Python CRC16 test __python

CRC16 calculation. py

#! /usr/bin/python # _*_ Coding:utf-8 _*_ "" "Simple CRC16 Calculation example: CRC16 Check code calculation method is as follows: 1, initialization CRC value of 0xFFFF 2, the number of checked 1th byte With a 8-bit low or a CRC, put the result into the CRC of the low 8 bit (CRC high 8-bit unchanged) 3, CRC right 1-bit, if the removal of 0 continue to move to the right; 1CRC registers follow the generation of polynomials (value in reverse order) or (x16+x15+x2+1 <--> 0x8005 >>> 0xa0001) 4, repeat steps 3, 8 times the 1th Word Data processing 5, take the next 1 bytes of the test data, for 2, 3, 4 steps; to the entire data test complete 6, the final CRC value, high and low byte Exchange "" "# CR 
    C16 generating polynomial: x16+x15+x2+1 generator_polynomial = 0x8005 # CRC initial value is: 0xFFFF CRC = 0xFFFF def CALCULATECRC (DataArray):    "" To check that the input data is legitimate:p Aram DataArray: Data that needs to be generated for CRC: return: Legal Data Tuples "" "DataList = Dataarray.split () #以空格分割字符串得到对应字符串列表 Print (U ' input string sequence: {0} '. Format (datalist)) index = 0 Try: # converts the input string into data by a different number Sequence for index, item in Enumerate (DataList): # Print Index,item if ' 0x ' in Item.lower (). St RIP (): datalist[index] = Int (item,) Elif ' 0o ' in Item.lower (). Strip (): D Atalist[index] = Int (item,8) elif ' 0b ' in Item.lower (). Strip (): datalist[index] = Int (item,2) Else: 
        Datalist[index] = Int (item) Print (U ' corresponding sequence after successful conversion: {0} '. Format (DataList)) # Processing 1th byte data  temp = calculateonebyte (datalist.pop (0), 0xFFFF) # Recycle other byte data for data in datalist:temp = Calculateonebyte (data,temp) return temp except valueerror as Err:print (U ' {0} data {1} entered incorrectly '. Format (Index,datalist[index]). Encode (' Utf-8 ') print (ERR) # finally: # print (' Current datalist:{0} '. Format (DAT alist) def calculateonebyte (Databyte, TEMPCRC): "" Calculates the CRC value of 1-byte data:p Aram Databyte: Byte data to be computed:p Aram 
    TEMPCRC: Current CRC value: return: The new CRC value "" "# Databyte must be byte data # assert 0x00 <= databyte <= 0xFF # ditto byte data check if not 0x00 <= databyte <= 0xff:raise Exception ((U ' data: 0x{0:<02x} is not byte data [0x00-0xFF] '. Form at (databyte)). Encode (' UTF-8 ') # The Byte data root CRC the current value of the lower 8 bits is different or low_byte = (databyte ^ tempcrc) & 0X00FF # The High 8-bit value of the current CRC is unchanged RESULTCRC = (TEMPCRC & 0xff00) | Low_byte # Loop calculates 8-bit data for index in range (8): # If the minimum is 1:CRC the current value is the same as the generated polynomial or 0 continues if RESULTCRC & 0x 
            0001 = 1: #print ("[%d]: 0x%4x ^^ ^^ 0x%4x"% (index,resultcrc>>1,resultcrc^generator_polynomial)) RESULTCRC >>= 1 RESULTCRC ^= 0xa001 # 0xa001 is the 0x8005 loop right-shift 16-bit value else: # Prin T ("[{0}]: 0x{1:x} >>>> 0x{2:x}". Format (index,resultcrc,resultcrc>>1)) RESULTCRC >>= 1 return RESULTCRC if __name__ = = ' __main__ ': data_string = ' 0x01 2 0o3 ' #以16进制, 10-in, 8-input data stream Prin 
 
 
 
 
 
 T (' data: {0:s} ' corresponds to the CRC16 check code: 0x{1:04x} '. Format (DATA_STRING,CALCULATECRC (data_string))