BCM3212 Datasheet, PDF (1/2 Pages) Broadcom Corporation. – DOCSIS-TM 1.1 ADVANCED CMTS MAC

BCM3212
®
DOCSIS^TM 1.1 ADVANCED CMTS MAC
FEATURES
• ^{Performs DOCSISTM 1.1 MAC layer functions, including:}
• 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
• ^{Supports one downstream and up to six upstream channels}
simultaneously
• Many other downstream-to-upstream ratios can be achieved by
connecting multiple BCM3212 devices via the seamless MAP
master/slave interface
• ^{Processes up to 400,000 packets per second in the aggregate}
over all upstream and downstream channels
• ^{Direct interface to:}
• 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)
• ^{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
•
PROPANE^TM packet acceleration and SMART
SPECTRUM^TM technologies included for increased upstream
performance
SUMMARY OF BENEFITS
• Hardware support for MAC-layer per-packet functions
including fragmentation, concatenation, and payload header
suppression offloads system CPU, giving higher overall system
performance.
• Extraction of bandwidth requests and DOCSIS MAC
management messages allows software to access these
messages without examining data packets.
• Class-based queuing allows traffic prioritization:
• High, medium, and low priority downstream queues.
• High priority, low priority, request, and MAC management
upstream queues
• Support for carrier class redundancy via timestamp
synchronization across multiple BCM3212 devices.
• Supports high packet rates for maximum utilization of
available cable plant bandwidth.
• Out-of-band (OOB) generator for messaging to BCM3352-
based cable modems.
• Can be remoted from external routing/classification engine for
distributed CMTS (mini fiber node) applications.
• SPI master port controls register interface to BCM3034 and
BCM3138 devices.
• Packaged in an 841-pin, thermally enhanced plastic ball grid
array.
• Operates over industrial temperature range (–40 to +85
degrees C) PCI bus.
BCM3138
Dual Adv. TDMA
Receiver
BCM3138
BCM3138
Upstream
SDRAM
(keys and
reassembly.)
Upstream
SDRAM
(PHS,
output
queues)
Ethernet
Routing/
Classification
Engine
WAN
BCM3212
Advanced CMTS MAC
System
CPU
BCM3034
Downstream
Modulator
Downstream
SDRAM
(PHS,
output
queues)
Memory
Typical Application Block Diagram