GE Hydran 201i - Page 245

Page 245
Hydran* 201i Instruction Manual
MA-033 Rev. 14.0, 12-Nov-18
3.
0 --> j
4.
Di (+) Alow --> Alow
5.
j + 1 --> j
6.
shr (A)
7.
Is there a
carry?
No: go to 8; Yes: G (+) A --> A and
continue
8.
Is j = 8?
No: go to 5; Yes: continue
9.
i + 1 --> i
10.
Is i = N?
No: go to 3; Yes: continue
11.
A --> CRC
Table J - 2 CRC-16 Algorithm
Symbol
Description
-->
Data transfer
A
16-bit working register
Alow
Low-order byte of A
Ahigh
High-order byte of A
CRC
16-bit CRC-16 result
i,j
Loop counters
(+)
(+) logical Exclusive Or operator
N
Total number of data bytes
Di
i-th data byte (i = 0 to N-1)
G
16-bit characteristic polynomial = 1010000000000001 (binary)
with MSbit dropped and bit order reversed
shr (x)
Right shift operator (the LSbit of x is shifted into a carry flag, a “0”