BCM3212 features upstream analog inputs bcm3138 dual adv. tdma receiver bcm3138 bcm3138 upstream sdram (keys and reassembly.) upstream sdram (phs, output queues) routing/ classification engine ethernet system cpu memory pci bus BCM3212 advanced cmts mac downstream sdram (phs, output queues) bcm3034 downstream modulator downstream analog inputs wan typical application block diagram 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 (?0 to +85 degrees c) pci bus. summary of benefits BCM3212 docsis tm 1.1 advanced cmts mac product brief BCM3212 performs docsis tm 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
the BCM3212 is a highly integrated cmts mac ic for use in docsis tm 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 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, propane tm 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. 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 bcm3352 cable modem devices out-of- band receiver for control of power management functions. 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 one downstream channel with up to six upstream channels. by connecting multiple BCM3212 chips via the seamless master/slave interface, many other ratios may be achieved, including two downstreams to 12 upstreams (2 12) and one downstream to 24 upstreams (1 24). in multiple-downstream configurations, upstream channels can be remotely provisioned to be associated with one of two downstreams to enable load shifting. BCM3212 overview BCM3212 in-band docsis processor post-processing sdram controller fragment reassem bly controller payload header expand packet dma output queue manager request dm a 100/1000 ethernet mac pci bus interface unit upstream sdram 1 upstream sdram 2 input queue mana ger downstream sdram payload header suppress docsis header creator des encryp t map filtering map parse r mpeg encapsulate downstream phy interface timestamp generatio n out-of- band generator out-of- band phy interfac e in-band queue dma out-of- band queue dma pci interface upstream phy i/f des decryp t request filtering burst dma sdram controller sdram controll er packet port/gmii from bcm 3138 to bcm 3034 deconcatenation BCM3212 simplified block diagram phone: 949-450-8700 fax: 949-450-8710 email: info@broadcom.com web: www.broadcom.com broadcom , the pulse logo , qamlink , propane tm and connecting everything tm are trademarks of broadcom corporation and/or its subsidiaries in the united states and certain other countries. docsis tm is a trademark of cable television laboratories, inc. smart spectrum tm is a trademark of data-linc group. all other trademarks are the property of their respective owners. broadcom corporation 16215 alton parkway, p.o. box 57013 irvine, california 92619-7013 ? 2002 by broadcom corporation. all rights reserved. 3212-pb02-r-4.29.02
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