CDK8920A View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
'CDK8920A' PDF : 144 Pages View PDF
CS8920A
Destination Address (DA)
from incoming frame
CS8920A
CRC
Logic
(MSB) 32-bit CRC value (LSB)
6-bit Hash Register (HR)
[Hash Table Index]
to
Hashed
1
bit
64-input
OR gate
6-to-64 decoder
64
64-bit Logical Address Filter (LAF)
Written into PacketPage base + 150h
Figure 5.5. Hash Filter Operation
Address
Type of
Received
Frame
Individual
Address
Erred
Frame?
no
no
Passes
Hash
Filter?
Bits F-A
Contents of RxEvent
Bit 9
Hashed
yes
Hash Table Index
1
no ExtraRuntCRCBroadcastIndividual
0
Bit 8
RxOK
1
1
Bit 6
IAHash
1
0
DataErrorAdr
yes don’t care ExtraRuntCRCBroadcastIndividual
0
0
0
DataErrorAdr
Multicast
no
yes
Hash table index
1
1
0
Address
no
no ExtraRuntCRCBroadcastIndividual
0
1
0
DataErrorAdr
yes don’t care ExtraRuntCRCBroadcastIndividual
0
0
0
DataErrorAdr
Broadcast no yes (Note 1) ExtraRuntCRCBroadcastIndividual
1
1
0
Address
DataErrorAdr
(actual value X00010)
no
no ExtraRuntCRCBroadcastIndividual
0
1
0
DataErrorAdr
yes don’t care ExtraRuntCRCBroadcastIndividual
0
0
0
DataErrorAdr
NOTES:
1. Broadcast frames are accepted as Multicast frames if and only if all the following conditions are
met simultaneously:
a) the Logical Address Filter is programmed as: (MSB) 0000 8000 0000 0000h (LSB). Note that
this LAF value corresponds to a Multicast Addresses of both all 1s and 03-00-00-00-00-01.
b) The Rx Control Register (register 5) is programmed to accept IndividualA, MulticastA, RxOK-only,
and the following address filters were enabled: IAHashA and BroadcastA.
2. NOT (Note 1).
3. This frame is accepted if the promiscuous accept bit is set.
4. This frame is accepted if either promiscuous accept or broadcast accept bit are set.
Table 5.7. Contents of RxEvent Upon Various Conditions
DS238PP2
97
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