Bus Interface For Highresolution Liquid Crystal Screens Part 1

56 EN"vemi391JS INTERFACE FOR HIGH- RESOLUTION LIQUID CRYSTAL SCREENS Part 1 Although large LC display modules are currently available in many shapes and sizes, their special serial input calls for the use of an interface to enable connection to a computer bus. The interface described here is versatile, yet relatively simple to configure and program as a bus-connected device in a number of popular computer systems. Although the application discussed concentrates mainly on the 400x64 dot matrix LCD module Type LM40001 from Sharp, the interface board is also suitable for a number of similar units in Hitachi"s LM series. Liquid crystal display (LCD) units for text and graphics applications are usually supplied as a module consisting of a glass-protected, reflective backplane (the actual display), and a controller board attached to it at the rear side. The controller translates the data applied to its serial input into backplane waveforms, which result in dot patterns that form legibl...