Learn More
—Backlight systems dominate the power requirements of battery-operated hand-held devices with color thin-film transistor (TFT), liquid crystal displays (LCDs). We introduce dynamic luminance scaling of the backlight with appropriate image compensation. Dynamic backlight luminance scaling (DLS) keeps the perceived intensity or contrast of the image as close(More)
An LCD (Liquid Crystal Display) is a standard display device for hand-held embedded systems. Today, color TFT (Thin-Film Transistor) LCDs are common even in cost-effective equipments. An LCD display system is composed of an LCD panel, a frame buffer memory, an LCD and frame buffer controller, and a backlight inverter and lamp. All of them are heavy power(More)
The MPEG-21 Multimedia Framework initiative aims to support a wide range of networks and devices in the delivery and consumption of multimedia resources. One of the primary goals of MPEG-21 is universal multimedia access (UMA) through Digital Item Adaptation (DIA), which supports multimedia streaming to heterogeneous terminal devices ensuring the same(More)
COLOR THIN-FILM TRANSISTOR (TFT) liquid-crystal display (LCD) panels enable battery-operated, hand-held embedded systems to support full-featured multimedia, and have replaced monochrome super-twisted nematic LCD panels in most applications. Most importantly, a TFT LCD panel does not illuminate itself, but filters a backlight source, and this backlight is a(More)
In this paper, we introduce a precise energy characterization of SDRAM main memory systems and explore the amount of energy associated with design parameters, leading to energy reduction techniques that we are able to recommend for practical use.We build an in-house energy simulator for SDRAM main memory systems based on cycle-accurate energy measurement(More)
Despite the limited power available in a battery-operated hand-held device, a display system must still have an enough resolution and sufficient color depth to deliver the necessary information. We introduce some methodologies for frame buffer compression that efficiently reduce the power consumption of display systems and thus distinctly extend battery(More)
ALONG WITH SPEED AND COST, energy consumption is now a primary performance metric for battery-operated embedded systems. A well-designed embedded system should be globally optimized to the target application , from the user interface to the device technology. This type of global optimization over many layers of software and hardware is challenging because(More)
Memory systems are dominant energy consumers, and thus many energy reduction techniques for memory buses and devices have been proposed. For practical energy reduction practices, we have to take into account the interaction between a processor and cache memories together with application programs. Furthermore, energy characterization of memory systems must(More)
Designing cost-sensitive embedded products such as cellular phones and portable media players requires maximizing a platform's performance while minimizing energy use. For example, if two software implementations of an MPEG-4 decoder perform quite differently on the same target platform , clearly the more efficient version will result in a more(More)
Modern hand-held multimedia terminals consume significant power for their quality display devices. Due to 60Hz or higher LCD refresh operations, frame buffer memory and related buses become dominant power consumers. In this paper, we introduce an efficient frame buffer compression scheme that uses differential Huffman coding and its hardware implementation.(More)