Software Design For Liquid Crystal Display Based On NT68521 Scaler

Nowadays, the liquid crystal display (LCD) is superceding CRT display and becoming the mainstream for its features of smaller volume, lighter weight, lower consumption, flicker-free, etc. In the mean time, researches in our country on this new technology started relatively late, and thus are dropped behind those in European, American and some Asian countries. So it is realistically meaningful to develop system software for LCD and investigate technologies related to it.The research in this thesis originated from a project developing 15-inch LCD display. The project adopts microprocessor NT68F633 and imaging processor NT68521 from Novatek Corporation as its kernel hardware system. Based on the hardware, LCD software system, which was used to realize normal video images as well as OSD menus, was designed according to the requirement from LCD's specification.Through the process of hardware analysis, software design, and system test, this paper, based on the theory of LCD, finally realized a software system for LCD withNT68521 Sealer.At the beginning of the paper, an introduction is given to the physical properties of liquid crystal, working theory of LCD and its driver principle. Then on the basis of hardware containing microprocessor and imaging processor, a thorough analysis is presented to the functionality of video input module, keyboard input module and MCU controlling module. At the same time the data transportation between modules and the processing procedure of imaging signals are also analyzed. The software functions dealing with IIC bus, keyboard, mode detection, OSD menu and factory mode were implemented mostly by C language and partly if necessary by assembly language.At the phase of system test, the video image generator is used for examining all related designed functions. Hereby, a software system for LCD with NT68521 is achieved by the validity and correctness of the design for every part, which are verified via the passing of strict system test.