044, 0x902B669D, 0x94EA7B2A,
       0xE0B41DE7, 0xE4750050, 0xE9362689, 0xEDF73B3E, 0xF3B06B3B, 0xF771768C, 0xFA325055, 0xFEF34DE2,
       0xC6BCF05F, 0xC27DEDE8, 0xCF3ECB31, 0xCBFFD686, 0xD5B88683, 0xD1799B34, 0xDC3ABDED, 0xD8FBA05A,
       0x690CE0EE, 0x6DCDFD59, 0x608EDB80, 0x644FC637, 0x7A089632, 0x7EC98B85, 0x738AAD5C, 0x774BB0EB,
       0x4F040D56, 0x4BC510E1, 0x46863638, 0x42472B8F, 0x5C007B8A, 0x58C1663D, 0x558240E4, 0x51435D53,
       0x251D3B9E, 0x21DC2629, 0x2C9F00F0, 0x285E1D47, 0x36194D42, 0x32D850F5, 0x3F9B762C, 0x3B5A6B9B,
       0x0315D626, 0x07D4CB91, 0x0A97ED48, 0x0E56F0FF, 0x1011A0FA, 0x14D0BD4D, 0x19939B94, 0x1D528623,
       0xF12F560E, 0xF5EE4BB9, 0xF8AD6D60, 0xFC6C70D7, 0xE22B20D2, 0xE6EA3D65, 0xEBA91BBC, 0xEF68060B,
       0xD727BBB6, 0xD3E6A601, 0xDEA580D8, 0xDA649D6F, 0xC423CD6A, 0xC0E2D0DD, 0xCDA1F604, 0xC960EBB3,
       0xBD3E8D7E, 0xB9FF90C9, 0xB4BCB610, 0xB07DABA7, 0xAE3AFBA2, 0xAAFBE615, 0xA7B8C0CC, 0xA379DD7B,
       0x9B3660C6, 0x9FF77D71, 0x92B45BA8, 0x9675461F, 0x8832161A, 0x8CF30BAD, 0x81B02D74, 0x857130C3,
       0x5D8A9099, 0x594B8D2E, 0x5408ABF7, 0x50C9B640, 0x4E8EE645, 0x4A4FFBF2, 0x470CDD2B, 0x43CDC09C,
       0x7B827D21, 0x7F436096, 0x7200464F, 0x76C15BF8, 0x68860BFD, 0x6C47164A, 0x61043093, 0x65C52D24,
       0x119B4BE9, 0x155A565E, 0x18197087, 0x1CD86D30, 0x029F3D35, 0x065E2082, 0x0B1D065B, 0x0FDC1BEC,
       0x3793A651, 0x3352BBE6, 0x3E119D3F, 0x3AD08088, 0x2497D08D, 0x2056CD3A, 0x2D15EBE3, 0x29D4F654,
       0xC5A92679, 0xC1683BCE, 0xCC2B1D17, 0xC8EA00A0, 0xD6AD50A5, 0xD26C4D12, 0xDF2F6BCB, 0xDBEE767C,
       0xE3A1CBC1, 0xE760D676, 0xEA23F0AF, 0xEEE2ED18, 0xF0A5BD1D, 0xF464A0AA, 0xF9278673, 0xFDE69BC4,
       0x89B8FD09, 0x8D79E0BE, 0x803AC667, 0x84FBDBD0, 0x9ABC8BD5, 0x9E7D9662, 0x933EB0BB, 0x97FFAD0C,
       0xAFB010B1, 0xAB710D06, 0xA6322BDF, 0xA2F33668, 0xBCB4666D, 0xB8757BDA, 0xB5365D03, 0xB1F740B4
};

uint TSys::Crc(const void* buf, uint len, uint crc)
{
       byte* ptr = (byte*)buf;
       while(len-- > 0)
       {
             crc = c_CRCTable[ ((crc >> 24) ^ (*ptr++)) & 0xFF ] ^ (crc << 8);
       }

       return crc;
}

// 硬件实现的Crc
uint TSys::Crc(const void* buf, uint len)
{
      #ifdef STM32F4
       RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_CRC, ENABLE);
      #else
       RCC_AHBPeriphClockCmd(RCC_AHBPeriph_CRC, ENABLE);
      #endif

       CRC_ResetDR();
       // STM32的初值是0xFFFFFFFF，而软Crc初值是0
       //CRC->DR = __REV(crc ^ 0xFFFFFFFF);
       //CRC->DR = 0xFFFFFFFF;
       uint* ptr = (uint*)buf;
       len >>= 2;
       while(len-- > 0)
       {
             CRC->DR =__REV(*ptr++); // 字节顺序倒过来,注意不是位序,不是用__RBIT指令
       }
       uint crc = CRC->DR;

      #ifdef STM32F4
       RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_CRC, DISABLE);
      #else
       RCC_AHBPeriphClockCmd(RCC_AHBPeriph_CRC, DISABLE);
      #endif

       return crc;
}

static const ushort c_CRC16Table[] =
{
      0x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401,
      0xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400,
};

ushort TSys::Crc16(const void* buf, uint len, ushort crc)
{
       if (!buf || !len) return 0;

       for (int i = 0; i < len; i++)
       {
             byte b = ((byte*)buf)[i];
             crc = (ushort)(c_CRC16Table[(b ^ crc) & 0x0F] ^ (crc >> 4));
             crc = (ushort)(c_CRC16Table[((b >> 4) ^ crc) & 0x0F] ^ (crc >> 4));
       }
       return crc;
}End.

--转自