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Linux-oriented SoCs target multifunction STBs

Nov 2, 2007 — by Eric Brown — from the LinuxDevices Archive — 5 views

Horizon Semiconductors has announced a pair of TV decoder SoCs (system-on-chip processors) aimed at multifunction set-top boxes (STBs) driving high-definition screens. The Hz4220 and Hz3220 target cable/IPTV and satellite STBs, respectively, and can run embedded Linux on their built-in application processors, the… company said.

(Click for larger view of Horizon's STB SoC)

The Israeli chipmaker's announcement closely follows one for similar Hz4120 and Hz3120 STB SoCs, which lack some of the IPTV capabilities, but which, unlike the Hz3220/4220, include video transcoding for DVR (digital video recorder) applications. Designed for so-called triple-play (TV, voice, Internet) and quad-play (plus wireless) STBs, both lines of chips offer “real-time, multi-standard, native” decoding at 1080/60p (1920×1080) resolution, says Horizon.

The new Hzx220 SoCs are said to include numerous internal processors, including:

  • Application processor
  • Audio processor
  • 2D/3D graphics accelerator
  • Display and de-interlacer processor
  • Transport processor
  • Security processor

The built-in application processor is capable of running embedded Linux or Windows CE operating systems, said Horizon.

Detailed specs and diagrams for this jack-of-all-trades chip are available only under NDA, but Ofer Austerlitz, Horizon's VP of marketing, offered LinuxDevices a few clues: “Our ICs are based on a unique architecture which uses multiple processors running simultaneously,” said Austerlitz. “Some are RISC-based and others are VLIW, depending on the specific tasks, and these are combined with an MMU-based application CPU enhanced by a dedicated co-processor.”

Aside from the omission of video transcoding for DVR applications on the Hz3220/4220, the main difference between the new STB SoCs and the earlier Hz3120/4120 appears to be the addition of interfaces and security features targeted at the cable and IPTV markets. For example, the Hz4220 supports the cable industry's downloadable conditional access system (DCAS) protocol, enabling DCAS-based leased and retail “digital cable ready” STBs.

Otherwise, the following specifications for the Hz3220/4220 are almost identical to those provided for the previously announced Hz3120/4120:

  • Supports compression standards including: H.264 (AVC) Main and High Profile up to Level 4.2, VC-1 (SMPTE 421M) Advanced Profile @ Level 3, DV, HDV, MPEG-2 at resolutions of up to 1080/60p (1920×1080, 60 frames/sec)
  • Display processor allows multiple plane true color blending, flexible resizing, motion-adaptive high-definition de-interlacing, and motion-compensated picture enhancement
  • 2D and 3D graphics accelerator supports standards including X Window System and OpenGL
  • Multi-channel multi-format audio encoder, decoder, and special audio effects processor supports MPEG-1 Layer I and II, Dolby Digital, Dolby Digital Plus, Dolby TrueHD, MP3, AAC/AAC-LC/AAC-HE, DTS, and WMA
  • I/O includes 10/100/1G Ethernet, USB 2.0, IDE/ATAPI, SMPTE-292, Flash, I2C, SPI/SSI, UART, and others
  • DVI/HDMI output offers HDCP security
  • IEEE 1394


Neither pricing nor final availability information were disclosed. However, development boards are available now, complete with Linux (version not specified), drivers, and an API (application programming interface).

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