vb的crc(ccitt)算法

vb的crc(ccitt)算法 vb的crc(ccitt)算法 分类: IT技术 2006-03-13 09:31 'CRC-16 校验有多种模式，上位端的必须与下位机一致。例如，同样对于 {0x31,0x32,0x33,0x34,0x35,0x36} 各种模式的结果为: 'CRC-16 0xBB3D 'CRC-16 (Modbus) 0x4B37 'CRC-16 (Sick) 0x56A6 'CRC-CCITT (XModem) 0x31C3 'CRC-CCITT (0xFFFF) 0x29B1 'CRC-CCITT (0x1D0F) 0xE5CC 'CRC-CCITT (Kermit) 0x8921 'CRC-DNP 0x82EA '实际上，需要确定的就是多项式是初始值。 'CRC-16 0x8005 x16 + x15 + x2 + 1 'CRC-CCITT 0x1021 x16 + x12 + x5 + 1 'CRC-DNP 0x3D65 x16 + x13 + x12 + x11 + x10 + x8 + x6 + x5 + x2 + 1 在网上找遍了没有vb的ccitt版本的crc算法，所以，自己写了一个， 供大家鉴赏: Function CRC_CCITT(data() As Byte) As String Dim CRC16Lo As Byte, CRC16Hi As Byte Dim CL As Byte, CH As Byte Dim SaveHi As Byte, SaveLo As Byte Dim i As Integer Dim Flag As Integer CRC16Lo = &HFF CRC16Hi = &HFF CL = &H21 CH = &H10 For i = 0 To UBound(data) CRC16Hi = CRC16Hi Xor data(i) For Flag = 0 To 7 SaveHi = CRC16Hi SaveLo = CRC16Lo If CRC16Hi * 2 > &HFF Then CRC16Hi = CRC16Hi * 2 - &H100 Else CRC16Hi = CRC16Hi * 2 End If If CRC16Lo * 2 > &HFF Then CRC16Lo = CRC16Lo * 2 - &H100 Else CRC16Lo = CRC16Lo * 2 End If If ((SaveLo And &H80) = &H80) Then CRC16Hi = CRC16Hi Or &H1 End If If ((SaveHi And &H80) = &H80) Then CRC16Hi = CRC16Hi Xor CH CRC16Lo = CRC16Lo Xor CL End If Next Flag Next i Dim ReturnData(1) As Byte ReturnData(0) = CRC16Hi TextBox1.Text = TextBox1.Text & vbCrLf & CStr(CRC16Hi) ReturnData(1) = CRC16Lo TextBox1.Text = TextBox1.Text & vbCrLf & CStr(CRC16Lo) CRC_CCITT = ReturnData End Function 一并把c的代码也贴出来: unsigned int CCRCDlg::Cal_Crc(unsigned char *data_to_cal_crc, int len) { unsigned int crc; unsigned char i; crc = 0xFFFF; while (len-- != 0) { crc = crc ^ ((unsigned int)*data_to_cal_crc++ << 8); for (i = 0; i < 8; ++i) { if (crc & 0x8000) crc = (crc << 1) ^ 0x1021; else crc = crc << 1; } } return (crc & 0xFFFF); } '我要算的是CRC-CCITT的结果,CCITT的 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 是反相多项式为 &H8408 '多项式为&H1021 '校验多项式为G(X) = X^16 + X^12 + X^5 + 1. Function CRC_CCITT_0(Data() As Byte) As String Dim crc As Long Dim I As Byte, j As Integer Dim crch As String, crcl As String crc = 0 For j = LBound(Data) To UBound(Data) - 1 I = &H80 While (I <> 0) If (crc And &H8000) <> 0 Then crc = crc * 2 crc = crc Xor &H1021 Else crc = crc * 2 If (Data(j) And I) <> 0 Then crc = crc Xor &H1021 End If I = I / 2 If crc > 65536 Then crc = crc - 65536 End If Wend Next j crch = (Fix(crc / 256)) '十六进制编码数字 HEX() If Len(crch) = 1 Then crch = "0" & crch crcl = (crc Mod 256) If Len(crcl) = 1 Then crcl = "0" & crcl CRC_CCITT_0 = crch & " " & crcl TxCommData(131) = crch '保存CRC数据 BA 64 TxCommData(132) = crcl End Function '我要算的是CRC-CCITT的结果 '校验多项式为G(X) = X^16 + X^12 + X^5 + 1. Function CRC_CCITT_1(Data() As Byte) As String Dim CRC16Lo As Byte, CRC16Hi As Byte Dim CL As Byte, CH As Byte Dim SaveHi As Byte, SaveLo As Byte Dim I As Integer Dim Flag As Integer CRC16Lo = &HFF CRC16Hi = &HFF CL = &H21 '与CCITT特定的&H1021异或 CH = &H10 For I = 0 To UBound(Data) CRC16Hi = CRC16Hi Xor Data(I) For Flag = 0 To 7 SaveHi = CRC16Hi SaveLo = CRC16Lo If CRC16Hi * 2 > &HFF Then CRC16Hi = CRC16Hi * 2 - &H100 Else CRC16Hi = CRC16Hi * 2 End If If CRC16Lo * 2 > &HFF Then CRC16Lo = CRC16Lo * 2 - &H100 Else CRC16Lo = CRC16Lo * 2 End If If ((SaveLo And &H80) = &H80) Then CRC16Hi = CRC16Hi Or &H1 End If If ((SaveHi And &H80) = &H80) Then CRC16Hi = CRC16Hi Xor CH CRC16Lo = CRC16Lo Xor CL End If Next Flag Next I 'Dim ReturnData(1) As Byte 'ReturnData(0) = CRC16Hi 'TextBox1.Text = TextBox1.Text & vbCrLf & CStr(CRC16Hi) 'ReturnData(1) = CRC16Lo 'TextBox1.Text = TextBox1.Text & vbCrLf & CStr(CRC16Lo) 'CRC_CCITT = ReturnData TxCommData(131) = CRC16Hi '保存CRC数据 TxCommData(132) = CRC16Lo End Function '****************************1(计算法**多项式码 &HA001***************************************** '多项式为X(16)+X(15)+X(2)+1 '***********************计算法就是依据CRC校验码的产生原理来 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 程序************** Function CRC16_0(Data() As Byte) As String Dim CRC16Lo As Byte, CRC16Hi As Byte 'CRC寄存器 Dim CL As Byte, CH As Byte '多项式码&HA001 Dim SaveHi As Byte, SaveLo As Byte Dim I As Integer Dim Flag As Integer CRC16Lo = &HFF CRC16Hi = &HFF CL = &H1 CH = &HA0 For I = 0 To UBound(Data) CRC16Lo = CRC16Lo Xor Data(I) '每一个数据与CRC寄存器进行异或 For Flag = 0 To 7 SaveHi = CRC16Hi SaveLo = CRC16Lo CRC16Hi = CRC16Hi \ 2 '高位右移一 CRC16Lo = CRC16Lo \ 2 '低位右移一位 If ((SaveHi And &H1) = &H1) Then '如果高位字节最后一位为1 CRC16Lo = CRC16Lo Or &H80 '则低位字节右移后前面补1 End If '否则自动补0 If ((SaveLo And &H1) = &H1) Then '如果LSB为1，则与多项式码进行异或 CRC16Hi = CRC16Hi Xor CH CRC16Lo = CRC16Lo Xor CL End If Next Flag Next I 'Dim ReturnData(1) As Byte 'ReturnData(0) = CRC16Hi 'CRC高位 'ReturnData(1) = CRC16Lo 'CRC低位 'CRC16 = ReturnData TxCommData(131) = CRC16Hi '保存CRC数据 TxCommData(132) = CRC16Lo End Function '多项式为X(16)+X(15)+X(2)+1 Function CRC16_1(ByRef cmdstring() As Byte, ByVal j As Integer) Dim Data As Integer Dim I As Integer Dim HiByte, LoByte, Addressreg_crc As Integer Addressreg_crc = &HFFFF For I = 0 To j Addressreg_crc = Addressreg_crc Xor cmdstring(I) For j = 0 To 7 Data = Addressreg_crc And &H1 If Data Then Addressreg_crc = Int(Addressreg_crc / 2) Addressreg_crc = Addressreg_crc And &H7FFF Addressreg_crc = Addressreg_crc Xor &HA001 Else Addressreg_crc = Addressreg_crc / 2 Addressreg_crc = Addressreg_crc And &H7FFF End If Next j Next I If Addressreg_crc < 0 Then Addressreg_crc = Addressreg_crc - &HFFFF0000 End If HiByte = Addressreg_crc And &HFF LoByte = (Addressreg_crc And &HFF00) / &H100 'Dim ReturnData(1) As Byte 'ReturnData(0) = CRC16Hi 'CRC高位 'ReturnData(1) = CRC16Lo 'CRC低位 'CRC16 = ReturnData TxCommData(131) = HiByte '保存CRC数据 TxCommData(132) = LoByte End Function '****************************2(查 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 法 ************************************** '多项式为X(16)+X(15)+X(2)+1 '***********************查表法的优缺点与计算法的正好相反******************** Private Function CRC16_2(Data() As Byte) As String Dim CRC16Hi As Byte Dim CRC16Lo As Byte CRC16Hi = &HFF CRC16Lo = &HFF Dim I As Integer Dim iIndex As Long For I = 0 To UBound(Data) iIndex = CRC16Lo Xor Data(I) CRC16Lo = CRC16Hi Xor GetCRCLo(iIndex) '低位 处理 CRC16Hi = GetCRCHi(iIndex) '高位 处理 Next I 'Dim ReturnData(1) As Byte 'ReturnData(0) = CRC16Hi 'CRC高位 'ReturnData(1) = CRC16Lo 'CRC低位 'CRC16 = ReturnData TxCommData(131) = CRC16Hi TxCommDa End Function 'CRC低位字节值表 Function GetCRCLo(ind As Long) As Byte GetCRCLo = Choose(ind + 1, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, _ &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40, &H1, &HC0, &H80, &H41, &H1, &HC0, &H80, &H41, &H0, &HC1, &H81, &H40) End Function 'CRC高位字节值表 Function GetCRCHi(ind As Long) As Byte GetCRCHi = Choose(ind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nd Function '================================================================================================================================================================================================================================================================= '=================================================================================================================================================================================================================================================================