L-ET4148-50C-DB LSI, L-ET4148-50C-DB Datasheet - Page 33

• Manufacturer Part Number: L-ET4148-50C-DB
• Manufacturer: LSI

Specifications of L-ET4148-50C-DB

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Preliminary Data Sheet
April 2006
Agere Systems Inc.
Functional Description
Retrieval
Two processes per queue operate in parallel during packet retrieval. One process manages a bandwidth shaper
function while the other performs arbitration and actually retrieves the stored packet.
DEALLOCATE BUFFERS
TOKEN BUCKET ACCUMULATOR
PROPORTIONAL TO PORT SPEED
WAIT FOR PERIOD THAT IS
CONGESTION
CONGESTION
THRESHOLD
CONGESTION
THRESHOLD
THRESHOLD
CROSSED?
CROSSED?
CROSSED?
GLOBAL
LOCAL
LOCAL
ADD CREDIT TO
N
N
START
Y
Y
Single-Chip 48 x 1 Gbit/s + 2 x 10 Gbits/s Layer 2+ Ethernet Switch
(continued)
PORTS UNCONGESTED
PORT UNCONGESTED
DECLARE CURRENT
DECLARE ALL
Figure 13. Retrieval Processes
Agere Systems - Proprietary
ARBITRATE AGAINST OTHER QUEUES
TOKEN BUCKET ACCUMULATOR
OF THE SAME TRANSMIT PORT
SUBTRACT PACKET LENGTH
Y
VLAN ENCAPSULATION
DELIVER PACKET TO
ACCUMULATOR > 0?
RETRIEVE PACKET
RETRIEVAL FOR
PACKET?
START
DONE
LAST
Y
N
N
ET4148-50
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