The ArcticLink III VX5 offers tablet and smartphone system designers a single solution to solve common design issues like display interface incompatibility, poor viewing experience in sunlight and other difficult environments, and poor battery life that results from bright displays.
While mainly designed for tablets and smartphones, mobile processors are built for a variety of end applications that may include markets like automotive, medical, and industrial. During the processor specification process, architects must choose from a variety of display interfaces. 3 are particularly popular:
Processor architects most often cannot support all three interfaces on their devices, as cost and pinout requirements will restrict the choice to 1 or perhaps 2 interfaces. Once these products are available, OEMs will choose to use them with displays that best fit the OEMs desired product specifications, cost targets, and physical design constraints. For instance, many processors used in tablets feature MIPI, but the displays of choice for >7” tablets are more often than not LVDS, thus forcing the OEM to adopt a MIPI to LVDS bridge. In digital still and DSLR cameras, processors used generally only support RGB, whereas most mass-market displays that fit the form factor of their products are now MIPI. The camera OEM will need to incorporate an RGB to MIPI bridge.
To address these needs, QuickLogic created the VX5 series of ArcticLink III products, featuring display bridge, visual enhancement, and extended battery life. The VX5 offers many alternatives for OEMs in search of a low-cost, multi-function display bridge device.
|VX5AxB||RGB||MIPI||Smartphones, Tablets needing a RGB to MIPI bridge|
|VX5AxD||RGB||LVDS||Tablets needing a RGB to LVDS bridge|
|VX5BxA||MIPI||RGB||Smartphones, Tablets needing a MIPI to RGB bridge|
|VX5BxD||MIPI||LVDS||Tablets needing a MIPI to LVDS bridge|
As the table shows, QuickLogic offers multiple options for bridging RGB and MIPI signals from the processor to MIPI, RGB, or LVDS display panels. The VX5 supports display resolutions up to 1920 x 1080 (WUXGA), including popular resolutions such as 720p (1280 x 720), WXGA (1366 x 768), and 1080p (1920 x 1080). MIPI-DSI is offered in 2 and 4 lane variants with per-lane speeds of 1 Gbps, while LVDS is supported in 1 or 2 channel (4 lanes per channel) architectures.
Displays are the largest single consumer of power in a typical mobile designs. In tablets, large format, high density displays can consume more than 60% of total system power. As the largest consumer of power, displays also represent the largest opportunity for power reduction. While power savings can be had by simply turning down the brightness, doing so reduces the display viewability to a point where most content is un-viewable. There are other ways to reduce brightness (such as Content Adaptive Backlight Control [CABC] or ambient light correction), but these methods are very limited in the maximum power than can be saved; often this is <5% and almost always content-dependent, thus not predictable.
QuickLogic’s VEE and DPO’s approach to display enhancement and power savings is a radical advancement from these legacy technologies.
To best provide display viewability, QuickLogic employs VEE HD+ on the ArcticLink III VX5 devices. VEE HD+ is based on a model of human perception, which is far beyond other, more primitive methods of display enhancement, which are based on machine models of perception. VEE’s human perception model insures that display viewing experience is always most pleasing to the viewer. This stands in contrast to alternative technologies which often sacrifice details in certain areas of the display to increase viewability in other areas, with no concern as to what the content of those particular areas is.
To accomplish this, VEE examines performs a pixel-by-pixel, frame-by-frame analysis of display content, and using the human-eyesight approach, determines the ideal tone curve for each pixel. Rather than legacy global-based improvement technologies, VEE HD+ examines the pixel’s data versus data of neighboring pixels, a smaller area within the entire image, and then the entire image, insuring that local details are always preserved, unlike competing technologies. This insures that the viewer experiences the content in a manner most typical of how the eye would expect to see it, rather than how a machine would best want to interpret the video data.
VEE insures that the display content is viewable in all lighting conditions, including bright sunlight. As many tablet users have experiences, the viewability of the display is greatly diminished when they take their device outdoors during the day. Indoors, the display native ~1000:1 contrast ratio can be enjoyed; however, once outside, the combination of greatly increased ambient light and the light reflection/refraction from the display can reduce that contrast ratio to an effective 20:1, or even lower. To compensate, VEE calculates a unique tone curve for each pixel of every video frame. In essence, VEE is compensating for ambient light conditions through hyper-intelligent modifications to display data, allowing viewability of content and continued viewability of your tablet wherever you might want to.
With VEE (left) and without VEE (right)
With no processing requirements placed on the host system, the VX5’s VEE HD+ technology presents an ideal solution for providing users the best display experience without taxing system resources.
VEE HD+’s sister technology, DPO HD+, works in concert to best conserve power in the system. DPO HD+ receives information on ambient light level through the smartphone/tablet/other device’s on-board ambient light sensor (ALS). Based upon an understanding of the ambient light of the viewer’s environment, DPO HD+ and VEE HD+ work together to provide a unique tone curve for each pixel and lower display brightness without negatively affecting the viewing experience. During the OEM design process, the OEM can choose to implement VEE and DPO based on desires for (1) the best possible viewing experience, (2) the longest-lasting single charge battery life or (3) a determined-mix of power savings and visual enhancement.
DPO HD+ power savings are completely independent of display content, which allows for predictable, consistent savings. OEM-proven systems (see below) using VEE and DPO HD+ have been shown to extend battery life an average of 25%, with OEMs seeing as much as 41% single-charge battery life extensions.
(Actual results depend on implementation)
In addition to DPO HD+, the ArcticLink III VX3 integrates QuickLogic’s Intelligent Brightness Control (IBC) technology, which allows for even greater power savings. When display content is of lower contrast or dynamic range (such as streamed movies from YouTube), display brightness is often needlessly high. When active, IBC examines display data in an effort to further reduce display brightness without affecting the viewing experience. IBC can add up to an additional 10% in system power savings (content-dependent) on top of DPO’s already impressive savings.