C-Cube adds cable-modem technology

Set-top and DVD-chip manufacturer C-Cube Microsystems is expanding its business into cable-modem technology with the MultiLynx family of integrated cable-modem chips. The Milpitas, Calif.-based company has introduced both a chip designed for stand-alone cable modems, the MultiLynx CL2161, and a modem chip designed specifically for set-top boxes, the CL2151.

Both chips will be demonstrated at the Western Cable show in Los Angeles next week. The chips should start sampling in the beginning of 2001 and make their way into commercial products by mid-to-late 2001. The CL2161 model will be priced at $25 in quantities of 100,000; the CL2151 set-top model will be priced at $30.

C-Cube's foray into cable modems is the result of its January 1999 acquisition of TV/Com International's set-top silicon division, according to C-Cube Strategic Marketing Manager Brian Johnson.

"A lot of our customers in the set-top space are looking for a complete solution," says Johnson. "That's why we picked up TV/Com. They've got a very solid team in San Diego that we've integrated with, and the MultiLynx family is the fruit of that effort into the communications part of the set-top box."

Instead of simply building a straight QAM demodulator, C-Cube decided to "integrate the whole cable front end of the set-top box."

The CL2161 supports the DOSCIS, EuroDOSCIS and DVB in-band cable-modem standards. It integrates a QAM demodulator with analog-to-digital converter for the downstream channel, and a QAM/QPSK modulator with D-to-A converter for the return. An included communications processor acts as the host CPU and supports voice-over-IP (VoIP) functionality.

The CL2151 has similar cable-modem functionality but adds a second QAM demodulator that could enhance a set-top's video functionality. When used in conjunction with C-Cube's new 9600 MPEG-11 decoder chip, the second QAM demodulator will allow a digital set-top equipped with hard-disk storage to record one MPEG-2 stream onto the hard drive while decoding and displaying a second.