DLPU057A March 2018 – April 2022
This byte is used for verifying the integrity of the command packet. It is the sum of all the bytes in the current packet (from Command Byte to Data[n]).
For the command packet send by master,
Checksum = (Byte1 + Byte2 + … + Byten + Byten+1 + Byten+2) MOD 0x100
Where n = length of data (see Figure 1-3).
Please note that START_CHARACTER is not included in the checksum.
The MOD function is defined as,
R = a mod b
Where,
a = dividend
b = divisor
R = Remainder on division of a by b.
For the response packet send by slave for a read command (Figure 1-6), the checksum is computed as the sum of all bytes from Response Byte to Data[m]. This is shown below:
Checksum = (Bytek + Bytek+1 + … + Bytek+m+1) MOD 0x100
Where m = length of data returned by slave
k = byte index of response byte.