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Graphic LCD panel - Introduction

Graphic LCD panels use a digital interface and are easy to interface to FPGAs.

The different interfaces

Graphic LCD panels come in 2 flavors:
  1. With a Video-like interface
  2. With a CPU-peripheral-like interface
1. Video-like interface
2. CPU-peripheral-like interface
  • Low cost & widely available (used in notebook computers for example)
  • Easy to control from an FPGA
  • Freedom on what is displayed (frame-buffer/on-the-fly video/sprites/hardware mouse cursor ... or any combination of these)
  • Easy to attach to microcontrollers
  • A frame-buffer memory is integrated to the panel
  • Requires a video controller (FPGA or dedicated chip)
  • Requires some external memory (for the frame-buffer, character generator, ...)
  • Higher cost & lower availability
  • For frame-buffer applications only
How it works
  • Uses a video signal - with HSync (horizontal sync) and VSync (vertical sync) pulses
  • Similar to a VGA signal, but with digital video signals
  • The panel appears like a memory (SRAM) to the microcontroller
  • The CPU writes to the SRAM and the data appears on the screen

This project uses "type-1" panels - since we use FPGAs here, that's the most appropriate.