CHECKSUM CHECKSUMXOR

CHECKSUM CHECKSUMXOR

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Action

Returns a checksum of a string.

 

 

Syntax

PRINT Checksum(var)

b = Checksum(var)

b = ChecksumXOR(var)

 

 

Remarks

Var

A string variable.

B

A numeric variable that is assigned with the checksum.

 

 

The checksum is computed by counting all the bytes of the string variable.

The checksumXOR is computed by Xor-ing all the bytes of the string variable.

Checksums are often used with serial communication.

The checksum is a byte checksum. The following VB code is equivalent :

 

Dim Check as Byte

Check = 0

For x = 1 To Len(s$)

  Check = check + ASC(mid$(s$,x,1))

Next

 

The following VB code is equivalent for ChecksumXOR

Dim Check as Byte

Check = 0

For x = 1 To Len(s$)

  Check = check XOR ASC(mid$(s$,x,1))

Next

 

 

See also

CRC8 , CRC16 , CRC32 , CRC16UNI, CRCMB

 

 

Example

$regfile = "m48def.dat"                                   ' specify the used micro

$crystal = 8000000                                         ' used crystal frequency

$baud = 19200                                               ' use baud rate

$hwstack = 32                                               ' default use 32 for the hardware stack

$swstack = 10                                               ' default use 10 for the SW stack

$framesize = 40                                             ' default use 40 for the frame space

 

Config Com1 = Dummy , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0

 

 

Dim S As String * 10                                       'dim variable

S = "test"                                                 'assign variable

Print Checksum(s)                                         'print value (192)

End