Renesas H8SX user manual Introduction, Direct Drive LCD Overview, Philosophy, Capabilities

Direct Drive LCD Design Guide

1.Introduction

This document provides technical information of how to configure the LCD panel parameters required by Renesas LCD Direct Driver according to the LCD panel datasheet published by the manufacturers. This document will also describe all the APIs (Application Programming Interface) in the LCD Direct Driver and their usages.

An overview of the system hardware is also provided

1.1 Direct Drive LCD Overview

The H8S and H8SX device families include several peripherals that enable the direct connection of RGB interface TFT panels directly to the MCU data bus. These peripherals include the ExDMA (external DMA controller unit) and the TPU (Timer Pulse Unit). With these peripherals and an external RAM device (for LCD frame buffer use), the LCD panel can be refreshed using less than 5% of the MCU processing capacity.

1.1.1Philosophy

The Direct Drive LCD solution was developed to provide a low cost, long life solution for driving TFT panels for use in GUI applications with limited animation requirements. This solution reduces the risk for products with relatively long life on volatile components (such as stand alone LCD controllers, TFT panels with integrated LCD controllers, or application specific microprocessors).

1.1.2Capabilities

The current features of the Direct Drive LCD solution are:

•Ability to use standard PSRAM, SRAM or SDRAM as frame buffer.

•Ability to create multiple frame buffers within the available RAM.

•Ability to dynamically modify frame rate to accommodate varying system update requirements.

•Ability to drive RGB panels at 16bpp up to WVGA resolution at up to 60Hz frame rates.

•Ability to pan larger display regions within a portion of the LCD panel area.

•Very simple operation model…user code manipulates images in the frame buffer. The frame buffer is transparently transferred to the LCD panel.

The Direct Drive LCD solution is highly configurable, and capable of producing many different timing configurations which drive the input signals of TFT-LCD panels from various panel manufacturers. The signal timing generated from the Direct Drive LCD solution depends on your choice panel resolution, frame buffer memory, and desired panel refresh and animation rates.

Although Renesas provides guidelines and examples for configuring the signal timing, Renesas is not responsible for meeting the AC timing specifications of your specific choice of TFT-LCD panel. Please contact your TFT-LCD panel manufacturer to ensure the Direct Drive LCD solution complies with the panel timing limitations.

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