為解決傳統(tǒng)可視倒車(chē)?yán)走_(dá)視頻字符疊加器結(jié)構(gòu)復(fù)雜,可靠性差,成本高昂等問(wèn)題,在可視倒車(chē)?yán)走_(dá)設(shè)計(jì)中采用視頻字符發(fā)生器芯片MAX7456。該芯片集成了所有用于產(chǎn)生用戶定義OSD,并將其插入視頻信號(hào)中所需的全部功能,僅需少量的外圍阻容元件即可正常工作。給出了以MAX7456為核心的可視倒車(chē)?yán)走_(dá)的軟、硬件實(shí)現(xiàn)方案及設(shè)計(jì)實(shí)例。該方案具有電路結(jié)構(gòu)簡(jiǎn)單、價(jià)格低廉、符合人體視覺(jué)習(xí)慣的特點(diǎn)。經(jīng)實(shí)際裝車(chē)測(cè)試,按該方案設(shè)計(jì)的可視倒車(chē)?yán)走_(dá)視場(chǎng)清晰、提示字符醒目、工作可靠,可有效降低駕駛員倒車(chē)時(shí)的工作強(qiáng)度、減少倒車(chē)事故的發(fā)生。 Abstract: A new video and text generation chip,MAX7456,was used in the design of video parking sensor in order to simplify system structure,improve reliability and reduce cost. This chip included all the necessary functions to generate user-defined OSDs and to add them into the video signals. It could be put into work with addition of just a small number of resistances and capacitors. This paper provided software and hardware implementation solutions and design example based on the chip. The system had the characteristics of simplicity in circuit structure,lower cost,and comfort for the nature of human vision. Loading road test demonstrates high video and text display quality and reliable performance,which makes the driver easy to see backward and reduces chance of accidents.
標(biāo)簽: 7456 MAX 可視倒車(chē) 中的應(yīng)用
上傳時(shí)間: 2013-12-10
上傳用戶:qiaoyue
本文介紹了基于AT89C52 單片機(jī)的自動(dòng)水溫控制系統(tǒng)的設(shè)計(jì)及實(shí)現(xiàn)過(guò)程。該系統(tǒng)具有實(shí)時(shí)顯示、溫度測(cè)量、溫度設(shè)定并能根據(jù)設(shè)定值對(duì)環(huán)境溫度進(jìn)行調(diào)節(jié)實(shí)現(xiàn)控溫的目的以及達(dá)到上下限溫度報(bào)警功能,控制算法是基于數(shù)字PID 算法。關(guān)鍵詞 :PID AT89C52 脈寬調(diào)制 實(shí)時(shí) Abstract : This article describes AT89C52 single-chip microcomputer-basedautomatic water temperature control system design and implementation process. Thesystem has real-time display, temperature measurement, temperature settings and theenvironment in accordance with the temperature settings adjusted to achieve thepurpose of temperature control and reach the upper and lower limits of temperaturealarm function, the control algorithm is based on the digital PID algorithm.Keyword: PID AT89C52 PWM real time
上傳時(shí)間: 2013-10-10
上傳用戶:歸海惜雪
Virtex-5, Spartan-DSP FPGAs Application Note This application note demonstrates how efficient implementations of Digital Up Converters(DUC) and Digital Down Converters (DDC) can be done by leveraging the Xilinx DSP IPportfolio for increased productivity and reduced time to development. Step-by-step instruction is given on how to perform system-level trade off analysis and develop the most efficient FPGA implementation, thus allowing engineers a flexible, low-cost and low-power alternative to ASSP technologies.
標(biāo)簽: Spartan-DSP Virtex FPGAs Ap
上傳時(shí)間: 2013-10-23
上傳用戶:raron1989
This document describes the system hardware implementation for the OMAP3530 processor and theTPS65930/20 companion power integrated circuit (IC). The document concentrates on the powerconnectivity for the processor and the companion power IC. The document also briefly explains someother specifics related to power, such as the boot modes and the power-up sequence.
標(biāo)簽: TPS 65930 65920 3530
上傳時(shí)間: 2013-11-14
上傳用戶:yeling1919
Using the XGATE for Manchester DecodingTable of Contents 1 Introduction 1.1 XGATE Module in S12X 2 Decoding Algorithm 3 Software Implementation 3.1 Frame Scheme 3.2 Operating Modes and Demo 3.3 Files Summary 3.4 Complete Mode Flowchart 4 Manchester Encoder 4.1 Devices Used 5 Conclusion Appendix A Noise Elements During RF Transmissions in the Manchester Decoding ImplementationA.1 Types of Noise A.2 Effects of Noise A.3 Workaround for Noise Effects
標(biāo)簽: Manchester XGATE 譯碼
上傳時(shí)間: 2013-10-15
上傳用戶:wqq123456
1.The C Programming Language is a powerful, flexible andpotentially portable high-level programming language. 2.The C language may be used successfully to create a programfor an 8-bit MCU, but to produce the most efficient machinecode, the programmer must carefully construct the C Languageprogram.3.The programmer must not only create an efficient high leveldesign, but also pay attention to the detailed implementation.
標(biāo)簽: FREESCALE 單片機(jī) 編程 教程
上傳時(shí)間: 2013-12-27
上傳用戶:huanglang
匯編器在微處理器的驗(yàn)證和應(yīng)用中舉足輕重,如何設(shè)計(jì)通用的匯編器一直是研究的熱點(diǎn)之一。本文提出了一種開(kāi)放式的匯編器系統(tǒng)設(shè)計(jì)思想,在匯編語(yǔ)言與機(jī)器語(yǔ)言間插入中間代碼CMDL(code mapping description language)語(yǔ)言,打破匯編語(yǔ)言與機(jī)器語(yǔ)言的直接映射關(guān)系,由此建立起一套描述匯編語(yǔ)言與機(jī)器語(yǔ)言的開(kāi)放式映射體系。基于此開(kāi)放式映射體系開(kāi)發(fā)了一套匯編器系統(tǒng),具有較高層次上的通用性和可移植性。【關(guān)鍵詞】指令集,CMDL,匯編器,開(kāi)放式 Design of Retargetable Assembler System Liu Ling Feng Wen Nan Wang Ying Chun Jiang An Ping Ji Li Jiu IME of Peking University, 100871【摘要】An assembler plays a very important role in the field of microprocessor verifications and applications, thus how to build a retargetable assembler system has been a hotspot in this field for long time. This paper presents a new method about the retargetable assembler system design.It provides a kind of language CMDL, code mapping description language. During the process of assembling, assembler languages are firstly translated to CMDL, and then mapped to the machine codes. In an other word, CMDL is inserted between assembler languages and machine codes during the translation procedure. As a medium code, CMDL has a lot of features, such as high extraction, strong descript capabilities. It can describe almost all attributes of assembler languages. By breaking the direct mapping relationship between assembler languages and machine codes, the complexities of machine codes are hided to the users, therefore, the new retargetable assembler system has higher retargetable level by converting the mapping from assembler languages and machine codes to assembler languages and CMDL, and implementationof it becomes easier. Based on the new mapping system structure, a retargetable assemblersystem is developed. It proved the whole system has good retargetability and implantability.【關(guān)鍵詞】instruction set, symbol table, assembler, lexical analysis, retargetability
上傳時(shí)間: 2013-10-10
上傳用戶:meiguiweishi
基于單DSP的VoIP模擬電話適配器研究與實(shí)現(xiàn):提出和實(shí)現(xiàn)了一種新穎的基于單個(gè)通用數(shù)字信號(hào)處理器(DSP)的VoIP模擬電話適配器方案。DSP的I/O和存儲(chǔ)資源非常有限,通常適于運(yùn)算密集型應(yīng)用,不適宜控制密集型應(yīng)用[5]。該系統(tǒng)高效利用單DSP的I/O和片內(nèi)外存儲(chǔ)器資源,采用μC/OS-II嵌入式實(shí)時(shí)操作系統(tǒng),支持SIP和TCP-UDP/IP協(xié)議,通過(guò)LAN或者寬帶接入,使普通電話機(jī)成為Internet終端,實(shí)現(xiàn)IP電話。該系統(tǒng)軟硬件結(jié)構(gòu)緊湊高效,運(yùn)行穩(wěn)定,成本低,具有廣闊的應(yīng)用前景。關(guān)鍵詞:模擬電話適配器;IP電話;數(shù)字信號(hào)處理器;μC/OS-II 【Abstract】This paper presents a VoIP ATA solution based on a single digital signal processor (DSP). DSPs are suitable for arithmetic-intensiveapplication and unsuitable for control-intensive application because of the limitation of I/O and memory resources. This solution is based on a 16-bitfixed-point DSP and μC/OS-II embedded real-time operating system. It makes good use of the limited resources, supports SIP and TCP-UDP/IPprotocol. It can connect the analog telephone to Internet and realize the VoIP application. This system has a great future for its high efficiency andlow cost.【Key words】Analog telephone adapter (ATA); Voice over Internet protocol (VoIP); Digital signal processor (DSP); μC/OS-II Research and Implementation of VoIPATA Based on Single DSP
上傳時(shí)間: 2013-11-20
上傳用戶:Wwill
The C500 microcontroller family usually provides only one on-chip synchronous serialchannel (SSC). If a second SSC is required, an emulation of the missing interface mayhelp to avoid an external hardware solution with additional electronic components.The solution presented in this paper and in the attached source files emulates the mostimportant SSC functions by using optimized SW routines with a performance up to 25KBaud in Slave Mode with half duplex transmission and an overhead less than 60% atSAB C513 with 12 MHz. Due to the implementation in C this performance is not the limitof the chip. A pure implementation in assembler will result in a strong reduction of theCPU load and therefore increase the maximum speed of the interface. In addition,microcontrollers like the SAB C505 will speed up the interface by a factor of two becauseof an optimized architecture compared with the SAB C513.Moreover, this solution lays stress on using as few on-chip hardware resources aspossible. A more excessive consumption of those resources will result in a highermaximum speed of the emulated interface.Due to the restricted performance of an 8 bit microcontroller a pin compatible solution isprovided only; the internal register based programming interface is replaced by a set ofsubroutine calls.The attached source files also contain a test shell, which demonstrates how to exchangeinformation between an on-chip HW-SSC and the emulated SW-SSC via 5 external wiresin different operation modes. It is based on the SAB C513 (Siemens 8 bit microcontroller).A table with load measurements is presented to give an indication for the fraction of CPUperformance required by software for emulating the SSC.
標(biāo)簽: synchronous Emulating serial
上傳時(shí)間: 2014-01-31
上傳用戶:z1191176801
The μPSD32xx family, from ST, consists of Flash programmable system devices with a 8032 MicrocontrollerCore. Of these, the μPSD3234A and μPSD3254A are notable for having a complete implementationof the USB hardware directly on the chip, complying with the Universal Serial Bus Specification, Revision1.1.This application note describes a demonstration program that has been written for the DK3200 hardwaredemonstration kit (incorporating a μPSD3234A device). It gives the user an idea of how simple it is to workwith the device, using the HID class as a ready-made device driver for the USB connection.IN-APPLICATION-PROGRAMMING (IAP) AND IN-SYSTEM-PROGRAMMING (ISP)Since the μPSD contains two independent Flash memory arrays, the Micro Controller Unit (MCU) can executecode from one memory while erasing and programming the other. Product firmware updates in thefield can be reliably performed over any communication channel (such as CAN, Ethernet, UART, J1850)using this unique architecture. For In-Application-Programming (IAP), all code is updated through theMCU. The main advantage for the user is that the firmware can be updated remotely. The target applicationruns and takes care on its own program code and data memory.IAP is not the only method to program the firmware in μPSD devices. They can also be programmed usingIn-System-Programming (ISP). A IEEE1149.1-compliant JTAG interface is included on the μPSD. Withthis, the entire device can be rapidly programmed while soldered to the circuit board (Main Flash memory,Secondary Boot Flash memory, the PLD, and all configuration areas). This requires no MCU participation.The MCU is completely bypassed. So, the μPSD can be programmed or reprogrammed any time, anywhere, even when completely uncommitted.Both methods take place with the device in its normal hardware environment, soldered to a printed circuitboard. The IAP method cannot be used without previous use of ISP, because IAP utilizes a small amountof resident code to receive the service commands, and to perform the desired operations.
標(biāo)簽: Demonstration 3200 USB for
上傳時(shí)間: 2014-02-27
上傳用戶:zhangzhenyu
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