Handheld electronic devices play a key role in our everydaylives. Because dependability is paramount, handhelds arecarefully engineered with lightweight power sources forreliable use under normal conditions. But no amount ofcareful engineering can prevent the mistreatment theywill undergo at the hands of humans. For example, whathappens when a factory worker drops a bar code scanner,causing the battery to pop out? Such events areelectronically unpredictable, and important data storedin volatile memory would be lost without some form ofsafety net—namely a short-term power holdup systemthat stores suffi cient energy to supply standby power untilthe battery can be replaced or the data can be stored inpermanent memory.
上传时间： 2013-11-05
上传用户：coeus
SPMC75低功耗操作:本应用例介绍如何设置使SPMC75F2413A进入节电模式。1.2 模式简介SPMC75F2413A有标准模式和两种节电模式（等待模式和就绪模式），相应功能如下： 标准模式（normal）芯片在标准模式下运行耗电最大，所有的外设都可用。 等待模式（Wait）等待模式下，只有CPU掉电停止工作以降低功耗。其它外设保持着先前的状态并且功能可用。一旦唤醒，CPU将继续工作，执行接下去的指令。 就绪模式（Standby）就绪模式下所有的模块都变为无效，此时功耗达到最小。唤醒后，CPU复位并回到标准运行模式。其它外设可以通过软件分别设置关闭。就绪模式下所有功能都会关闭，只有系统时钟仍在工作。如果按键唤醒功能为有效，这两种模式都可以通过按键唤醒。具体唤醒源的分类及唤醒功能的介绍请参考《SPMC75F2413A编程指南》。【注意】如果MCP定时器3或定时器4已经处于PWM输出模式时，芯片不会进入等待或就绪模式。同样在仿真模式下也无法进入等待或就绪模式。
上传时间： 2013-11-20
上传用户：ming52900
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.
标签： Demonstration 3200 USB for
上传时间： 2014-02-27
上传用户：zhangzhenyu
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.
上传时间： 2013-10-24
上传用户：s蓝莓汁
Finite state machines are widely used in digital circuit designs. Generally, when designing a state machine using an HDL, the synthesis tools will optimize away all states that cannot be reached and generate a highly optimized circuit. Sometimes, however, the optimization is not acceptable. For example, if the circuit powers up in an invalid state, or the circuit is in an extreme working environment and a glitch sends it into an undesired state, the circuit may never get back to its normal operating condition.
标签： Creating Machines Mentor State
上传时间： 2013-11-02
上传用户：xauthu
keeloq滚动码解码大全，包含SIMPLE,normal,SECRET等各种加密方式的解码源代码。
上传时间： 2015-05-04
上传用户：tuilp1a
Frequency Scale Conversion From f To f Scale frq2mel mel2frq mel The mel scale is based on the human perception of sinewave pitch. frq2erb erb2frq erb The erb scale is based on the equivalent rectangular bandwidths of the human ear. frq2midi midi2frq midi The midi standard specifies a numbering of semitones with middle C being 60. They can use the normal equal tempered scale or else the pythagorean scale of just intonation. They will in addition output note names in a character format.
标签： Scale Conversion Frequency mel
上传时间： 2015-06-07
上传用户：
一种基于二维链表的稀疏矩阵模半板类设计 A template Class of sparse matrix. Key technology: bin,2-m linked matrix. constructors: 1.normal constuctor 2.copy constuctor. 3.assignment constructor. Basic operator: 1. addition(sub) of two matrix 2. inverse of a matrix. 3. multiply of two matrix. etc.
标签： matrix technology template linked
上传时间： 2013-12-13
上传用户：lwwhust
常用的数学统计算法，希望大家喜欢 Calculate the approximation of the standard normal distribution
标签： 计算
上传时间： 2014-01-08
上传用户：baiom
在通信或其他仿真的时候，常需要产生数学上的normal分布，此代码就是在c语言下实现。
上传时间： 2015-09-19
上传用户：1966640071
