Motorola MPC8260 - Manual (Page 680)

24-12 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part IV. Communications Processor Module
Figure 24-4. Ethernet Address Recognition 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 address, address recognition can be performed on multiple
group addresses using the GADDRn hash table. In promiscuous mode, the controller
receives all incoming frames regardless of their address, unless REJECT is asserted.
If an external CAM is used for address recognition, select promiscuous mode; the frame
can be rejected by asserting REJECT while the frame is being received. The on-chip
address recognition functions can be used in addition to the external CAM address
recognition functions.
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
False False
?
Broadcast
Enabled
?
True False
False
Multiple Individual
Addresses
Single
Address