26萬色vgatft液晶單芯片低功耗驅(qū)動集成電路

1、附錄ALow Power 260k Color VGA TFT LCD One-chipDriver ICAbstract - In this study, we present a 260k Color VGA TFT one-chip LCD Driver IC that consumes low power in module.To reduce power consumption and a chip size, we used a sub-pixel rendering and a data compression algorithm.The currently, in order

2、to display the bigger and higher resolution, the imbedded graphic SRAM size becomes bigger.But, because the mass-production size has limitation, the driver IC of a VGA resolution is normally two or three chip solution.The study is the first time made VGA one-chip IC in world. The IC is implemented i

3、n a 0.15um process.I. INTRODUCTIONCurrent telecommunication technology has improved amazingly.These improvements have revitalized hand-held modules and increased multi-media services.To use a hand- held module for a longer time, each chip needs to become smaller and consume less power.The size of di

4、splay equipment has become bigger and the resolution higher. Due to this, power consumption of display equipment has also become higher. Power reduction for display equipment has become a very important issue.The multi-color display panel is implemented by arranging an RGB (red, green, blue) color f

5、ilter.The color rectangular panel is supplied by row-direct voltage and column-direct voltage. The difference of the two direct voltages is the driving voltage of the pixels. This method is called multiplex addressing. The LCD driver IC generates and supplies the voltage level.This paper presents a

6、260 k-color TFT LCD one-chip driver module that consists of a gate driver and source driver. The gate driver generates the driving voltage of column direction and common voltage. The gate driving voltage is of two types: a selected level and a non-selected level. The level of these voltages is deter

7、mined by the characteristics of each panel. When one gate line is selected, the source IC drives data voltage levels that are valued by decoding stored data. The different voltage of the gate's selected level and source's data level determine the display material arrangement.With a higher co

8、lor resolution, the embedded memory capacity needs to be bigger in the LCD driver IC. The power consumption of the merged memory also becomes a very important issue. With a higher resolution and bigger panel，a bigger embedded memory size is necessary. Because of this, shrinking the RAM size is a dom

9、inant factor in the chip size of a driver IC.In this paper, section II presents the architecture of graphic driving IC. Section III discusses the algorithm of sub-pixel rendering. Section IV discusses the image data compression. Section V, the implemented sample is compared in VGA driver IC. The chi

10、p samples are implemented in a 0.15 um process and tested in manual test board and probing machine (T6371 Advantest).II. STRUCTURE OF THE DRIVER ICGenerally, the driver IC is composed of a logic part, an analog part, and a memory part. The analog part is composed of the LCD driver, DCDC converter, v

11、oltage divider, and oscillator. The oscillator circuit generates a clock for display. The DCDC converter circuit receives the generated clock and generates the highest/lowest voltage level. The voltage divider circuit divides between the highest and lowest level. The driver block supplies the variou

12、s voltages to the panel.The 260k TFT one-chip IC is composed of a logic, a embedded memory, an oscillator, a DCDC converter block, a source/gate driver block and a common voltage generating block. The logic part is composed of an MPU interface block, memory-addressing block, and timing control block

13、. The MPU interface block interfaces between the driver IC and the external MPU.The memory-addressing block receives the decoded signal in the MPU interface and generates the memory address.The resister array is included in the gray scale generator.The implemented driving IC has three types of adjus

14、tment: a gradient adjustment, an amplitude adjustment, and a fine adjustment. The timing control block generates a signal, which controls the display panel.The embedded memory is the same as normal memory. The output data from memory is transferred to the source driver. The driver has the sub-pixel

15、rendering and compressing process in order to decrease the embedded memory size. A data form external chip is received by the system interface block, the internal format converted data of a processed in system interface is sent to GMA block (Input gamma block), the pre-SPR formatted data is sent to

16、SPR (Sub-Pixel Rendering) block. The SPR block calculates the one pixel with around pixel data and then output processed a sub-pixel data. Because the sub-pixel data has the around pixel information, the stored data can be lower data quantity.The sub-pixel is sent to compressing block and the compre

17、ssed output is stored in the embedded memory.The stored data is decompressed and output to the source driver in the display clock. The display data in the source driver block is not same with normal RGB strips type. The data type is called the Pentile Matrix type. The Pentile Matrix type can be had

18、original visibility in a human eye.The sub-pixel rendering and the compression processing can be had lower memory size and low power consumption than the normal processing.III. SUB-PIXEL RENDERINGThe sub-pixel rendering algorithm in out chip is used a Clair Voyante's algorithm 3, 4. The present

19、application relates to the conversion of graphics data formats from one form to another, and specifically to the conversion of (red-green-blue) RGB graphics to improved color pixel arrangements used in displays.The present state of the art of color single plane imaging matrix, for flat panel display

20、s, use the RGB color triad or a single color in a vertical stripe as shown in prior art Figure. 1. The system takes advantage of the Von Bezold color blending effect by separating the three colors and placing equal spatial frequency weight on each color. However, these panels are a poor match to hum

21、an vision.Graphic rendering techniques have been developed to improve the image quality of prior art panels.Benzchawel,etal.in3 teaches how to reduce an image of a larger size down to a smaller panel. In so doing, Benzchawel, et al. teach how to improve the image quality using a technique now known

22、in the art as "sub-pixel rendering". More recently Hill, etal. in 4 teach how to improve text quality by reducing a virtual image of text, one character at a time, using the very same sub-pixel rendering technique.The above prior art pay inadequate attention to how human vision operates. T

23、he prior art's reconstruction of the image by the display device is poorly matched to human vision. The dominant model used in sampling, or generating,and then storing the image for these displays is the RGB pixel ( or three-color pixel element), in which the red, green,and blue values are on an

24、 orthogonal equal spatial resolution grid and are co-incident. One of the consequences of using this image format is that it is a poor match both to the real image reconstruction panel,with its spaced apart, non-coincident, color emitters, and the human vision.This effectively results in redundant,

25、or wasted, information in the image.Full color perception is produced in the eye by three-color receptor nerve cell types called cones. The three types are sensitive to different wave lengths of light: long, medium, and short ("red", "green", and "blue", respectively).

26、The relative density of the three wavelengths differs significantly form one another. There are slightly more red receptors than green receptors. There are very few blue receptors compared to red or green receptors. In addition to the color receptors, there are relative wavelength insensitive recept

27、ors called rods that contribute to monochrome night vision.The human vision system processes the information detected by the eye in several perceptual channels: luminance, chrominance, and motion. Motion is only important for flicker threshold to the imaging system designer. The luminance channel ta

28、kes the input from only the red and green receptors. It is "color blind". It processes the information in such a manner that the contrast of edges is enhanced. The chrominance channel does not have edge contrast enhancement. Since the luminance channel uses and enhances every red and green

29、 receptor, the resolution of the luminance channel is several times higher than the chrominance channel. The blue receptor contribution to luminance perception is negligible. Thus, the error introduced by lowering the blue resolution by one octave will be barely noticeable by the most perceptive vie

30、wer, if at all, as experiments at Xerox and NASA, Ames Research Center (R Martin, J. Gille, J. Larimer, Detectability of Reduced Blue Pixel Count in Projection Displays,SID Digest 1993)had demonstrated.Color perception is influenced by a process called "assimilation" or the Von Bezold colo

31、r blending effect. This is what allows separate color pixels (or sub-pixels or emitters) of a display to be perceived as the mixed color. This blending effect happens over a given angular distance in the field of view.Because of the relatively scarce blue receptors,the blending happens over a greate

32、r angle for blue than for red or green.This distance is approximately 0.25 degree subtends 50 miles(1,270u)on a display.Thus,if the blue sub-pixel pitch is less than half (625u) of this blending pitch,the colors will blend without loss of picture quality.Sub-pixel rendering, in its most simplistic i

33、mplementation, operates by using the sub-pixels as approximately equal brightness pixels perceived by the luminance channel. This allows the sub-pixels to serve as sampled image reconstruction points as opposed to using the combined sub-pixels as part of a ture pixel.By using sub-pixel rendering,the

34、 spatial sampling is increased,reducing the phase error.If the color of the image were to be ignored, then each sub-pixel may serve as a though it were a monochrome pixel,each equal. However, as color is nearly always important (and why else would one use a color display?). then color balance of a g

35、iven image is important at each location.Thus,the sub-pixel rendering algorithm must maintain color balance by ensuring that high spatial frequency information in the luminance component of the image to be rendered does not alias with the color sub-pixels to introduce color errors. The approaches ta

36、ken by Benzchawel, et al. in 3, and Hill, et al. In 4, are similar to a common anti-aliasing technique that applies displaced decimation filters to each separate color component of a higher resolution virtual image. This ensures that the luminance information does not alias within each color channel

37、. Figure 1. RGBW strip detection in eyes附錄B26萬色VGA TFT液晶單芯片低功耗驅(qū)動集成電路摘要-在這項研究中，我們提出了一個26萬色VGA TFT液晶單芯片低功率消耗驅(qū)動集成電路。為了降低能耗和芯片尺寸，我們使用了子像素渲染和數(shù)據(jù)壓縮算法。目前，為了顯示更大的和更高的分辨率，要求嵌入式圖形靜態(tài)隨機(jī)存儲器尺寸變得更大。但是，由于大規(guī)模生產(chǎn)規(guī)模的限制，要實現(xiàn)該驅(qū)動集成電路的VGA分辨率通常是兩個或三個芯片才能解決。這項研究是在世界第一次實現(xiàn)的VGA單芯片集成電路。該集成電路是在0.15um工藝下實現(xiàn)的。一. 導(dǎo)言目前的通信技術(shù)在以驚人的速度提高，這些改

38、進(jìn)促使了手持設(shè)備的產(chǎn)生并增加了多媒體服務(wù)。為了使手持設(shè)備工作更長的時間，每個芯片需要變得更小和能耗更低。顯示設(shè)備的尺寸已經(jīng)越來越大并具有更高的分辨率。由于這些，使得顯示設(shè)備的能耗也變得更高。對顯示設(shè)備的降耗已經(jīng)成為一個非常重要的問題 多彩色顯示面板是通過設(shè)置一個RGB （紅，綠，藍(lán)）彩色濾光片來實現(xiàn)的。彩色矩形面板是通過行和列直接電壓來供電的。差異的兩個直接電壓是像素的驅(qū)動電壓。這種方法被稱為多路處理。LCD驅(qū)動集成電路產(chǎn)生并提供電壓標(biāo)準(zhǔn)。 本文提出了一個由門驅(qū)動器和源驅(qū)動器組成的26萬真彩色液晶單芯片驅(qū)動裝置。門驅(qū)動器產(chǎn)生列方向的驅(qū)動電壓和一個共同的電壓。門驅(qū)動電壓分為兩類：選擇一級和非選擇

39、一級。這些水平的電壓是由每個面板的特點來決定的。當(dāng)一個門線被選中，源集成電路驅(qū)動被解碼存儲的數(shù)據(jù)電壓一級。門的選擇級別和源的數(shù)據(jù)級別不同的電壓確定于材料的實現(xiàn)。要有較高的色彩解析度，在LCD驅(qū)動器集成電路中的嵌入式存儲容量就需要更大。集成內(nèi)存的耗電量也成為一個非常重要的問題。由于較高的分辨率和更大的面板，具有一個更大嵌入式內(nèi)存是必要的。正因為如此，縮小隨機(jī)儲存期的容量是決定驅(qū)動集成電路芯片大小的主要因素。本文第二部分介紹了圖形驅(qū)動集成電路的架構(gòu)。第三節(jié)討論了子像素渲染的算法。第四節(jié)討論了圖像數(shù)據(jù)壓縮。第五節(jié)中，在VGA驅(qū)動集成電路執(zhí)行樣品的比較。該芯片樣品執(zhí)行0.15微米這個工藝并在手工測試板

40、和探測機(jī)（愛德T6371）上經(jīng)過了測試 。二. 驅(qū)動集成電路的結(jié)構(gòu)一般來說，驅(qū)動集成電路由一個邏輯部分，模擬部分，內(nèi)存部分組成。模擬部分由LCD驅(qū)動器，數(shù)碼制作轉(zhuǎn)換器，分壓器和振蕩器組成。振蕩電路產(chǎn)生一個顯示時鐘。數(shù)碼制作轉(zhuǎn)換電路接收時鐘并產(chǎn)生最高/最低電壓標(biāo)準(zhǔn)。分壓器在最高和最低電平間驅(qū)動。驅(qū)動模塊為面板提供不同的電壓。26萬色TFT單芯片集成電路有一個邏輯部分，嵌入式存儲器，一個振蕩器，一個數(shù)碼制作轉(zhuǎn)換塊，源/柵極驅(qū)動塊和一個共同的電壓生成塊組成。邏輯部分由一個微控制器接口模塊，內(nèi)存處理塊，和定時控制模塊組成。該微控制器接口塊連接驅(qū)動器集成電路和外部微控制器。內(nèi)存處理塊接收微控制器接口的解

41、碼信號，并生成內(nèi)存地址。電阻陣列包含于灰階生成器。執(zhí)行驅(qū)動集成電路有三種類型的調(diào)整：梯度調(diào)整，幅度調(diào)整，以及微調(diào)。時間控制模塊生成一個控制顯示面板的信號。嵌入式內(nèi)存跟正常的內(nèi)存一樣。從內(nèi)存輸出的數(shù)據(jù)被轉(zhuǎn)移到源驅(qū)動器。為了便降低嵌入式存儲器的容量，該驅(qū)動器有子像素渲染和壓縮過程。外部芯片傳來的數(shù)據(jù)被系統(tǒng)接口模塊接收，處理系統(tǒng)接口的內(nèi)部格式轉(zhuǎn)換數(shù)據(jù)被發(fā)送到圖形處理器模塊（輸入伽瑪塊），預(yù)子像素格式的數(shù)據(jù)發(fā)送到子像素渲染模塊。子像素渲染模塊計算出一個像素與周圍像素數(shù)據(jù)，然后輸出處理了的子像素數(shù)據(jù)。由于子像素數(shù)據(jù)包含有周圍像素的信息，可以降低存儲數(shù)據(jù)的數(shù)據(jù)量。子像素被發(fā)送到壓縮塊，而壓縮的輸出則是被儲

42、存到嵌入式存儲器中。 在顯示時鐘下，存儲的數(shù)據(jù)被解壓并且輸出到源驅(qū)動器。在原驅(qū)動器模塊中的顯示數(shù)據(jù)跟平常的RGB帶類型不一樣，其數(shù)據(jù)類型被稱為Pentile矩陣式。Pentile矩陣含有人眼能見的原始能見度。子像素渲染和壓縮處理可以比正常的處理減少內(nèi)存容量的消耗和降低耗電量。三. 子像素渲染外部芯片中的子像素渲染算法是采用了克萊爾Clair Voyante的算法 3 和 4 。當(dāng)前的應(yīng)用涉及到轉(zhuǎn)換的圖形數(shù)據(jù)格式從一個到另一個形式，特別是從（紅綠藍(lán)） RGB圖形到用于顯示的改善彩色像素陣列的轉(zhuǎn)換。用于平板顯示器的色彩單一平面成像矩陣技術(shù)的現(xiàn)狀，就是使用RGB色彩三合會或在垂直條紋的單一顏色如圖1

43、所示。該系統(tǒng)通過分離三種顏色和為每種顏色設(shè)置相同的空間頻率比重，充分利用了Von Bezold的顏色混合效應(yīng)。但是，這些面板對人眼來說就很無味了。圖形渲染技術(shù)在朝著改善預(yù)先藝術(shù)面板的圖像質(zhì)量方向發(fā)展。Benzchawel等在多彩圖像的顯示方法和儀器教導(dǎo)如何減少較大規(guī)模的圖片下降到一個較小的面板。在這樣做時，Benzchawel 等傳授了怎樣使用目前已知的“子像素渲染”來提高圖像質(zhì)量。最近，Hill等在文本圖像的顯示方法和儀器中，教授了怎樣通過使用非常相近的子圖像渲染技術(shù)來減少文本或字符的虛擬圖象，以提高文本質(zhì)量。上述預(yù)先技術(shù)對人類視覺如何運作重視程度不夠。通過顯示設(shè)備對圖像的預(yù)先技術(shù)的重構(gòu)很難

44、達(dá)到人們視覺的要求。主導(dǎo)的模型在取樣或產(chǎn)生中使用，然后為顯示設(shè)備儲存的這些圖像是RGB像素（或三種顏色的像素組成部分），其中紅，綠，藍(lán)值均在一正交平等的空間分辨率網(wǎng)格中并且有相關(guān)性。使用此圖像格式的一個后果是，導(dǎo)致圖像貧乏同時在間距，非同步，彩色排放，人的視覺等方面與實際圖像重建面板匹配差。這實際上導(dǎo)致對圖像信息的多余或浪費。全彩色的感知是眼睛神經(jīng)細(xì)胞類型稱為錐三色受體產(chǎn)生的。這三色受體對不同波長的光很敏感：長波、中波和短波（ 分別對應(yīng)“紅色”、“綠色”和“藍(lán)色”）。 三個波長的相對密度彼此不同。紅色受體比綠色受體稍微多一些。相比于紅色或綠色的受體，藍(lán)色受體很少。除了色彩受體外，還有對波長不敏

45、感的稱為棒受體，它有助于黑白夜視。人類視覺系統(tǒng)處理通過眼睛的一些知覺頻道獲得的信息如：亮度，色度，和移動。移動是對圖像像系統(tǒng)設(shè)計的閃爍閾值唯一重要的，亮度通道需要的輸入只需來自紅色和藍(lán)色受體。它本身則是“色盲”。它對信息是以增強邊緣的對比這種方式來處理的。色度通道沒有邊緣增強。由于亮度通道的使用和增強每個紅色和綠色受體，該決議的亮度渠道是高出幾倍的色度通道。該亮度渠道的圖形分辨率比色度通道要高好幾倍。藍(lán)受體為亮度知覺的貢獻(xiàn)是微不足道的。因此，降低藍(lán)色分辨率一個程度將使感知器幾乎注意不到的言論是錯誤的，在這個層次上，作為施樂和美國航天局的專家們，艾姆斯研究中心（學(xué)者M(jìn)artin，學(xué)者Gille ，學(xué)者Larimer ，探測還原藍(lán)像素的