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Broadcom BCM3300Cable Modem IC

Broadcom Announces World's First Single-Chip Cable Modem Solution

The manufacturer says . . .

Chipcenter's Paul McGoldrick says . . .

Broadcom Corporation, a leading developer of integrated circuits enabling high-speed broadband communications to the home and business, today announced the availability of the industry's first single-chip communications solution for cable modems. Broadcom's integration of all of the cable modem media access control (MAC) and physical layer (PHY) transmission functionality into a single chip, will allow its customers and end-users to substantially benefit from the lower cost, smaller size and improved features of next-generation cable modems. Cable modems with Broadcom's single-chip solution will also allow cable operators to provide current and future subscribers with advanced services, including telephony over the cable network. This cable modem technology will enable existing coax cable networks to deliver data, digital video, telephony and Internet access at speeds up to 56 megabits-per-second (Mbps), which is 1000 times faster than standard 56k voice-band modems.

"Broadcom's single-chip solution represents a significant milestone in the evolution of cable modems," said Dr. Henry Nicholas, Broadcom's President and CEO. "Developing an entire communications system on a chip allows us to drive down costs while increasing functionality for our customers. This chip will enable manufacturers to deliver advanced, standards-based cable modems at very attractive consumer price points. Cable operators are now in a very competitive position to provide high-speed Internet access over cable, and, by offering features such as telephony over cable, they can generate profitable new revenue streams."

Next-Generation Cable Modems

The new Broadcom QAMLink cable modem chip, the BCM3300, is fully compliant with the Multimedia Cable Network Systems (MCNS) Data Over Cable Service Interface Specification (DOCSIS) version 1.0 and will support next-generation modems with the following advanced features:

Advanced Quality of Service (QoS) capabilities, which allow cable operators to offer multiple access speeds at different price points.

Fragmentation, which supports the ability to provision constant bit rate services for applications such as cable telephony and videoconferencing.

Support for multiple destination addresses and multicast filters to support "push services," such as stock tickers, news, and sports scores, by cable operators.

Support for North American, European and Asian physical layer transmission standards.

"With the BCM3300, Broadcom has leapfrogged the integration path of its competitors to retain its leadership position in cable modem silicon. With its additional features, high level of integration, and low price, this chip paves the way for not only the next generation of less expensive cable modems, but a whole new class of interactive devices that utilize the cable network," said Allen Leibovitch, Senior Analyst, Semiconductor Research at IDC.

Broadcom's Cable Modem Roadmap

The single-chip solution is the latest milestone in Broadcom's cable modem roadmap and integrates the functions of the current cable modem chip-set -- the BCM3116 QAMLink Demodulator, BCM3037 QAMLink Burst Modulator, and BCM3220 QAMLink MAC. Broadcom will continue to produce these chips, which are currently shipping in production volumes for MCNS/DOCSIS 1.0 cable modems.

BCM3300's Feature Set

Broadcom's BCM3300 integrates a 64/256-QAM receiver, a 4/16-QAM transmitter and an MCNS/DOCSIS 1.0 MAC with enhancements into a single chip. The integrated receiver supports downstream data rates up to 56 Mbps, and the integrated transmitter supports upstream data rates up to 20 Mbps. The integrated MAC supervises the upstream and downstream functions as specified by the MCNS/DOCSIS 1.0 MAC protocol, including advanced QoS and fragmentation capability. The integrated MAC also includes baseline privacy encryption/decryption for Internet security with 56-bit DES Cipher Block Chaining.

Broadcom has incorporated many advanced features into the BCM3300. The device integrates a multi-mode ITU-T J.83 Annex A/B/C compatible forward error correction (FEC) decoder in the receiver and a programmable MCNS/DVB/DAVIC FEC encoder in the transmitter. A digital demodulator, Nyquist filters, tracking loops, and an adaptive-decision feedback equalizer are incorporated into the receiver, and a pre-equalizer filter is in the transmitter.

The chip interfaces to multiple low-cost, industry-standard CPUs, including the MIPS CPU, an architecture that was recently licensed by Broadcom. For improved performance and ease of manufacturing, Broadcom also incorporated an analog front-end into the BCM3300. The downstream receiver includes a programmable gain amplifier and a 10-bit analog-to-digital (A/D) converter, and the upstream transmitter incorporates a 10-bit digital-to-analog (D/A) converter and a programmable attenuator.

Supporting Reference Design

To facilitate the design of cable modems based on the BCM3300, Broadcom has developed the BCM93300 cable modem reference design. The BCM93300 is a fully operational cable modem reference design that supports all of the MCNS/DOCSIS 1.0 PHY and MAC protocol functions, as well as the advanced features incorporated in the BCM3300. The BCM93300 provides interfaces for 10Base-T Ethernet, Universal Serial Bus (USB), Voice over IP (the ability to send voice over the cable network using Internet Protocol) and video teleconferencing implementations. In addition to these interfaces, the reference design incorporates Broadcom's BCM3300, an RF Tuner with diplex filter, the CPU and memory onto a compact 6 x 8 inch board, thereby reducing the size and complexity of cable modems by one third.

It has looked for the last couple of months that Broadcom would be the first to get the single chip product to market, and that it has done. The BCM3300 combines the current three chips into one device and gets the price closer to the market needs. With the addition of other features that they have not been afraid to add they have neatly leapfrogged the nearest competition and set themselves up to be ready for the second generation of modems just a couple of months before terrestrial DTV transmissions begin.

The satellite industry is gearing itself for a boost in business with the launch of DTV and before most of the major cable systems get converted to digital. They believe they will then have a really hard time expanding business with the transponder limitations that they have. Cable operators, however, with large investments from outside their industry will be quickly developing two-way systems in the major population centers. Provided the operators spend less time debating and hair-splitting on "must-carry" rules and their applicability to DTV services, the additional features that can be made available may woo quite a large proportion of customers. In the UK, for example, there has been a quite dramatic switch by users to taking the option to having their telephone "on the cable" since it has become available.

With the additional RF tuner needed, power, CPU and memory together with the packaging the manufacturing cost of the cable modem with this part is probably down to about $62, but that is still too high for the $199 box that the industry needs on your local Circuit City's shelf. To achieve that number the IC will have to be priced at around $25.

The BCM3300 is sampling now; it is packaged in a 256-pin BGA and is priced at $50 in 10,000-piece lots.

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