BCM3212 [BOARDCOM]
DOCSIS-TM 1.1 ADVANCED CMTS MAC; DOCSIS -TM 1.1 ADVANCED CMTS MAC
| 型号： | BCM3212 |
| 厂家： | 
Broadcom Corporation. |
| 描述： | DOCSIS-TM 1.1 ADVANCED CMTS MAC |
| 文件： | 总2页 (文件大小：125K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
BCM3212
®
DOCSISTM 1.1 ADVANCED CMTS MAC
S U M M A R Y O F B E N E F I T S
F E A T U R E S
Performs DOCSISTM 1.1 MAC layer functions, including:
Hardware support for MAC-layer per-packet functions
including fragmentation, concatenation, and payload header
suppression offloads system CPU, giving higher overall system
performance.
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Fragment reassembly
Deconcatenation
Payload header suppression and expansion
56-bit DES encryption and decryption
Generation and checking of HCS and CRC
MPEG encapsulation of downstream traffic
Timestamp and SYNC message generation
Extraction of bandwidth requests and DOCSIS MAC
management messages allows software to access these
messages without examining data packets.
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Class-based queuing allows traffic prioritization:
Supports one downstream and up to six upstream channels
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High, medium, and low priority downstream queues.
High priority, low priority, request, and MAC management
upstream queues
simultaneously
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Many other downstream-to-upstream ratios can be achieved by
connecting multiple BCM3212 devices via the seamless MAP
master/slave interface
Support for carrier class redundancy via timestamp
synchronization across multiple BCM3212 devices.
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Processes up to 400,000 packets per second in the aggregate
over all upstream and downstream channels
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Supports high packet rates for maximum utilization of
available cable plant bandwidth.
Direct interface to:
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Out-of-band (OOB) generator for messaging to BCM3352-
based cable modems.
BCM3034 QAMLink® advanced universal QAM modulator
(providing downstream data rates up to 100 Mbps)
BCM3138 QAMLink® dual-channel advanced PHY burst
receiver (providing upstream data rates up to 30 Mbps per
upstream channel)
Can be remoted from external routing/classification engine for
distributed CMTS (mini fiber node) applications.
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SPI master port controls register interface to BCM3034 and
BCM3138 devices.
Packet port provides a high-throughput data interface to other
network equipment via the standard IEEE 802.3z GMII
Ethernet interface
PCI interface to external host CPU supports either 32-bit or 64-
bit operation at either 33 MHz or 66 MHz
PROPANETM packet acceleration and SMART
SPECTRUMTM technologies included for increased upstream
performance
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Packaged in an 841-pin, thermally enhanced plastic ball grid
array.
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Operates over industrial temperature range (–40 to +85
degrees C) PCI bus.
BCM3138
Dual Adv. TDMA
Receiver
Upstream
SDRAM
(PHS,
Upstream
SDRAM
(keys and
reassembly.)
BCM3138
output
BCM3138
queues)
Ethernet
Routing/
Classification
Engine
WAN
BCM3212
Advanced CMTS MAC
System
CPU
Memory
Downstream
SDRAM
BCM3034
Downstream
Modulator
(PHS,
output
queues)
Typical Application Block Diagram
O V E R V I E W
Upstream
SDRAM 1
Upstream
SDRAM 2
BCM3212
SDRAM
controller
SDRAM
controller
Post-Processing
Payload
Header
Expand
Packet
DMA
100/1000
Ethernet
MAC
Output
queue
manager
Deconcatenation
DES
decrypt
Request
filtering
Burst
DMA
Upstream
PHY i/f
Fragment
reassembly
controller
Request
DMA
MAP
parser
Out-of-
band
PHY
Out-of-
band
queue
DMA
Input
Queue
manager
Out-of-
band
Generator
PCI Bus
Interface
Unit
Timestamp
generation
Interface
In-band DOCSIS Processor
Downstream
PHY
Interface
DOCSIS
Header
creator
Payload
Header
Suppress
In-band
queue
DMA
MPEG
encapsulate
MAP
filtering
DES
Encrypt
SDRAM
controller
Downstream
SDRAM
The BCM3212 is a highly integrated CMTS MAC IC for use in
DOCSISTM 1.1 and advanced TDMA PHY-layer CMTS products. With
hardware support for concatenation parsing, fragment reassembly,
payload header suppression, and advanced TDMA PHY-layer data rates,
the BCM3212 serves as the heart of a next-generation CMTS. The
BCM3212 provides a powerful, yet cost-effective solution for a variety
of CMTS architectures.
The downstream processor accepts packets from priority queues and
performs payload header suppression, DOCSIS header creation, DES
encryption, CRC and HCS generation, MPEG encapsulation and
multiplexing, and timestamp generation on the in-band data. The
BCM3212 also includes an out-of-band generator and TDMA PHY
interface so that the BCM3212 can communicate with the out-of-band
receiver of the BCM3352 cable modem device for control of power
management functions.
The BCM3212 is based on sophisticated hardware processing engines
for both the upstream and downstream paths. To achieve upstream
throughput of 200 000 packets per second, the upstream processor design
is segmented and uses two banks of SDRAM to minimize latency on the
internal buses. The Upstream Processor performs DES decryption,
fragment reassembly, deconcatenation, payload header expansion,
PROPANETM packet acceleration, upstream MIB statistic gathering,
and priority queuing for the resultant packets. Each upstream queue can
be independently configured to output packets to either the PCI or GMII
interface. DOCSIS MAC management messages and bandwidth requests
are extracted and queued separately from data packets so that they are
readily available to the system controller.
All configuration and management of the BCM3212 is done via the PCI
interface. The PCI interface accommodates either 32-bit or 64-bit hosts
operating at either 33 MHz or 66 MHz. The 100/1000 Ethernet MAC
provides a standard interface (IEEE 802.3z GMII or MII) for
transporting packets to and from the BCM3212.
A single BCM3212 supports the association of 1 downstream channel
with up to 6 upstream channels. By connecting multiple BCM3212 chips
via the seamless master/slave interface, many other ratios may be
achieved, including 2 downstream to 12 upstream (2:12) and 1
downstream to 24 upstream (1:24). In multiple downstream
configurations, upstream channels can be remotely provisioned to be
associated with 1 of 2 downstream channels to enable load shifting.
Broadcom®, the pulse logo, and Connecting everything® are trademarks of Broadcom Corporation and/
or its subsidiaries in the United States and certain other countries. All other trademarks mentioned are the
property of their respective owners.
®
BROADCOM CORPORATION
16215 Alton Parkway, P.O. Box 57013
Irvine, California 92619-7013
Phone: 949-450-8700
Fax: 949-450-8710
E-mail: info@broadcom.com
Web: www.broadcom.com
© 2004 by BROADCOM CORPORATION. All rights reserved.
3212-PB04-R
07/01/04
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