NEC LCD8205 - MultiSync - 82" LCD Flat Panel Display Control Manual page 8

5.1.3. Check code
Check code is the Block Check Code (BCC) between the Header and the End of Message except SOH.
SOH
Reserved
Destination
Source
Type
Length
STX
Data
|
|
ETX
Check code
D = D XOR D
n+1 1
XOR: Exclusive OR
Following is an example of a Check code (BCC) calculation.
Destina
Source
SOH Reserved tion
Address
Address
01 30 41
D D D
0 1 2
Check code (BCC) D
5.1.4. Delimiter
Packet delimiter code; ASCII CR(0Dh).
Header
7
2
D
0
D
1
D
2
D
3
D
4
D
5
D
6
D
7
D
8
|
|
D
n
D P
n+1
XOR D XOR ,,, D
2 3 n
Header
Message
Message length
type
30 45 30
D D D
3 4 5
= D xor D
17 1
= 30h xor 41h xor 30h xor 45h xor 30h xor 41h
xor 02h xor 30h xor 30h xor 31h xor 30h xor 30h
xor 30h xor 36h xor 34h xor 03h
= 77h
Header
Message
Check code
6 5 4 3
2 2 2 2
P P P P
OP code
STX OP code
page
41 02 30 30 31 30
D D D D
6 7 8 9
xor D xor ... xor D
2 3
Message Check code
Delimiter
2 1 0
2 2 2
P P P
Message
Set Value
30 30 36 34
D D D D D D
10 11 12 13 14 15
xor D xor D
14 15
Delimiter
Check
code Delimiter
ETX
(BCC)
03 77 0D
D D D
16 17 18
16