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Electronic Design

Hot RISC Processor Enables Consumer Voice Over Cable

With Voice over Internet Protocol (VoIP) becoming more popular, cable operators are looking for a low-cost way to provide it to existing customers. Broadcom’s BCM3368 voiceover- cable modem system-on-a-chip lets set-top-box vendors incorporate all the usual functions of a DOCSIS-compliant cable box, but now with VoIP capability and more.

Broadcom’s VoIP firmware runs on the Viper enhanced RISC processor. Thanks to its speed, architecture, and DSP extensions, multiline voice solutions can be implemented without the costly and complicated dual-processor, dual-memory architecture other VoIP modems use. The chip’s integration reduces the component count by over 20% for a more cost-effective solution. Also, Viper RAM and flash are external to the chip, which supports the connection to two SLICs. This enables the use of two standard telephones for VoIP.

The BCM3368 fully complies with DOCSIS 2.0 for customer premises equipment. It accepts the analog IF input from the cable tuner and digitizes the signal for further procession. The chip also offers advanced capabilities for a variety of solutions, including PacketCable-compliant NCS call protocol, Session Initiated Protocol (SIP), and the emerging cellular convergence in voice-over-cable applications. So, the BCM3368 will support cell phones with VoIP on Wi-Fi as a home extension.

Additionally, it’s the first voice-over-cable modem to incorporate ICSA Labs-certified firewall technology, which prevents hackers from disrupting voice service. Also, the Viper processor can run advanced CableHome and gateway protocols. The chip supports a range of peripheral interfaces, including multiport Ethernet, ISB, Bluetooth, storage devices, subscriber identification module cards, and wireless local-area network, including the forthcoming 802.11n. The BCM3368 comes in a 426-pin PBGA package. It costs $25 in 100,000-unit lots.

Broadcom Inc.

TAGS: Digital ICs
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