Configurable Controller for High-Resolution LED Display Systems

Abstract

Light-emitting diode (LED) display systems are implemented in various resolutions and aspect ratios to satisfy various display requirements. The requisite resolution and aspect ratio can be obtained by combining the appropriate LED panels. However, using different types of LED panels require using different types of LED controllers to drive them, which constitutes a rather burdensome design constraint. In addition, a driving circuit inside an LED panel may be modified to improve the display quality by adopting a new driving scheme or new LED elements. Furthermore, it may sometimes be necessary to create a completely new LED panel. All of these situations require the design of new LED controllers. In this paper, we, therefore, propose a configurable LED controller that can be used with various types of LED panels without requiring hardware modification or redesign. The proposed LED controller consists of an application-specific instruction-set processor (ASIP) and custom hardware. The ASIP is software programmable, and the custom hardware is employed to obtain a high operating speed. Moreover, the function of the custom hardware can be configured through the ASIP software program for generating the necessary address sequence to read the image bit plane memory and, consequently, to accommodate the target LED panel. Therefore, the proposed LED controller provides the advantages of flexibility and high-speed operation. The proposed LED controller was implemented using Xilinx Virtex-5, and it successfully drove LED panels having 64 x 96, 96 x 80, and 128 x 64 pixels at refresh rates of 3125, 2232, and 1736 Hz, respectively. An analysis of the operational capability indicates that, at the same refresh rate, the field-programmable gate array prototype of the proposed controller drives 1.44 times more pixels per unit time than a state-of-the-art commercial controller.