Abstract: The number of uses for microelectromechanical systems (MEMS) is growing—they allow us todo jobs once considered impossible. This tutorial explains the applications for MEMS and the increasingneed to provide precision control and drivers for these DEVices. Design and manufacturing considerationsare also discussed.
標(biāo)簽: MEMS 微機(jī)電系統(tǒng) 控制驅(qū)動
上傳時間: 2013-11-12
上傳用戶:paladin
多遠(yuǎn)程二極管溫度傳感器-Design Considerations for pc thermal management Multiple RDTS (remote diode temperature sensing) provides the most accurate method of sensing an IC’s junction temperature. It overcomes thermal gradient and placement issues encountered when trying to place external sensors. PCB component count decreases when using a device that provides multiple inputs.Better temperature sensing improves product performance and reliability. Disk drive data integrity suffers at elevated temperatures. IBM published an article stating that a 5°C rise in operating temperature causes a 15% increase in the drive’s failure rate. The overall performance of a system can be improved by providing a more accurate temperature measurement of the most critical DEVices allowing them to run just a few degrees hotter.The LM83 directly senses its own temperature and the temperature of three external PN junctions. One is dedicated to the CPU of choice, the other two go to other parts of your system that need thermal monitoring such as the disk drive or graphics chip. The SMBus-compatible LM83 supports SMBus timeout and logic levels. The LM83 has two interrupt outputs; one for user-programmable limits and WATCHDOG capability (INT), the other is a Critical Temperature Alarm output (T_CRIT_A) for system power supply shutdown.
標(biāo)簽: Considerat Design 遠(yuǎn)程 二極管
上傳時間: 2014-12-21
上傳用戶:ljd123456
Abstract: Communication with 1-Wire slave DEVices requires a 1-Wire master. There are numerous ways to build a 1-Wire master (see reference design 4206, "Choosing the Right 1-Wire Master for Embedded Applications"). Thisdocument describes the DS1WM, a synthesizable 1-Wire master that can be implemented in an application-specificintegrated circuit (ASIC) or field-programmable gate array (FPGA).
上傳時間: 2014-12-22
上傳用戶:xanxuan
嵌入式系統(tǒng)是一種應(yīng)用范圍非常廣泛的系統(tǒng)。可以說除了桌面計算機(jī)和服務(wù)器外所有計算設(shè)備都屬于嵌入式系統(tǒng),例如從便攜式音樂播放器到航天飛機(jī)上的實(shí)時系統(tǒng)控制都屬于嵌入式系統(tǒng)。 大多數(shù)商用的嵌入式系統(tǒng)都設(shè)計成專用任務(wù)的低成本的產(chǎn)品。大多數(shù)的嵌入式系統(tǒng)都具有實(shí)時性的要求。有些功能需要非常快的主頻,但其他大多數(shù)功能并不需要高速的處理能力。這些系統(tǒng)通過特定的器件和軟件來滿足實(shí)時性的要求。 簡單地通過速度和成本來定義嵌入式系統(tǒng)是困難的,但對于大批量的產(chǎn)品而言,成本常常對系統(tǒng)設(shè)計起決定作用。通常,一個嵌入式系統(tǒng)的很多部分相對系統(tǒng)主要功能來說需要較低的性能,因此嵌入式系統(tǒng)和通用PC相比,能夠使用一個滿足輔助功能的合適的CPU,從而簡化了系統(tǒng)設(shè)計,降低了成本。例如,數(shù)字電視的機(jī)頂盒需要處理每秒以百萬兆位計的連續(xù)數(shù)據(jù),但這些數(shù)據(jù)處理大部分是由定制的硬件來實(shí)現(xiàn)的,如解析、管理和編解碼多個頻道的數(shù)字影像。 對于大批量生產(chǎn)的嵌入式系統(tǒng),如便攜式音樂播放器或手機(jī)等,降低成本就成為最主要的問題。這些系統(tǒng)通常只具有幾個芯片:一個高度集成的CPU,一個定制的芯片用于控制其他所有的功能,還有一個存儲芯片。在這種設(shè)計中,每部分都設(shè)計成使用最小的系統(tǒng)功耗。 對于小批量的嵌入式應(yīng)用,為了降低開發(fā)成本,常常使用PC體系結(jié)構(gòu),通過限制程序的執(zhí)行時間或用一個實(shí)時操作系統(tǒng)來替換原先的操作系統(tǒng)。在這種情況下,可以使用一個或多個高性能的CPU來替換特殊用途的硬件。 嵌入式系統(tǒng)的軟件通常運(yùn)行在有限的硬件資源上:沒有硬盤、操作系統(tǒng)、鍵盤或屏幕。軟件一般都沒有文件系統(tǒng),如果有的話,也會采用Flash驅(qū)動器。如果有人機(jī)交互接口的話,也是一個小鍵盤或液晶顯示器。硬件是計算機(jī)的物理部分,和存儲在硬件中的計算機(jī)軟件程序和數(shù)據(jù)區(qū)分開來。 嵌入到機(jī)械中的嵌入式系統(tǒng)需要長期無故障連續(xù)運(yùn)行,因此它的軟件需要比PC中的軟件更加仔細(xì)地開發(fā)和更加嚴(yán)格地測試。 那么,到底什么是嵌入式系統(tǒng)呢? 根據(jù)IEEE(國際電氣和電子工程師協(xié)會)的定義,嵌入式系統(tǒng)是“控制、監(jiān)視或者輔助設(shè)備、機(jī)器和車間運(yùn)行的裝置”(原文為DEVices used to control,monitor,or assist the operation of equipment,machinery or plants)。這主要是從應(yīng)用上加以定義的,從中可以看出嵌入式系統(tǒng)是軟件和硬件的綜合體,還可以涵蓋機(jī)械等附屬裝置。 目前國內(nèi)一個普遍被認(rèn)同的定義是:以應(yīng)用為中心、以計算機(jī)技術(shù)為基礎(chǔ),軟件 硬件可裁剪,適應(yīng)應(yīng)用系統(tǒng)對功能、可靠性、成本、體積、功耗嚴(yán)格要求的專用計算機(jī)系統(tǒng)。 可以這樣認(rèn)為,嵌入式系統(tǒng)是一種專用的計算機(jī)系統(tǒng),作為裝置或設(shè)備的一部分。通常,嵌入式系統(tǒng)是一個控制程序存儲在ROM中的嵌入式處理器控制板。事實(shí)上,所有帶有數(shù)字接口的設(shè)備,如手表、微波爐、錄像機(jī)、汽車等,都使用嵌入式系統(tǒng),有些嵌入式系統(tǒng)還包含操作系統(tǒng),但大多數(shù)嵌入式系統(tǒng)都是由單個程序?qū)崿F(xiàn)整個控制邏輯。 本書是按照人事部、信息產(chǎn)業(yè)部全國計算機(jī)技術(shù)與軟件專業(yè)技術(shù)資格(水平)考試要求編寫,內(nèi)容緊扣《嵌入式系統(tǒng)設(shè)計考試大鋼》。全書共六章,分別對嵌入式系統(tǒng)基礎(chǔ)知識、嵌入式微處理器與接口設(shè)計、嵌入式軟件與操作系統(tǒng)、嵌入式軟件程序設(shè)計、嵌入式系統(tǒng)設(shè)計與維護(hù)等知識進(jìn)行了詳細(xì)的講解。最后介紹了一個典型的嵌入式系統(tǒng)設(shè)計案例。 本書內(nèi)容豐富,結(jié)構(gòu)合理,概念清晰。既可作為全國計算機(jī)技術(shù)與軟件專業(yè)技術(shù)資格(水平)考試中嵌入式系統(tǒng)設(shè)計師級別的考試用書,供有關(guān)考生學(xué)習(xí)使用,也可作為本科生嵌入式系統(tǒng)相關(guān)課程教材或培訓(xùn)書使用。
標(biāo)簽: 嵌入式 系統(tǒng)設(shè)計師 教程
上傳時間: 2013-10-29
上傳用戶:dongqiangqiang
Abstract: The 1-Wire product family includes numerous DEVices that can be easily evaluated using a Windows®-based
上傳時間: 2013-10-12
上傳用戶:fudong911
The C8051F020/1/2/3 DEVices are fully integrated mixed-signal System-on-a-Chip MCUs with 64 digital I/O pins (C8051F020/2) or 32 digital I/O pins (C8051F021/3). Highlighted features are listed below; refer to Table 1.1 for specific product feature selection.
標(biāo)簽: C8051F020 數(shù)據(jù)手冊
上傳時間: 2013-11-08
上傳用戶:lwq11
The NCV7356 is a physical layer device for a single wire data linkcapable of operating with various Carrier Sense Multiple Accesswith Collision Resolution (CSMA/CR) protocols such as the BoschController Area Network (CAN) version 2.0. This serial data linknetwork is intended for use in applications where high data rate is notrequired and a lower data rate can achieve cost reductions in both thephysical media components and in the microprocessor and/ordedicated logic DEVices which use the network.The network shall be able to operate in either the normal data ratemode or a high-speed data download mode for assembly line andservice data transfer operations. The high-speed mode is onlyintended to be operational when the bus is attached to an off-boardservice node. This node shall provide temporary bus electrical loadswhich facilitate higher speed operation. Such temporary loads shouldbe removed when not performing download operations.The bit rate for normal communications is typically 33 kbit/s, forhigh-speed transmissions like described above a typical bit rate of83 kbit/s is recommended. The NCV7356 features undervoltagelockout, timeout for faulty blocked input signals, output blankingtime in case of bus ringing and a very low sleep mode current.
上傳時間: 2013-10-24
上傳用戶:s藍(lán)莓汁
The LPC2292/2294 microcontrollers are based on a 16/32-bit ARM7TDMI-S CPU with real-time emulation and embedded trace support, together with 256 kB of embedded high-speed flash memory. A 128-bit wide memory interface and a unique accelerator architecture enable 32-bit code execution at the maximum clock rate. For critical code size applications, the alternative 16-bit Thumb mode reduces code by more than 30 pct with minimal performance penalty. With their 144-pin package, low power consumption, various 32-bit timers, 8-channel 10-bit ADC, 2/4 (LPC2294) advanced CAN channels, PWM channels and up to nine external interrupt pins these microcontrollers are particularly suitable for automotive and industrial control applications as well as medical systems and fault-tolerant maintenance buses. The number of available fast GPIOs ranges from 76 (with external memory) through 112 (single-chip). With a wide range of additional serial communications interfaces, they are also suited for communication gateways and protocol converters as well as many other general-purpose applications. Remark: Throughout the data sheet, the term LPC2292/2294 will apply to DEVices with and without the /00 or /01 suffix. The suffixes /00 and /01 will be used to differentiate from other DEVices only when necessary.
標(biāo)簽: lpc datasheet 2292 2294
上傳時間: 2014-12-30
上傳用戶:aysyzxzm
Keil C51 V8 專業(yè)開發(fā)工具(PK51) PK51是為8051系列單片機(jī)所設(shè)計的開發(fā)工具,支持所有8051系列衍生產(chǎn)品,,支持帶擴(kuò)展存儲器和擴(kuò)展指令集(例如Dallas390/5240/400,Philips 51MX,Analog DEVices MicroConverters)的新設(shè)備,以及支持很多公司的一流的設(shè)備和IP內(nèi)核,比如Analog DEVices, Atmel, Cypress Semiconductor, Dallas Semiconductor, Goal, Hynix, Infineon, Intel, NXP(founded by Philips), OKI, Silicon Labs,SMSC, STMicroeleectronics,Synopsis, TDK, Temic, Texas Instruments,Winbond等。 通過PK51專業(yè)級開發(fā)工具,可以輕松地了解8051的On-chip peripherals與及其它關(guān)鍵特性。 The PK51專業(yè)級開發(fā)工具包括… l μVision Ø 集成開發(fā)環(huán)境 Ø 調(diào)試器 Ø 軟件模擬器 l Keil 8051擴(kuò)展編譯工具 Ø AX51宏匯編程序 Ø ANSI C編譯工具 Ø LX51 連接器 Ø OHX51 Object-HEX 轉(zhuǎn)換器 l Keil 8051編譯工具 Ø A51宏匯編程序 Ø C51 ANSI C編譯工具 Ø BL51 代碼庫連接器 Ø OHX51 Object-HEX 轉(zhuǎn)換器 Ø OC51 集合目標(biāo)轉(zhuǎn)換器 l 目標(biāo)調(diào)試器 Ø FlashMON51 目標(biāo)監(jiān)控器 Ø MON51目標(biāo)監(jiān)控器 Ø MON390 (Dallas 390)目標(biāo)監(jiān)控器 Ø MONADI (Analog DEVices 812)目標(biāo)監(jiān)控器 Ø ISD51 在系統(tǒng)調(diào)試 l RTX51微實(shí)時內(nèi)核 你應(yīng)該考慮PK51開發(fā)工具包,如果你… l 需要用8051系列單片機(jī)來開發(fā) l 需要開發(fā) Dallas 390 或者 Philips 51MX代碼 l 需要用C編寫代碼 l 需要一個軟件模擬器或是沒有硬件仿真器 l 需要在單芯片上基于小實(shí)時內(nèi)核創(chuàng)建復(fù)雜的應(yīng)用
上傳時間: 2013-10-30
上傳用戶:yy_cn
We offer a broad line of high performance low dropout (LDO) linear regulators with fasttransient response, excellent line and load regulation, and very wide input voltage rangefrom 0.9V to 100V. Output currents range from 20mA to 10A, with positive, negative andmultiple output versions available. Many DEVices offer output voltage operation <0.8V andsome feature operation as low as 0V, even with a single supply. Most are stable with ceramicoutput capacitors. LDO regulators can be applied in virtually any application.
上傳時間: 2013-11-15
上傳用戶:努力努力再努力
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