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Digital convergence, in recent history, has been prevalentin the consumer equipment domain and the designengineers in this area have been struggling with a plethoraof emerging standards and protocols. What lessons can welearn from their struggle? The same dilemmas now existin in-vehicle telematics and infotainment systems but withthe added issues of extremes of temperature, safety,security, and time in market.
標(biāo)簽： 遠(yuǎn)程信息處理 數(shù)字 協(xié)議 標(biāo)準(zhǔn)
上傳時(shí)間： 2014-12-23
上傳用戶：9牛10
Recent advances in low voltage silicon germaniumand BiCMOS processes have allowed the design andproduction of very high speed amplifi ers. Because theprocesses are low voltage, most of the amplifi er designshave incorporated differential inputs and outputs to regainand maximize total output signal swing. Since many lowvoltageapplications are single-ended, the questions arise,“How can I use a differential I/O amplifi er in a single-endedapplication?” and “What are the implications of suchuse?” This Design Note addresses some of the practicalimplications and demonstrates specifi c single-endedapplications using the 3GHz gain-bandwidth LTC6406differential I/O amplifi er.
標(biāo)簽： 單端應(yīng)用 差分 放大器
上傳時(shí)間： 2013-11-23
上傳用戶：rocketrevenge
PCB設(shè)計(jì)問題集錦 問：PCB圖中各種字符往往容易疊加在一起，或者相距很近，當(dāng)板子布得很密時(shí)，情況更加嚴(yán)重。當(dāng)我用Verify Design進(jìn)行檢查時(shí)，會(huì)產(chǎn)生錯(cuò)誤，但這種錯(cuò)誤可以忽略。往往這種錯(cuò)誤很多，有幾百個(gè)，將其他更重要的錯(cuò)誤淹沒了，如何使Verify Design會(huì)略掉這種錯(cuò)誤，或者在眾多的錯(cuò)誤中快速找到重要的錯(cuò)誤。 答：可以在顏色顯示中將文字去掉,不顯示后再檢查;并記錄錯(cuò)誤數(shù)目。但一定要檢查是否真正屬于不需要的文字。 問： What’s mean of below warning:(6230,8330 L1) Latium Rule not checked: COMPONENT U26 component rule.答：這是有關(guān)制造方面的一個(gè)檢查，您沒有相關(guān)設(shè)定，所以可以不檢查。 問： 怎樣導(dǎo)出jop文件？答：應(yīng)該是JOB文件吧？低版本的powerPCB與PADS使用JOB文件。現(xiàn)在只能輸出ASC文件，方法如下STEP：FILE/EXPORT/選擇一個(gè)asc名稱/選擇Select ALL/在Format下選擇合適的版本/在Unit下選Current比較好/點(diǎn)擊OK/完成然后在低版本的powerPCB與PADS產(chǎn)品中Import保存的ASC文件，再保存為JOB文件。 問： 怎樣導(dǎo)入reu文件？答：在ECO與Design 工具盒中都可以進(jìn)行，分別打開ECO與Design 工具盒，點(diǎn)擊右邊第2個(gè)圖標(biāo)就可以。 問： 為什么我在pad stacks中再設(shè)一個(gè)via:1(如附件）和默認(rèn)的standardvi(如附件）在布線時(shí)V選擇1，怎么布線時(shí)按add via不能添加進(jìn)去這是怎么回事，因?yàn)橛袝r(shí)要使用兩種不同的過孔。答：PowerPCB中有多個(gè)VIA時(shí)需要在Design Rule下根據(jù)信號(hào)分別設(shè)置VIA的使用條件，如電源類只能用Standard VIA等等，這樣操作時(shí)就比較方便。詳細(xì)設(shè)置方法在PowerPCB軟件通中有介紹。 問：為什么我把On-line DRC設(shè)置為prevent..移動(dòng)元時(shí)就會(huì)彈出(圖2),而你們教程中也是這樣設(shè)置怎么不會(huì)呢?答：首先這不是錯(cuò)誤,出現(xiàn)的原因是在數(shù)據(jù)中沒有BOARD OUTLINE.您可以設(shè)置一個(gè),但是不使用它作為CAM輸出數(shù)據(jù). 問：我用ctrl+c復(fù)制線時(shí)怎設(shè)置原點(diǎn)進(jìn)行復(fù)制，ctrl+v粘帖時(shí)總是以最下面一點(diǎn)和最左邊那一點(diǎn)為原點(diǎn) 答： 復(fù)制布線時(shí)與上面的MOVE MODE設(shè)置沒有任何關(guān)系,需要在右鍵菜單中選擇,這在PowerPCB軟件通教程中有專門介紹. 問：用(圖4)進(jìn)行修改線時(shí)拉起時(shí)怎總是往左邊拉起(圖5)，不知有什么辦法可以輕易想拉起左就左，右就右。答： 具體條件不明,請(qǐng)檢查一下您的DESIGN GRID,是否太大了. 問： 好不容易拉起右邊但是用(圖6)修改線怎么改怎么下面都會(huì)有一條不能和在一起，而你教程里都會(huì)好好的(圖8)答：這可能還是與您的GRID 設(shè)置有關(guān),不過沒有問題,您可以將不需要的那段線刪除.最重要的是需要找到布線的感覺,每個(gè)軟件都不相同,所以需要多練習(xí)。 問： 尊敬的老師:您好！這個(gè)圖已經(jīng)畫好了，但我只對(duì)（如圖1）一種的完全間距進(jìn)行檢查，怎么錯(cuò)誤就那么多，不知怎么改進(jìn)。請(qǐng)老師指點(diǎn)。這個(gè)圖在附件中請(qǐng)老師幫看一下，如果還有什么問題請(qǐng)指出來，本人在改進(jìn)。謝！！！！！答：請(qǐng)注意您的DRC SETUP窗口下的設(shè)置是錯(cuò)誤的,現(xiàn)在選中的SAME NET是對(duì)相同NET進(jìn)行檢查,應(yīng)該選擇NET TO ALL.而不是SAME NET有關(guān)各項(xiàng)參數(shù)的含義請(qǐng)仔細(xì)閱讀第5部教程. 問： U101元件已建好，但元件框的拐角處不知是否正確，請(qǐng)幫忙CHECK 答：元件框等可以通過修改編輯來完成。問： U102和U103元件沒建完全，在自動(dòng)建元件參數(shù)中有幾個(gè)不明白：如：SOIC--》silk screen欄下spacing from pin與outdent from first pin對(duì)應(yīng)U102和U103元件應(yīng)寫什么數(shù)值，還有這兩個(gè)元件SILK怎么自動(dòng)設(shè)置，以及SILK內(nèi)有個(gè)圓圈怎么才能畫得與該元件參數(shù)一致。 答：Spacing from pin指從PIN到SILK的Y方向的距離,outdent from first pin是第一PIN與SILK端點(diǎn)間的距離.請(qǐng)根據(jù)元件資料自己計(jì)算。
標(biāo)簽： PCB 設(shè)計(jì)問題 集錦
上傳時(shí)間： 2013-10-07
上傳用戶：comer1123
As the performance of many handheld devices approachesthat of laptop computers, design complexity also increases.Chief among them is thermal management—how doyou meet increasing performance demands while keepinga compact and small product cool in the user’s hand?For instance, as battery capacities inevitably increase,charge currents will also increase to maintain or improvetheir charge times. Traditional linear regulator-based batterychargers will not be able to meet the charge currentand effi ciency demands necessary to allow a product torun cool. What is needed is a switching-based chargerthat takes just about the same amount of space as a linearsolution—but without the heat.
上傳時(shí)間： 2013-11-23
上傳用戶：lu2767
What would happen if someone connected 24V to your12V circuits? If the power and ground lines were inadvertentlyreversed, would the circuits survive? Does yourapplication reside in a harsh environment, where the inputsupply can ring very high or even below ground? Evenif these events are unlikely, it only takes one to destroya circuit board.
上傳時(shí)間： 2013-10-26
上傳用戶：jackandlee
數(shù)字信號(hào)處理器dsPIC33F集多通道高精度A/D轉(zhuǎn)換、多通訊模式、看門狗、CMOS Flash技術(shù)等于一體，其內(nèi)部可完成所有數(shù)據(jù)操作，實(shí)現(xiàn)總線不出芯片技術(shù)。將該處理器應(yīng)用于微機(jī)保護(hù)裝置，提出基于dsPIC33F微處理器的微機(jī)保護(hù)裝置的設(shè)計(jì)方案，給出相應(yīng)的接口電路與軟件流程。該設(shè)計(jì)方案結(jié)構(gòu)簡單，性價(jià)比及可靠性高，開發(fā)周期短，具有一定的實(shí)用推廣價(jià)值。所研制的微機(jī)保護(hù)裝置現(xiàn)場運(yùn)行效果良好。 Abstract: The dsPIC33F microprocessor has a plentiful interior resource which contains multi-channel，high precision A/D converters，multi-communication module，watchdog，CMOS Flash technology，and so on.All data manipulations is accomplished interiorly.What is more，it makes the technology that bus does not go beyond the chip comes into practice.The paper put forwards a design scheme based on dsPIC33F microprocessor.The scheme has the advantages of simple structure，high reliability and shortened exploitation cycle.What is more，it has definite practicality and reference.The microcomputer protection device has been put into operation with excellent effects.
上傳時(shí)間： 2013-11-16
上傳用戶：開懷常笑
What is New in C51 Version 8.18[Device Support]Added debug support for the NXP P89LPC9408 in the LPC900 EPM Emulator/Programmer.[New Supported Device]Nuvoton W681308 device.[New Supported Device]NXP P89LPC9201, P89LPC9211, P89LPC922A1, P89LPC9241, P89LPC9251, P89LPC9301, P89LPC931A1, P89LPC9331, P89LPC9341, and P89LPC9351 devices.[New Supported Device]SiLabs C8051F500, C8051F501, C8051F504, C8051F505, C8051F506, C8051F507, C8051F508, C8051F509, C8051F510, and C8051F511 devices.[ULINK2 Support]Corrected potential deadlock on ST uPSD targets.[Device Simulation]Corrected simulation of Infineon XC800 MDU.[Device Simulation]Corrected behaviour of EXFn and TOGn on SiLabs C8051F12x/F13x devices.[Device Simulation]Added simulation for Atmel AT89C51RE2, including simulation of second UART.[Cx51 Compiler]Corrected failed initialization on far addresses when the object is located with _at_. 本資料僅供學(xué)習(xí)評(píng)估之用,請(qǐng)勿用于商業(yè)用途!請(qǐng)?jiān)趯W(xué)習(xí)評(píng)估24小時(shí)內(nèi)刪除.
上傳時(shí)間： 2013-11-01
上傳用戶：panpanpan
Internal Interrupts are used to respond to asynchronous requests from a certain part of themicrocontroller that needs to be serviced. Each peripheral in the TriCore as well as theBus Control Unit, the Debug Unit, the Peripheral Control Processor (PCP) and the CPUitself can generate an Interrupt Request.So What is an external Interrupt?An external Interrupt is something alike as the internal Interrupt. The difference is that anexternal Interrupt request is caused by an external event. Normally this would be a pulseon Port0 or Port1, but it can be even a signal from the input buffer of the SSC, indicatingthat a service is requested.The User’s Manual does not explain this aspect in detail so this ApNote will explain themost common form of an external Interrupt request. This ApNote will show that there is aneasy way to react on a pulse on Port0 or Port1 and to create with this impulse an InterruptService Request. Later in the second part of the document, you can find hints on how todebounce impulses to enable the use of a simple switch as the input device.Note: You will find additional information on how to setup the Interrupt System in theApNote “First steps through the TriCore Interrupt System” (AP3222xx)1. It would gobeyond the scope of this document to explain this here, but you will find selfexplanatoryexamples later on.
標(biāo)簽： Exter easy work with
上傳時(shí)間： 2013-10-27
上傳用戶：zhangyigenius
計(jì)算機(jī)部件要具有通用性，適應(yīng)不同系統(tǒng)與不同用戶的需求，設(shè)計(jì)必須模塊化。計(jì)算機(jī)部件產(chǎn)品(模塊)供應(yīng)出現(xiàn)多元化。模塊之間的聯(lián)接關(guān)系要標(biāo)準(zhǔn)化，使模塊具有通用性。模塊設(shè)計(jì)必須基于一種大多數(shù)廠商認(rèn)可的模塊聯(lián)接關(guān)系，即一種總線標(biāo)準(zhǔn)。總線的標(biāo)準(zhǔn)總線是一類信號(hào)線的集合是模塊間傳輸信息的公共通道，通過它，計(jì)算機(jī)各部件間可進(jìn)行各種數(shù)據(jù)和命令的傳送。為使不同供應(yīng)商的產(chǎn)品間能夠互換，給用戶更多的選擇，總線的技術(shù)規(guī)范要標(biāo)準(zhǔn)化。總線的標(biāo)準(zhǔn)制定要經(jīng)周密考慮，要有嚴(yán)格的規(guī)定。總線標(biāo)準(zhǔn)（技術(shù)規(guī)范）包括以下幾部分：機(jī)械結(jié)構(gòu)規(guī)范：模塊尺寸、總線插頭、總線接插件以及按裝尺寸均有統(tǒng)一規(guī)定。功能規(guī)范：總線每條信號(hào)線（引腳的名稱）、功能以及工作過程要有統(tǒng)一規(guī)定。電氣規(guī)范：總線每條信號(hào)線的有效電平、動(dòng)態(tài)轉(zhuǎn)換時(shí)間、負(fù)載能力等。總線的發(fā)展情況S-100總線：產(chǎn)生于1975年，第一個(gè)標(biāo)準(zhǔn)化總線，為微計(jì)算機(jī)技術(shù)發(fā)展起到了推動(dòng)作用。IBM-PC個(gè)人計(jì)算機(jī)采用總線結(jié)構(gòu)（Industry Standard Architecture, ISA)并成為工業(yè)化的標(biāo)準(zhǔn)。先后出現(xiàn)8位ISA總線、16位ISA總線以及后來兼容廠商推出的EISA（Extended ISA)32位ISA總線。為了適應(yīng)微處理器性能的提高及I/O模塊更高吞吐率的要求，出現(xiàn)了VL-Bus(VESA Local Bus)和PCI(Peripheral Component Interconnect,PCI）總線。適合小型化要求的PCMCIA(Personal Computer Memory Card International Association)總線，用于筆記本計(jì)算機(jī)的功能擴(kuò)展。總線的指標(biāo)計(jì)算機(jī)主機(jī)性能迅速提高,各功能模塊性能也要相應(yīng)提高,這對(duì)總線性能提出更高的要求。總線主要技術(shù)指標(biāo)有幾方面：總線寬度：一次操作可以傳輸?shù)臄?shù)據(jù)位數(shù)，如S100為8位，ISA為16位，EISA為32位，PCI-2可達(dá)64位。總線寬度不會(huì)超過微處理器外部數(shù)據(jù)總線的寬度。總數(shù)工作頻率：總線信號(hào)中有一個(gè)CLK時(shí)鐘，CLK越高每秒鐘傳輸?shù)臄?shù)據(jù)量越大。ISA、EISA為8MHz，PCI為33.3MHz, PCI-2可達(dá)達(dá)66.6MHz。單個(gè)數(shù)據(jù)傳輸周期：不同的傳輸方式，每個(gè)數(shù)據(jù)傳輸所用CLK周期數(shù)不同。ISA要2個(gè)，PCI用1個(gè)CLK周期。這決定總線最高數(shù)據(jù)傳輸率。5. 總線的分類與層次系統(tǒng)總線：是微處理器芯片對(duì)外引線信號(hào)的延伸或映射，是微處理器與片外存儲(chǔ)器及I/0接口傳輸信息的通路。系統(tǒng)總線信號(hào)按功能可分為三類：地址總線（Where）：指出數(shù)據(jù)的來源與去向。地址總線的位數(shù)決定了存儲(chǔ)空間的大小。系統(tǒng)總線：數(shù)據(jù)總線（What）提供模塊間傳輸數(shù)據(jù)的路徑，數(shù)據(jù)總線的位數(shù)決定微處理器結(jié)構(gòu)的復(fù)雜度及總體性能。控制總線（When）：提供系統(tǒng)操作所必需的控制信號(hào)，對(duì)操作過程進(jìn)行控制與定時(shí)。擴(kuò)充總線：亦稱設(shè)備總線，用于系統(tǒng)I/O擴(kuò)充。與系統(tǒng)總線工作頻率不同，經(jīng)接口電路對(duì)系統(tǒng)總統(tǒng)信號(hào)緩沖、變換、隔離，進(jìn)行不同層次的操作（ISA、EISA、MCA)局部總線：擴(kuò)充總線不能滿足高性能設(shè)備（圖形、視頻、網(wǎng)絡(luò)）接口的要求，在系統(tǒng)總線與擴(kuò)充總線之間插入一層總線。由于它經(jīng)橋接器與系統(tǒng)總線直接相連，因此稱之為局部總線（PCI）。
標(biāo)簽： 微型計(jì)算機(jī) 總線
上傳時(shí)間： 2013-11-09
上傳用戶：nshark
The CodeWarrior Development Suite provides access and technical support to amultitude of CodeWarrior products. In this quick start guide, Section 1 explains howto register your CodeWarrior Development Suite. Section 2 explains how to activateand install one of your products. Section 3 describes What you are entitled to withthe purchase of your CodeWarrior Development Suite, and Section 4 discusses theavailable purchase options. Section 5 describes the benefits of maintaining a currenttechnical support contract, and Section 6 tells you how to access support.
標(biāo)簽： CodeWarrior 開發(fā)套件
上傳時(shí)間： 2014-03-02
上傳用戶：784533221
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