TFT-LCD driver IC test platform design and implementation

1 Introduction

In recent years, with mobile phones and MP4 video player, and other products, such as number of rapid growth, it is estimated that this year's mobile phone production would reach 10 million units, competition tends to be heated.

For screen display, consumers also put forward higher requirements. Display a large part depends on the driver's mass. Display driver IC has become a struggle for many manufacturers. Currently there are over 20 design company engaged in the small screen display driver IC design. In each of the IC production before after repeated debugging to ensure that the settings meet the design requirements, and achieve better display effect. Design of high speed, ease of debugging, and appearance of the test platform to facilitate debugging out better results and reduce debugging time, and can give customers a fresh feeling, to improve the competitiveness of the product. This paper is targeted at Focaltech-systems Corporation TFT_LCD driver IC design test platform FT1505. Use of C8051F130 is a new company by Cygnal launched the high-performance MCU with high speed, the pipeline structure 8051-compatible CIP-51 kernel, the most rapid up executed instruction 100 MIPS, comparison with 8051 series has increased by a lot of resources, in his chip integrates a single-chip data sampling or control systems almost all analog and digital peripherals, and other features. Comply with the requirements of the platform. In 2007 Shenzhen CHINA IC, illustrates this platform driven modules, attracted many customers and visitors of the eyeball, achieve very good results.

2 system hardware circuit design

System hardware circuit includes a variety of power supply/booster circuit, MCU, movie, FLASH, driver download, hi-speed USB peripheral circuit and at the interface between the circuit.

The entire system architecture in Figure 1.

(1) power/step-up circuits

Power circuit provided mainly by APW7080 APL1117 provide 5V and 3 .3V.

Boost circuit primarily by DS9197. Adjustable rheostat gives 1.5 ~ 4.5V voltage.

(2) MCU peripheral circuits and other parts of the interface circuit (Figure 2)

MCU P0 received FLASH 8-bit data bus, P1, P2, P3-FLASH, driver of the address bus.

P6 port pick up FLASH and driver control signal lines. Flash_nce flash_noe flash_nwe, respectively, is the Flash movie selected, write, and read control signal, high level valid. TFT_IM3 ~ TFT_IMO is driven IC choosing read data interface. When the selected 1100 is an 8-bit interface, selected when a 16-bit 1101 interface. TFT_ncs, TFT_RS, TFT_nwr, TFT_RD, TFT_nRST are driven IC chip selected, select the register, writing and reading and hardware reset control signal cable, control driver timing. MCU through TMS, TCK, TDI, TDO four pins and hi-speed USB port connected, you can download from the download pictures and other system data into Flash.

(3) FLASH driver IC peripheral circuits, and interface circuits (Figure 3, Figure 4)

Addr0 ~ Addr20 is pooled to display data, address bus, DATA0 ~ DATA7 is FLASH storage data of the address bus.

RS, CS, RD, WR, RST is timing control line, via software control to achieve from FLASH and remove the single-chip memory data, the data delivered to the IC, IC interface work properly.

3 system software design

(1) initialization and timing control

The hardware system power-on reset, the MCU through software based, Flash, driver IC and display properties to initialize.

Including the definition of each interface pin set, set the register values determine the driver's working conditions, work patterns, etc. The display of pictures and other data via high-speed USB download to on-chip RAM and outside the Flash movie. After that, according to the driver's timing to display module to display the data. Driver IC read/write control timing indicated by Figure 5. IC's timing control signals have RS, CS RD, WR, four. They are the registers enable signals, signals, writing tablets selected enable signal and read the signal. In addition to the line of control by RST hardware reset.

(2) write program

Including write MCU on-chip RAM and write outside the Flash movie.

Smaller amount of data can be directly written to the on-chip RAM, the advantages of chip RAM is the data transfer speed, online debugging, the disadvantage is that saving smaller capacity. C8051F130 chip RAM 128 kBytes. Storing large volumes of images is required outside the Flash movie. Piece of Flash transmission is slow, savings capacity is large, use AM29LV160 memory size is 2 Mbytes. Its storage space distribution in table 1. Take a picture of 320 * 240, bmp format files into a 16-bit true color in HEX file size is 150 kBytes. A Flash in the can accommodate 10 picture of the amount of data. C8051F130 each can handle 64 Kbytes of data. To facilitate the calculation of addresses, each picture is divided into 5 sections, the first 4 segment size is 32Kbytes, last segment size is 22Kbytes. Download a FlashAll data points in 10 * 5 times in the download.

From the table and see SA0 ~ SA3 size and SA4 ~ SA34, write data to pay particular attention to the address allocation.

(3) reading program

From external FLASH RAM or tablets.

The driver IC and FLASH are direct read mode, the data in a FLASH by sequential control directly through Addr0 ~ Addr17 sent to the IC.

4 closing

This article on LCD design a debugging environment based on the test platform of TFT_LCD C8051F130, Panorama map shown in Figure 6 and Figure 7, FLASH on the back of the PCB.

Through several tests and trial, proved to be a high speed, stability, ease of debugging platform. On similar COG debugging and testing system.