Functional Description

The effectiveness of the hash table declines as the number of addresses increases.

The hash table registers must be initialized by the user. The CRC32 polynomial to use in computing the hash is:

X32 + X26 + X23 + X22 + X16 + X12 + X11 + X10 + X8 + X7 + X5 + X4 + X2 + X + 1

A table of example Destination Addresses and corresponding hash values is included below for reference.

Table 17-7. Destination Address to 6-Bit Hash

48-bit DA

6-bit Hash (in

Hash Decimal

hex)

Value

 

 

 

 

65:ff:ff:ff:ff:ff

0x0

0

 

 

 

55:ff:ff:ff:ff:ff

0x1

1

 

 

 

15:ff:ff:ff:ff:ff

0x2

2

 

 

 

35:ff:ff:ff:ff:ff

0x3

3

 

 

 

b5:ff:ff:ff:ff:ff

0x4

4

 

 

 

95:ff:ff:ff:ff:ff

0x5

5

 

 

 

d5:ff:ff:ff:ff:ff

0x6

6

 

 

 

f5:ff:ff:ff:ff:ff

0x7

7

 

 

 

db:ff:ff:ff:ff:ff

0x8

8

 

 

 

fb:ff:ff:ff:ff:ff

0x9

9

 

 

 

bb:ff:ff:ff:ff:ff

0xa

10

 

 

 

8b:ff:ff:ff:ff:ff

0xb

11

 

 

 

0b:ff:ff:ff:ff:ff

0xc

12

 

 

 

3b:ff:ff:ff:ff:ff

0xd

13

 

 

 

7b:ff:ff:ff:ff:ff

0xe

14

 

 

 

5b:ff:ff:ff:ff:ff

0xf

15

 

 

 

27:ff:ff:ff:ff:ff

0x10

16

 

 

 

07:ff:ff:ff:ff:ff

0x11

17

 

 

 

57:ff:ff:ff:ff:ff

0x12

18

 

 

 

77:ff:ff:ff:ff:ff

0x13

19

 

 

 

f7:ff:ff:ff:ff:ff

0x14

20

 

 

 

c7:ff:ff:ff:ff:ff

0x15

21

 

 

 

97:ff:ff:ff:ff:ff

0x16

22

 

 

 

a7:ff:ff:ff:ff:ff

0x17

23

 

 

 

17-14

MCF5282 User’s Manual

MOTOROLA

Page 370
Image 370
Motorola MCF5282, MCF5281 user manual Destination Address to 6-Bit Hash, Bit DA Bit Hash Hash Decimal Hex Value