Silicon Motion's SM768 USB display /docking station SoC enables multiple display at 4K ultra high definition through USB interface. Target applications include USB display docking station adapters used in shared office space, conference room, classroom, or hotel.

With Silicon Motion's proprietary technology, InstantView®, users of a docking station can instantly mirror their computer screen to any external display, with no need to install a display driver. Docking stations based on the SM768 solution combine high graphics performance with low CPU loading and low power consumption. The CAT™ (Content Adaptive Technology) compression technology implemented by Silicon Motion offers a high compression ratio while imposing a low processing overhead on the host computer's CPU. 

The Silicon Motion solution for USB docking stations based on the SM768 is available. SMI also provides reference design as the basis for an end product design helps docking station manufacturers to reduce development time and shorten time-to-market for new product designs. It is compatible with all current versions of the Microsoft Windows, Apple macOS, Linux operating systems, Android, and ChromeOS.


  • CPU: ARM Cortex R5 Processor 
  • GPU: 128-bit 2D Graphics engine supports HW cursor, video overlay, and alpha blending
  • System interface: USB 3.0 Device or PCI-E Gen2 x1/x2 lanes
  • 2x independent display channels in a single chip
  • CAT (Content Adaptive Technology) to accelerate USB display by adaptive compression algorithms
  • Display Resolution up to
    ・4K (3840x2160)@30Hz
    ・HD(1920x1080) & 2K @60Hz
  • Display Modes: Extended Desktop Single & Dual View, Clone, Portrait/Landscape modes
  • Embedded 1x HDMI v1.4 transmitter supporting HDCP
  • Dual CRT 350MHz DAC RGB outputs
  • Dual-channel LVDS
  • Dual digital 24-bit RGB/TTL video output 
  • Hardware Accelerated Video Decoder: H.264, MPEG 2/4, MJPEG, etc.
  • Option to embed 256MB DDR3 in a single package (MCM). Support external DDR up to 1GB
  • Integrated 4-port USB 2.0 Host and Hub for peripherals: Keyboard/Mouse/Network/Storage
  • I2S for Audio support
  • Dual I2C and SPI
  • Two ZV ports to capture incoming video from cameras or other devices
  • Software Support
    ・Windows 7/8/10 & Servers, 32-bit, and 64-bit
    ・macOS X
    ・Linux OS(Ubuntu, RedHat, SUSE, etc)


CAT™ (Content Adaptive Technology)

Silicon Motion's CAT™(Content Adaptive Technology) uses multiple image/video processing algorithms to compress display data and minimize bandwidth usage. At the same time, CAT uses minimal host CPU usage to achieve low latency and high-quality displays.

CAT processes desktop contents adaptively
  • Graphics/3D Image will be processed by high compression ratio MJPEG codec.

  • Text will be compressed by lossless proprietary protocol.

  • Video will be transferred in original compressed formats and decode in SoC's HW accelerated decoder

By offloading much of the compression work to a hardware accelerator, the CAT technology both runs faster and imposes less loading on the CPU. As will be shown later, this helps the SM768 to achieve very low CPU loading.

Low Latency
  • SM768 display process pipeline (compression & decompression) is optimized to reduce latency
  • Display latency for a full HD frame is < 16ms
  • Lab test picture below showed a measurement similar to Wireless Miracast. The left monitor is natively display, and the right monitor is SMI Display SOC. Both monitors are cloned to display the same video clip which has a frame counting number that increases 60 times per second
  • The result shows both monitors are showing the same frame at any time, which means the latency is minimal and the difference is not distinguishable to human eyes

Comprehensive system solution for USB-to-display bridging

Compared to competing devices, then, SMI Graphics SoC offers much lower host CPU loading for an unimpaired user experience. This is backed by the excellent picture quality provided by the CAT compression feature, low latency in dual-display mode, low power consumption, and compact dimensions. The architecture was chosen by Silicon Motion also enables OEMs to implement a complete docking station and other product designs with few external components.

The USB and CAT software as well as a real-time operating system run inside the SM768. This explains how it is able to support the latest docking station and dongle designs which are helping to bring greater flexibility, convenience, and portability to many types of computing equipment in the home, office, store, and factory. It is also worth noting that the same SM768 device also features a PCI-e interface for use with other types of hosts, enabling OEMs to develop designs both for the USB market and for other applications.


Enabling USB docking station to plugin-and display

Silicon Motion has developed a new InstantView software application that seamlessly configures the host content for viewing on any display, with no need for a display driver.

The InstantView software is an application that runs on the host computer. It automatically starts up on the host computer when a USB connection is made to a docking station. As soon as a computer with the InstantView app is connected to a docking station, a welcome message appears on the computer screen. This enables the user to instantly mirror the computer screen to a single or dual display outputs linked to the docking station, by clicking the "Connect" button. The effect for the user is of  "plug-and-play" display functionality: there is no delay, and no need for driver installation or other software operation.

The InstantView software supports instant screen mirroring to display. The software also supports an "Extended Display" option. The operation of this Extended Display option involves the silent installation by the InstantView software of the relevant display driver, after which enhanced dual-display functions are available to the user. Whether the user chooses the mirroring or extended display option, the entire display operation is controlled via the intuitive and user-friendly InstantView user interface. This eliminates the need for any intervention by IT support staff.

Selection Guide

File Product Host Bus Graphic Engine Resolution Embedded Memory External Memory
SM768 USB 3.0 PCIe 2.0 x1 or x2 2D 3840 x 2160 (max) 256MB (option) 1 GB DDR2/3 (max)