So far, mobile consumers seem to be easily drawn to the ability to play games, view videos, or exchange pictures. This trend is turning the display from a component into a winning feature of the device. To make sure that future displays don't disappoint users, Epson Corp. (www.epson.com) and Tokyo-based Renesas Tech-nology Corp. (www.renesas.com) have partnered. They're going to jointly develop open-standard specifications for a high-speed interface.
As Epson and Renesas Technology observed, manufacturers face several challenges when they support features like multi-megapixel cameras and high-resolution liquid-crystal displays (LCDs). First, they need to reduce the number of interface lines. In addition, the demand for sophisticated functions creates a need for high-speed data transmission and electromagnetic-interference countermeasures. To conquer these problems, the companies' specifications envision the use of Epson's Mobile Graphics Engine—a display control LSI—with Renesas Technology's SH-Mobile multimedia-application processor as host. This system will employ LCD drivers from both companies (see figure).
The companies dubbed this interface the "Mobile Video Interface," or MoVI. Their specifications are being tailored specifically for the high-speed transmission of display images. As a result, circuit composition should be able to be simplified and further miniaturized. In addition, MoVI will support full duplex transmission. High-speed, two-way transmissions will be permitted between devices. The maximum data transfer rate will be 200 Mbps/channel in both directions.
Between the devices, the interface standard also will establish a fixed host-target relationship. The MoVI circuit on the target side will receive a clock signal from the host side. No phase-locked loop (PLL) will be required to synchronize output signals and frequencies with input signals and base frequencies. Power requirements will therefore be reduced.
Finally, Epson and Renesas Technology plan to make the high-speed specifications available openly and on a license-free basis. They'll be available to mobile application developers, mobile-device manufacturers, and other industry participants. The companies are working to establish standard MoVI-based specifications for a wide range of products. Their target date is the first quarter of 2004.