SCC Ethernet Mode
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 25-11
25.10 SCC Ethernet Address Recognition

The Ethernet controller can filter received frames based on different addressing types—physical

(individual), group (multicast), broadcast (all-ones group address), and promiscuous. The difference

between an individual address and a group address is determined by the I/G bit in the destination address

field. A flowchart for address recognition on received frames is shown in Figure25-4.

In the physical type of address recognition, the Ethernet controller compares the destination address field

of the received frame with the user-programmed physical address in PADDR1. Address recognition can

be performed on multiple individual addresses using the IADDR1–4 hash table.

Figure 25-4. Ethernet Address R ecognition Flowchart

In group address recognition, the controller determines whether the group address is a broadcast address.

If broadcast addresses are enabled, the frame is accepted, but if the group address is not a broadcast

Check Address
I/G Address
?
Hash_Search
False
G
True
True
Multiple IND
?
Broadcast
Address
Use Indicated
Table
Hash Search
Use Group
Table
Match
?
Match
?
Receive Frame
Ignore REJECT
Receive Frame
Ignore REJECT
Match
?
Receive Frame
Ignore REJECT
PROMISC
?
Start Receive
Discard Frame if REJECT
Discard Frame
is Asserted
I
True
True
False
False True
True
FalseFalse
?
Broadcast
Enabled
?
True Fal se
False
Multiple Individual
Addresses
Single
Address