New chip powers tiny Linux set-top box

Chipmaker Zarlink Semiconductor has launched a new family of digital television processors that it says will mean smaller, less expensive, more sophisticated hardware for receiving terrestrial digital television signals.

Boxes using the new chips can run on Linux, are appropriate for interactive digital television services, and use little power, Zarlink said.

The ZL10310 and ZL10311 chips are designed for use with the terrestrial digital video broadcast (DVB-T) standard created by the European Telecommunications Standards Institute (ETSI), which is used by the Freeview service in the UK. The standard is also being rolled out in European countries such as Spain, France, Germany and in Singapore and Australia.

In Britain, the government is keen to switch off analogue terrestrial transmissions by 2010, but has said it will not take the step until nearly all televisions are digitally enabled. The recently launched Freeview free-to-air service is considered key to this project, but the wide availability of inexpensive decoders is another necessary part of the puzzle.

Current Freeview-style set-top boxes have already dispensed with the V0CR-type form factor in favour of an alarm clock-sized box that manufacturers prefer to call a digital television adapter. Using Zarlink's reference designs, manufacturers could build an adapter about the size of a wallet, with a SCART connection to the television. Another, even smaller design will plug directly into the television's SCART port and has a dongle for receiving infrared remote control signals.

"There is more demand now for the smaller form factor set-top boxes," Paul Fellows, DTV product line director, said. "For Freeview, people are looking for an unobtrusive solution. The traditional video recorder size is losing favour."

Zarlink said that its current smallest reference design allows a box to be built for less than £40, and this will drop to around £30 with future designs. The retail price will depend on how the box is sold and distributed, according to Zarlink. The current reference design measures 90mm by 55mm by 25mm.

The chips both incorporate a PowerPC 405TM RISC core and include all major DVB-T functions except for the radio tuner, which is on a separate chip. The ZL10311 adds Dolby digital audio decoding and Macrovision copy-protection capabilities.

Because the PowerPC chip includes memory management systems, it is able to run the Linux operating system, which is used by many high-end set-top boxes, such as the TiVO digital video recorder. This means that manufacturers have the option of running Linux on everything from a basic digital TV decoder right up to a fully interactive device.

The core also supports other popular embedded operating systems such as the offerings of Vxworks and Wind River Systems, Zarlink said.

"Even the smallest module based on these chips runs on the Linux OS," said Fellows. "We have not gone the Linux route just because it's good. It's because our customers have said that's what they want."

The ZL10310 costs $35 (about £22) and the ZL10311 costs $38 (about £24), both in quantities of 1,000. The chips are shipping in volume now, Zarlink said.

Matthew Broersma writes for ZDNet UK