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SoC for STBs has triple processors

Apr 16, 2008 — by Jonathan Angel — from the LinuxDevices Archive — 111 views

Sigma Designs has introduced a pair of set-top box SoCs that run Linux. Powered by three MIPS cores apiece, the SMP8654 and SMP8655 boast accelerated graphics and compliance with HDMI (high-defintion multimedia interface) 1.3, says Sigma.

The SMP8654 and SMP8655, differing only in the latter's omission of Macrovision, are designed to replace the company's “industry leading” SMP8634. And indeed, they appear to be a significant advance on it. Where the older SMP8634 had a 300MHz MIPS CPU and a 200MHz security CPU, the SMP865x chips boast triple MIPS processors, for a claimed fifty percent speed boost, according to Sigma claims:

  • A 500MHz processor runs the operating system and applications
  • A 333MHz processor manages interrupts and part of the network stack
  • A 333MHz security CPU, deliberately inaccessible by external interfaces, manages authentication, key generation, and content access functions

Sigma's 865x SoC sports three processors
(Click to enlarge)

The SMP865x chips offer high definition video decoding, including H.264 (MPEG-4 part 10), WMV, VC-1, MPEG-2, and MPEG-4 (part 2). They also support China's home-market AVS (audio video standard). HDMI 1.3 support offers bandwidth to 340MHz, while adding support for the Dolby TrueHD and DTS-HD formats used by Blu-Ray and HD-DVD.

Other touted features for the SMP865x chips include:

  • On-chip flash memory (24K for 500MHz processor, 4K for interrupt/stack processor)
  • DRM (digital rights management) engines
  • 2D graphics processor including scaling, JPEG and OpenType acceleration
  • Dual gigabit Ethernet controllers
  • Dual USB 2.0 controllers
  • DDR2 controller supporting memory up to 666Mbps
  • NAND flash controller
  • SATA controller
  • Audio I/O
  • Simultaneous HD and SD video outputs

Sigma did not cite pin compatibility with its previous SoCs, but said the SMP865x chips are software-compatible with them.

In addition to supporting Linux, the SoC supports Windows CE and Microsoft's Mediaroom IPTV software stack (right), renamed from IPTV Edition last July. Mediaroom is a Windows CE-based technology that is licensed directly to broadband service providers. Features include simultaneous recording of multiple HD and SD programs, media sharing, and a MultiView feature that lets one screen show up to six channels simultaneously.

IPTV has been expanding rapidly, with more than 10 million subscribers in Europe, North America, and Asia, according to figures cited by Sigma. The company says it ships chipsets to “nearly all” of the top STB manufacturers, and 24 of the top teleco operators. Deployments are split between Mediaroom and various flavors of Linux.

Further information

Sigma's 865x series is sampling now, the company says. Product demonstrations are being provided at this week's National Association of Broadcasters (NAB) show in Las Vegas.

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