液晶显示英文翻译

液晶显示英文翻译 Design of LED Display Control System Based on AT89C52 Single Chip Microcomputer 基于AT89C52单片机的LED显示屏控制系统的 Yongxian Song宋永献 The Institute of Electronic Engineering Huaihai Institute of Technology Lianyungang，China 淮海工学院电子工程学院 中国 连云港 soyox@126.com Yuan Feng Juanli Ma and Xianjin Zhang The Institute of Electronic Engineering Huaihai Institute of Technology Lianyungang，China soyox@163.com Abstract-This paper introduces display design process about hardware and software based on AT89C52 single chip microcomputer. We use a simple external circuit to control the display screen, which size is 32×192. The display screen also can display the size of the six 32 ×32 dot matrix Chinese characters by a dynamic scan mode, and can be divided into two small display screen, which can display twenty-four Chinese characters whose size is 16×16. We can modify the code to change the content of the display,subtitles can achieve scrolling function and the scroll speed can be adjusted according to requirements, subtitles can also achieve pause function. The Chinese character code stored in external data memory, the capacity of data memory is expanded according to the requirements of Chinese characters we want to show. This display screen has advantages of small volume, few hardware and simple circuit structure. Index Terms-LED, Chinese Character Display, AT89C52 摘要——这篇论文介绍了基于AT89C52单片机关于硬件和软件的显示设计过程。我们用一 个简单的外部电路控制显示屏,其大小为32×192。这个显示屏幕的大小也可以显示六个32×32 点阵汉字动态扫描的模式,可以分为两个小显示屏,可以同时显示24汉字，其尺寸大小是16× 16。我们可以修改这个代码来改变显示的,可以实现根据滚动字幕功能和滚动速度需求 灵活调整,字幕也可以达到停顿功能。汉字代码存储在外部数据存储器,其数据存储能力是 根据我们想要显示汉字的需求进行扩展的。该显示屏具有体积小、硬件少和电路结构简单 的优点。 关键词-LED，汉字显示，AT89C52 I. INTRODUCTION 简介 LED display has become an important symbol of the city lighting, modernization and information society with continuous improvement and beautification of people's living environment [6]. LED lights can be seen in the large shopping malls, railway station, docks, underground station, a variety of management window and so on. LED business has become a fast-growing new industry, a huge market space and bright prospects [9]. The text, pictures, animation and video are displayed by LED's light, and content can be changed. Some components are the display devices of the modular structure, and which usually consists of a display module, control system and power system. The display module is constituted by the lattice structure which consists of LED, and is responsible for light-emitting display; the screen can display text, pictures, video and so on by control system which can control light or dark of LED in the corresponding region;Power system is responsible for transforming input voltage an d current into voltage and current which the screen needs. LED dot matrix display extracted display character font through 1 PC, and sent to the microcontroller, then displayed in the dot matrix screen, which mainly used for display of indoor and outdoor characters. LED dot matrix display can be divided into graphic display,image display and video display by displayed content.Compared with the image display, the characteristics of graphic display is no difference in gray color whether it is monochrome or color display. Therefore, graphic display also fails to reflect the richness of color, and video display can not only show exercise, clear and full-color images, but also show television and computer signals.Although there are some differences between the three,but the most basic principles are similar [6]. LED显示屏已成为一个城市照明、现代化、信息社会与持续改进和美化人们的生活环 境的重要象征[6]。LED灯可以在大型购物商场、车站、码头、地铁站、各种管理窗口等等 地方见到。LED产业已经成为了快速增长的新兴产业,具有巨大的市场空间和应用前景[9]。 文本、图片、动画和视频这些都可以通过LED的光线来显示,并且内容是可以改变的。一些 元器件是模块化结构的显示装置,其通常是由显示模块、控制系统和电力系统组成的。显示 模块是由包含LED的晶体结构组成的，且由其负责发光显示;这个屏幕可以通过控制系统 显示文本、图片、视频等，这些控制系统控制LED在相应的区域亮或灭;电力系统负责将 输入电压和电流转换成屏幕显示所需要的电压和电流。LED点阵显示器通过PC提取显示汉 字的字体,并且传送给单片机，然后显示在点阵屏上,这个显示屏主要用于显示的室内和室外 的人物角色。LED点阵显示器根据显示的内容可分为图形显示、图像显示和视频显示。与 图像显示相比，图形显示的特点是无论它是单色的还是彩色显示的，在灰色显示中没有区 别,。因此,图形显示中也不能反映出丰富的色彩,而视频显示不仅能显示动态、清晰、彩色的 图像,而且也显示电视和电脑的信号。虽然在这三者之间有一些差异,但是最基本的原理是相 似的[6]。 SCM has excellent cost performance, small size, high reliability, strong control, and widely used in smartinstruments, mechanical and electrical integration, real-time process control, robotics, omestic appliances, fuzzy control, communications systems and so on. This article described the design by the LED display relevant principle, and the design of hardware and software structure are described in detail, finally, we simulate for the overall design and analyze the results. 单片机具有良好的性价比，体积小、可靠性高,有较强的控制力,并且广泛应用于智能仪 表、机电一体化、实时过程控制、机器人、家用电器、模糊控制、通信系统等。 本文对LED显示屏设计中的相关原理、硬件设计和软件结构进行了详细的阐述,最后, 我们模拟总体设计和分析的结果。 II. System Overall Structure Design 系统整体结构设计 Single Chip Microcomputer (SCM) models were selected according to the target, function, reliability, cost,accuracy and speed of the control system. According to the actual situation of the subject, the choice of SCM models mainly considered from the following two aspects:First, SCM has strong anti-interference ability; Second,SCM has a higher cost-effective. Due to MCS-51 is widely used in China, has more information and can compatible with the more peripheral chips too, in particular, ATMEL Corporation, introduced a new generation microcontroller in 2003, that is 89S series,and its typical products with high performance and low cost microcontroller is AT89C52. AT89C52 is a low voltage, high-performance CMOS 8-bit microcontroller, the chip includes 8 KB read-only program memory (PEROM) which erase can be repeated, 256byte 2 random access data memory (RAM), devices adopt high-density nonvolatile memory technology to produce, compatible with the standard MCS-51 instruction set and the 8052 products, while the chip built-in general-purpose 8-bit central processing (CPU) , Flash storage unit, can be applied to the more complex control applications[10]. 单片机(SCM)模型的选择是根据目标、功能、可靠性、成本、精度和控制系统的速度。 根据主体的实际情况，单片机(SCM)模型的选择主要考虑以下两个方面:第一,单片机(SCM) 具有较强的抗干扰能力;第二,单片机(SCM)具有较高的性价比。由于在中国mcs—51汇编语 言中得到了广泛的应用,有更多的信息,并且可以配合外围芯片也更多,特别是ATMEL公司在 2003年推出了新一代单片机,即89年代系列,并且其典型产品是具有高性能、低成本的 AT89C52单片机。AT89C52是一个低电压,高性能CMOS 8位的单片机,晶片含有8 k只读存 储器(PEROM)程序可以被重复删除,256字节随机存取数据存储器(RAM),装置采用高密度工 艺生产的非挥发性记忆体,可与标准mcs—51汇编语言指令集以及8052年的产品兼容,而芯 片内置有通用8位中央处理器(CPU)、Flash存储单元,可适用于更复杂的控制应用[10]。 The system was realized by the circuitry which is made up of AT89C52 chip, Clock circuit, reset circuit, column scan driver circuit, line drive circuit and the six 32 x 32 LED dot matrix, the overall structure of LED characters display is shown in Fig.l. A display unit is composed of dot matrix and two 74HC154. Line data signal is divided into two parts, which is given by the two 8255A respectively, but the 8255A data are from the PO port the master controller AT89C52. The column scanning signal of each character was given by the two 74HC154, the 74HC154 12 pieces and was divided into six groups. The input signal of 74HC 154 was given by the PLO-P1.3 of AT89C52. External data memory 6264 connected with the AT89C52 the PO port. 该系统所实现的电路是由AT89C52芯片、时钟电路、复位电路、柱扫描驱动电路、线、 驱动电路和六32×32 LED点阵组成的,LED的整体结构特点如图1。一个显示单元包含点阵 和两个74 HC154。线数据信号分为两个部分,这是由两个8255A分别提供的,但是8255A的 数据老源于PO港口的AT89C52主控制器。每个字符的列扫描信号的是由两个74HC154提 供的,74 HC154 有12件,分为6组。74 HC154所输入的信号是由PLO-P1.3 AT89C52提供的。 外部数据存储器6264与PO港口的AT89C52相联系。 3 III. SYSTEM HARDWARE CIRCUIT DESIGN 系统的硬件电路设计 A. Circuit Design of MCU Control System 单片机控制系统电路的设计 The size of Chinese characters is 32 x 32, but microcontroller has 32 I/O port, and can't meet design requirements, so the I/O port must expand, the data port expansion was implemented by two 8255A. The data port expansion is shown in Fig.2, 74HC373 is the address latch, and latch low eight address, the low eight address signals of 6264 provided by it, but the high eight address signals of 6264 provided by P2.0-P2.4, Internal port of 8255A was chosen by A0 and Al. 74HC139 is 2-4decoder, whose input signals are provided by P2.6 and P2.7 of SCM, and provided strobe for the external I / 0 devices, because the system has more than one external device, make sure that they can not be gated, so that their addresses is the only and do not repeat. The clock circuit of AT89C52 composed of 18, 19 feet from the clock side (XTALI and XTAL2), and 12MHz crystal X, capacitor C1 and C2, and uses on-chip oscillator mode. Reset circuit uses a simple power-on reset circuit, and mainly constitute of resistor RI, capacitor C3, connected to the AT89C52's reset input pin. 汉字字符的大小是32×32,但单片机有32I / O端口,不能满足设计要求,所以I / O端口必 须扩大,数据港口拓展是由两个8255A执行的。数据端口扩展如图2,这个地址门闩是 74HC373,门闩低八地址,低八地址的6264信号是由它所提供的,但高八地址的6264信号是由 P2.O-P2.4所提供的，8255A的内部港口被A0和A1所选择。74 HC139是2-4decoder,其输 入信号P2.6和 P2.7所提供的供应链管理,并提供闸门的外部I/ 0装置,因为这个系统有超过 一个外部设备,确保他们不能被封闭,因此他们的地址是唯一的和不重复的。 AT89C52时钟电路是由18、19英尺的时钟侧(XTALI和XTAL2),和12MHz晶体X,电容 C1和C2所组成的,并使用单片振荡模式。 复位电路使用一个简单的power-on复位电路,并且主要包含电阻RI、电容C3,与AT89C52 4 输入密码重置相联系。 B The Circuit Design of Display Memory Unit 电路设计的显示存储单元组成 The size of Chinese characters is 32x32 in the design, each character composed of four parts which are (a), (b), (c), and (d), and each part composed of four LED matrix which the size is 8 x 8, circuit decomposition map of display unit is shown in Fig.3. The line signals of (a)~(b) are given by two 8255A, 1 PA0 -1 PA7 and 1 PB0-4PB7 are PA and PB port of 8255A-1，2PA0 - 2PA7 and 2PB0 - 2PB7 are PA and PB port of 8255A-2, the right figures represent column scan signals which is given by 74HC 154. 16 column strobes are provided by 74HC154, (a) - (d) requires eight signal, respectively, so (a) and (b) share a 74HC 154, (c) and (d) shared a 74HC154. Display a character need two 74HC154 which provide column scan signals. When the circuit works, the (a) - (d) is gated by scanning signal in proper order, only one was gated at a time, and other columns are extinguished, the displayed data is given by two pieces of 8255A simultaneously, the human eye will see a stable character because of the human eye's persistence of vision. In addition, because the Chinese character for each display needs 128 bytes storage space, but AT89C52 microcontroller chip is only 256 bytes data memory, it is far less than the design requirements, so we expanded the storage space by 8K x 8 external data memory 6264. 在设计过程中汉字是大小的32 x32,每个字符由四个部分所组成，它们是(a),(b),(c),(d), 并且每一个部分由4个矩阵的大小是8×8的LED所组成，显示单元的电路分解图如图3。 (a)~(b)的线信号两个8255A所提供的,1PAO0-1 PA7和1 PB0-4PB7是8255A-1相应的端口PA 和PB，2 PA0- 2PA7和2PB0 - 2PB7是8255A-2相应的的端口PA和PB,正确的数据代表扫 描信号柱给出了HC 154。16个柱闸门是由74HC154所提供的,(a)-(d)各自需要八个信号,所 以(a)和(b)共享一个74 HC 154,(c)和(d)共享一个74 HC154。显示一个字符需要两个74 HC154 5 列扫描提供信号。当电路工作时,(a)-(d)是通过扫描信号封闭排序的,一次只排列一个,而其他 的柱熄灭,显示的数据是由两块8255 A同时给出,由于人的眼睛具有视觉暂留的特点，因而人 的眼睛会看到一个稳定的字符。此外,因为显示每一个汉字需要128字节的存储空间,但 AT89C52单片机芯片只有256字节数据存储器,它远低于设计要求,所以我们通过8 K×8外部 数据存储器6264来扩展存储空间。 C The Design of Ranks Data Unit Circuit 等级数据单元的设计电路 Intel 8255A is a universal programmable parallel input/output interface chip. Its function can be set through the software program, and has a strong versatility. It can be directly through the 6 CPU data bus connected to external devices, easy to use and flexible. Inte18255A interface chip has three 8-bit parallel input and output ports, programming methods can be used to set three ports as input ports or output ports. Chips work have the basic input and output, strobe input/output and bidirectional input / output. When the data were transmitted by data bus of CPU, its can choose to unconditionally transfer, query transmission or interrupt transmission. During Intel 8255A chip three-port, the port C can be used as not only the data port, but also the control port. When the port C is taken as a data port, it can be used as not only 8-bit data port, but also separately as two 4-bit data port, and each bit of the port C can be operated, can set a particular bit to input or output, so provide convenient conditions for bits control. 英特尔8255 A是一种通用可编程并行输入/输出接口芯片。其功能可以通过软件程序设 定,具有很强的通用性。它可以直接通过中央处理器数据总线连接到外部设备,使用方便、灵 活。Inte18255A接口芯片有三个8位并行的输入和输出端口,编程方法可以被用于设置三个 端口作为输入端口或输出端口。芯片工作都有基本的输入和输出,闸门输入/输出和双向输入/ 输出。当这些数据被传输的数据总线上的CPU时,其可选择无条件转让、查询传输或中断传 输。在英特尔8255A芯片三个端口中,端口C不仅可作为数据端口,而且可作为控制港口。当 端口C作为数据端口时,它不仅可以作为8位数据端口,而且也分别作为两个4位的独立数据 端口,每一个端口C的位都可以被操控,可以设定一个特定的位去输入或输出,因此对位控制 提供了便利的条件。 In design of the display unit circuit, the lines data are given by two 8255A, as is shown in Figure 4. This design uses dynamic display means to display Chinese characters, which can be controlled the by the means of line or column scanning, The system uses the method of column scanning to control screen, Specific column scanning circuit is shown in Figure 5. Column 7 scanning circuit composed of 12 pieces of 74HC154.Two pieces of 74HC154 provided 32 strobes to display a character. The input signal of 74HC 154 is P 1.0 - P 1.3 which is provided by AT89C52 to control screen, but 12 pieces of 74HC 154 were used in the design, they work according to the order, the input of another piece of 74HC 154 is P IA - P1.7 which is provided by AT89C52 to control screen. 在显示单元电路的设计,线数据是由两个8255A所给出的,如图4所示。该设计采用动态 显示方式显示汉字,而这可以通过行或列扫描方式来控制,该系统采用柱的方法来控制屏幕扫 描,扫描电路的具体情况如图5所示。列扫描电路是由12个74 HC154组成的 。两块74 HC154 提供32 次闪光来显示一个字符。74 HC154的输入信号是P 1.0- P 1.3，其是由AT89C52来 控制屏幕,但在设计过程中使用了12块74 HC154,他们的工作是根据这个秩序进行的,另一块 74 -HC154的输入是PIA-P1.7，并且由AT89C52所提供的P1.7来控制屏幕。 8 D Serial Communication Interface Circuit 串行通信接口电路 PC and SCM are linked via a serial communication interface. In order to implement serial conununication function between MCU and PC, and serial interface level of SCM will be changed into standard RS-232C level [ 11 ]. Where the output voltage of PC's RS-232C port is 1 12V. MCU and PC, taking into account the short distance communication, and microcontroller is mainly responsible for receiving commands and data, so the PC is directly connected with the microcontroller, this is the simplest connection method. the signals which is from PC's TXD-side were changed into a current signal through the communication circuit, the infrared light-emitting diodes of optocouper have current when a signal occurs, the light signals which is emitted by diode projected onto the phototransistor, and converted to electric signal, then input to the microcontroller RXD side, so photoelectric conversion is implemented, and electrical is completely isolated to avoid the feedback and interference which is produced by output side. as is shown in Figure 6 PC和单片机是通过一个串行通信接口连接在一起的。为了实现单片机和PC的串行通 信函数功能,单片机串行接口水平将会变成标准RS - 232 - C水平[11]。在PC机的输出电压 的RS - 232 C端口是12伏。单片机和PC,考虑到短距离通信,单片机主要负责接收的命令和 数据,所以在PC直接关系到单片机,这是最简单的关联方法。信号从PC机的TXD-side被改 变成一个电流信号通过通信电路、红外发光二极管的电流optocouper 当有信号发生时,二极 管发出的光信号通过光敏三极管投射,并转换为电信号,然后输入到单片机RXD身边,因而光 电转换得以实现,并且电气完全隔离以避免输出端所产生反馈和干扰。如图6所示。 IV. SOFTWARE DESIGN 软件设计 The entire software design mainly composes of display program and communication program. The Chinese characters to be displayed on the screen,character and other data for transmission control and display functions were achieved by dynamic scan. Real-time communication parts which communicate with PC receive data information by SCM serial disruption, so real-time data 9 information transmission with PC was implemented. The host computer software was implemented by Visual Basic. In the standard serial communication,MSCOMM which is the power communication control is provided by VB, it can set the serial communication of data sent and received, and the serial communication port status, message formats and protocols are set, directly send data by PC's RS -232/RS-485 serial port. In order to realized to PC reliable communication with SCM, and ensure that both sides have the same data format and baud rate [11], this design uses RS-232 communications,a 10 bits data format. 9600bit / s baud rate. 整个软件设计的主要构成包括显示程序和通信程序。汉字显示在屏幕上,字符和其他数 据的传输、控制和显示功能则是通过动态扫描实现的。与PC通信的实时通信部件是通过单 片机串行干扰信息来接收数据的,所以与PC之间实时数据信息的传输才得以执行。 主机软件是通过视觉化Basic程式语言实施的。在标准串行通讯中,电力通信MSCOMM 是由VB控制的,它可以设置串行通讯的数据发送和接收、串行通讯端口状态,消息和协 议,直接用PC发送数据RS / RS—485的串行端口。为了实现PC与单片机的可靠的通讯,确 保双方都有相同的数据格式和传输速率[11],该设计采用RS - 232通讯,一种10位数据格式。 9600位/秒传输速率。 A Principles of Chinese characters dot matrix display and Sub-codes 汉字的原则和Sub-codes 点阵显示 Chinese Times New Roman font which is UCDOS was taken as an example, each word composed of 16 x 16 dot matrix. That is, every word of the national standard Chinese character library expressed by the 256 lattice.We can understand each point as a pixel, and the shape of each word understood as an image. In fact, this character display screen not only can display Chinese characters, but also can display any graphics within the scope of 256 pixels. Due to the bus of microcontroller is the 8-bit, and a word need to split into two parts, as is shown figure 7. UCDOS曾以华夏时报新罗马字体为例,每一个字是由16×16的点阵所组成的。那也就 是说,国家标准中文图馆的每一个字都是由256格所表达的。我们可以理解每一个点作为 一个像素,每个单词的形状理解为一个图像。事实上,这个字符显示屏不仅能显示汉字,而且可 以显示在256像素范围内的任何图形。由于汽车是8位的单片机,并且一个词需要分成两部 分,如图7所示。 10 In order to understand Chinese characters dot matrix composition law, at first, the characters code was obtained by column scanning method. Chinese characters are divided into upper part and lower part, the upper part composed of 8 x16 lattice, the lower part was also formed by the 8 x 16 lattice. The first column of the upper left corner which was the upper part was shown by Column scanning method first, namely, POO-P07 port of 0 column, direction was POO-P07, Chinese character for "large" was displayed, P05 was on, the other is off. That is, binary is 00000100, and convert to hexadecimal as 04h.After the first column of the upper part was over, and continue to scan the bottom half of the first column, It can be seen from Figure 7, this column is not on all, that is, binary was 00000000, hex was 00h. According to this method, the second column, third column, until the sixteenth was scanned in turn. Characters "big" scan code can be drawn. 为了了解点矩阵组成汉字的规则,首先,字符代码是通过列扫描方法得到的。汉字分为上 半部分和下半部分,上方8×16格子组成的,下半部分也由8×16的晶格组成。坐上角落的第 一列是通过第一次列扫描方法所得到的上半部分，即P00-P070列端口、方向为P00-P07,从 而汉字“大”才被显示,P05是开着的,而另一个是关闭的。那也就是说,代码是00000100,并 转换为十六进制如04 h。在第一列上方结束之后,继续扫描下半身的第一列,如图7所示,此列 并不是全部开着的,即二进制是00000000,十六进制是00 h。根据这种方法,第二列,第三列,直 到十六列依次被扫描。从而可以得出“大”字的扫描码。 04H, 00H, 04H, 02H, 04H, 02H, 04H, 04H 04H, 08H, 04H, 30H, 05H, 0C0H, 0FEH, 00H 05H, 80H, 04H, 60H, 04H, l0H, 04H, 08H 04H, 04H, 0CH, 06H, 04H, 041-1,001-1, 00H It can be seen from this principle, no matter what font or image display, we can use this method to analyze the scan code and appears on the screen. Although above methods allow us to figure out the code for character dot-matrix process, but rely on manual methods for character code is a very complicated matter.To this end, Font software is used to find the character code, the content to display is entered after the software opens, font and size can be chosen according to requirements, you can select modulo by row or by column. Press the modulus button, the hexadecimal data character code can be automatically generated, we need to copy the data into the program. 可以从这一原则看出,不管显示什么字体和图像,我们都可以用这些方法去分析扫描代码 和显示在屏幕上。 虽然上述方法使我们能够找出点阵字符代码的过程,但是依靠手动为字符编码是一个非 常复杂的问题。为此,字体软件是用来发现字符代码,输入显示的内容是在软件打开之后,字体 和大小可根据要求选择,你可以根据行或列来选择模数。按模按钮,十六进制字符编码数据可 以自动生成,我们需要将数据拷贝到这个程序中。 11 B. Address Assignment the Port and Data Memory 地址分配港口及数据存储器 In this design, we used to 8255A, 6264 and other external devices, and their gating is not the same, so strobe is controlled, which involves the address allocation problem. In the system, the address code of 8255A is 3FFCH - 3FFFH and 7FFCH - 7FFFH, the address code of 6264 is 0A000H - 0BFFFH. In addition, memory 6264 is divided into four zones, each space size is 2K, the corresponding address code is 0A000H - 0A7FFH,0A800H - 0AFFFH, 0B000H - 0B7FFH, 0B800H 0BFFFH respectively. Table 1 and table 2 show the address allocation of the 8255A and 6264 respectively. 在这个设计中,我们习惯于8255A、6264和其他外部设备,并且他们的浇注是不同的,所以 闸门被控制着,包括地址分配问题。在系统中，8255A的详细地址编码是3FFCH- 3FFFH和 7FFCH - 7 FFFH，6264的地址代码是0A000H - 0BFFFH。此外,记忆6264分为四个不同的 区,每个空间大小是2 K,相应的地址代码是0A000H - 0A7FFH,0A800H-0 AFFFH ,0B000H-0 B7FFH ,0B800H -0BFFFH。表1和表2表明8255A和6264A各自的地址分配情况。 12 C. Software process 软件程序 Software program composed of the beginning,initialization, display program, front, which the main program and subroutine flow chart are shown in Figure.8.and Figure 9. Character code stored in the static memory 6264, and the SCM will wait for signal is given, that is,the input signal of SCM pin P3.0. When P3.0 is from low to high, display program begin to be run. First, control words written to 8255A control port, 8255A work in the form of mode 0 in the design. After control word was finished, the data will be displayed which is transferred to the 8255A from the 6264, the display data is output for four times because the line width of the characters screen is 32, a row of data is input and transported from top to bottom each, signal of the first rows which is controlled by SCM is gated after data transmission is over, so the first column data is displayed, then call delay procedures to display the contents of the stable. the next column of data is read after delay procedures is over, and the next row is gated, so that the second column of data is also displayed, and so on, because the screen size is 32 x 192,192 rows are shown, and 192 rows constitute an image.Then, scanning begin from the first column, and the starting address of display data backward shift on the basis of the original, which has an address overflow issues, it will assign start address to the address pointer when the data address is overflow, the display data content will be constantly repeated. Flow chart of communication with PC and SCM is shown in Figure 10. Real-time communication parts which communicate with PC receive data information by SCM serial disruption, so real-time data information transmission with PC was implemented. 软件程序是由初始化,显示程序,战线组成，主程序和子程序的流程图如图8和图9所示。 字符代码的静态存储在内存6264,配置管理工具将等待信号给出,即对单片机应用针P3.0输 入信号。当P3.0是由低到高时,显示程序开始运行。首先,控制向8255A控制端口所写的字, 在设计中8255A以模式0的形式工作。控制字完成后,数据将显示,并且会从6264转移到 13 8255A，由于字符屏幕的线宽32，所以显示数据输出4次,每一排的数据输入和从上到下传输,每个第一排信号是由单片机在数据传输结束后控制的,所以第一栏数据显示,然后要求延迟程序来显示稳定的内容。第二列数据在延迟程序结束后阅读,第二行是封闭的,所以第二列里的数据也显示,等等,因为屏幕尺寸是32×192，192行显示,192行构成一幅图像。然后,扫描从第一列,并且开始地址在显示原来的数据的基础上向后移动,其有一个地址溢出的问题,当数据的地址溢出时就将指定的地址指针安排为开始地址,显示数据内容会不断重复。 流程图和单片机与PC通讯如图10。通过单片机串行干扰信息来实现实时通信部件与电脑之间接收数据信息 ,所以与PC实时数据信息的传输才得以执行。 14 15 V. SIMULATION RESULTS AND ANALYSIS 模拟实验结果与分析 After the hardware and software design finished, the content of the design was simulated by Proteus, and modify circuit or optimize the program according to the simulation results. Proteus software which is EDA tool software is published by the British Labcenter electronics companies (the software agent in China is the Guangzhou Electronic Technology Co. Ltd. vane) [7]. It not only has simulation functions of other EDA tools, but also simulates microcontrollers and peripheral devices. It is the best simulation tool for microcontroller and external device. Although the Proteus just started in the domestic, lovers of SCM, the teachers of teaching in SCM and science and technology workers which engaged in SCM all love this software. Proteus is the world's leading EDA tools (simulation software), from the schematic layout,debugging code to the MCU and the external circuit co-simulation, a key switch to the PCB design, complete design was realized from concept to product. It Is only simulation software platform which is composed of circuit simulation software, PCB design software and the virtual model, the processor model supports 8051, HC 11,PIC10/12/16/18/24/30/DsPIC33, AVR, ARM, 8086, and MSP430, etc. Cortex and the DSP family of processors were increased in 2010, and will increase other series processor model. In the compilation side, it also supports IAR, Keil and MATLAB and so on. 16 在完成了系统的硬件和软件设计完成后，通过Proteus软件来模拟内容的设计,并修改电 路或优化程序根据仿真结果。EDA工具软件,它是是由英国Labcenter电子公司发布的Proteus 软件(软件在中国的代理商是广州市电子技术有限叶片式)[7]。它不仅具有其他EDA工具的 仿真功能,还具有模拟微控制器和周边设备的功能。这是最好的仿真工具和外部设备单片机。 虽然在国内Proteus软件才刚开始，单片机的爱好者、教授单片机的教师和从事单片机研究 的科技工作者都爱这个软件。Proteus软件是世界领先的EDA工具(仿真软件),从规划、 调试代码,采用单片机和外部电路仿真,一键切换到PCB设计、完整的设计,实现了从概念到 产品。只有仿真软件平台,才包含电路仿真软件,PCB设计软件和虚拟模型,处理器模型支持 8051、HC 11、PIC10/12/16/18/24/30 / DsPIC33、AVR、手臂、8086、节流等。皮层和高速 DSP家庭处理器在2010年得以增加，并且增加其它系列处理器模型。在编辑的方面,它也支 持IAR,凯尔和MATLAB等等。 A PCB design and component assembly PCB设计和组件组装 Taking into account the number of components used in this design is not too much, we used the single routing strategy, and use a small amount of jumper wires on the top floor. The circuit are not stringent requirements for components parameters, as long as the component selection is correct, no damage, good circuit board manufacturing process, all electronic components can be assembled into the correct welding procedure, and to download program and debug program. When PCB board was produced and debugged, IC that is 20 pin should be installed in the AT89C52 position, in order to the microcontroller can take down from the circuit board,and write program. 考虑到用于设计的组件数量不是太多,我们使用单一的路由策略,在顶层使用少量的跳线 开关电线。这个电路元件参数没有严格的要求,只要组件的选择是正确的，无损伤，良好的 电路板生产过程,所有的电子元件都可以组装成正确的焊接工艺,并下载程序和调试程序。当 线路板被生产和调试、集成电路(IC)那是20pin应安装在AT89C52的位置,为了从单片机可 以击落电路板,并且写程序。 B Simulation 仿真 Scroll of Chinese characters was implemented by software programming, we take a whole series of images which was implemented by Column scan signals to a frame, here is 192 rows. Then the next frame data backward shift on the basis of the first frame data, and dynamic display can be generated. The images result of the simulation is shown in Figure 11. 汉字是由软件编程实现,我们采取了一系列的图像,通过列扫描信号到一个框架来实现的, 这里是192行。接下来的一个帧在转移数据的基础上落后第一帧数据,可以生成动态显示。 图像的仿真结果如图11所示。 17 The simulation results shows that simulation is consistent with theoretical analysis, the data distribution of the memory is correct, the data correctly stored into the data memory, the display shows the contents of the program is the data to be displayed, the display can also be achieved pause and display speed is adjustable,indicating that the design of the hardware and software are possible. After the compilation and simulation of program was accomplished, preparing an editor that can write the AT89C52, and connected with the host computer hardware, that is, we can write AT89C52 chip and download, then, the microcontroller AT89C52 which is written program insert into the IC that has 40 pins. When power is connected, we can debug and run. As the system circuit require for parameters of the components is not very high, as long as the device is better, the parameters can meet the requirements, and work immediately after welding assembly. 仿真结果表明:仿真与理论分析是一致的,记忆的数据分布是正确的,数据正确的存入数 据存储器,显示器显示程序的内容是数据将会被显示,显示器也能达到停顿和显示速度可调, 表明设计的硬件和软件都是可能的。 在编辑和仿真的程序完成之后,准备一个可以写AT89C52的编辑器,且与主机计算机硬 件相连接，那就是,我们可以写AT89C52芯片和下载,然后,在单片机AT89C52插入有40个帧 的IC的书面程序。当动力连接时,我们可以编译和运行。 由于系统电路需要组件的参数不是很高,只要该装置较好,能够满足要求的参数,在焊接 装配后能立即工作。 VI. CONCLUSION 结论 LED display system that was designed adopted the host computer and slave structure, the host computer is PC, and communicated with slave computer display system through the serial communication interface, which can implement string modification, display mode settings,time settings and other functions; The slave mainly implement display of LED dot matrix display screen which was controlled by SCM. Chinese character display is 32 x32 dot matrix model, and to achieve real-time screen display changes, and have to display the current time and date functions. The design of LED dot matrix display control system has a simple circuit, stability, low power consumption, long life, easy to display characteristics, and include the LED display basic principles and procedures. As long as the microcontroller I/O interface is expanded, and increase the number of LED dot matrix and related chips, you can design a larger area and 18 more tricks of the LED display. This article has some reference value of theory and practice. As the core control unit of the system, that is AT89C52, has lower frequency, in the future, in order to achieve LED video display in real time, and the display image can be compressed, which will increase the burden on the system. We can take advantage of high-speed DSP as the core control unit, and solve the above mentioned problems. LED显示系统的设计采用了主机和从属结构，主机是PC，把电脑显示器和从属系统通 过串行接口通信,它可以实现字符串修改，展示模式设置,时间设置和其他功能;LED点阵显 示屏主要执行辅助显示，且其由单片机所控制。汉字显示是32 x32点阵模型，实现实时屏 幕显示的变化，必须实现显示当前的时间和日期的功能。设计LED点阵显示控制系统具有 电路简单、稳定、低功率消耗、寿命长、易显示的特征,并且包括LED显示屏的基本原则和 程序。只要单片机的I / O接口扩展,提高LED点阵的数量及相关芯片,你就可以掌握设计一 个更大的面积和更多LED显示屏的窍门。这篇文章有一定理论与实践的参考价值。 作为核心控制单元的系统,那就是AT89C52，其具有较低的频率,在未来,为了实现实时视 频显示,并且显示图像可以被压缩,这将会增加系统的负担。我们可以利用高速DSP为核心控 制单元,解决上述问题。 ACKNOWLEDGMENT 感谢 The authors wish to thank Zhang xianjin and Fan Jishan for providing critical comments for this study and QiuXiuLing for editorial assistance. 作者希望感谢张先进和樊继山对这篇论文所提出了宝贵的意见，以及感谢丘秀玲对编辑工作 的帮助。 REFERENCES 参考文献 [1] Zhou Mingde. Principle and Application of MicroComputer Systems[ M].Beijing: Tsinghua University Press, 2007 [2] Chen Junxia, Huang Yuehua, Gan Wen. Large-screen LED dot matrix display system[J]. Automation Technology and Application. 2007, 26 (7) : 118-120. [3] Yan Shi. Digital Electronic Technology [M]. Beijing: Higher Education Press, 2006 [4] Gu Deying, Luo Yunlin,Ma Shuhua. 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