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Second-Level

  • UHF读写器设计中的FM0解码技术

       针对UHF读写器设计中,在符合EPC Gen2标准的情况下,对标签返回的高速数据进行正确解码以达到正确读取标签的要求,提出了一种新的在ARM平台下采用边沿捕获统计定时器数判断数据的方法,并对FM0编码进行解码。与传统的使用定时器定时采样高低电平的FM0解码方法相比,该解码方法可以减少定时器定时误差累积的影响;可以将捕获定时器数中断与数据判断解码相对分隔开,使得中断对解码影响很小,实现捕获与解码的同步。通过实验表明,这种方法提高了解码的效率,在160 Kb/s的接收速度下,读取一张标签的时间约为30次/s。 Abstract:  Aiming at the requirement of receiving correctly decoded data from the tag under high-speed communication which complied with EPC Gen2 standard in the design of UHF interrogator, the article introduced a new technology for FM0 decoding which counted the timer counter to judge data by using the edge interval of signal capture based on the ARM7 platform. Compared with the traditional FM0 decoding method which used the timer timed to sample the high and low level, the method could reduce the accumulation of timing error and could relatively separate capture timer interrupt and the data judgment for decoding, so that the disruption effect on the decoding was small and realizd synchronization of capture and decoding. Testing result shows that the method improves the efficiency of decoding, at 160 Kb/s receiving speed, the time of the interrogator to read a tag is about 30 times/s.

    标签: UHF FM0 读写器 解码技术

    上传时间: 2013-11-10

    上传用户:liufei

  • ARM手机MID平板方案详解

    ARM核心是主控SOC中的重要部分,系统的日常应用都由ARM核心来完成,因此ARM核心的效能很大程度上跟用户体验有关。ARM公司一般用DMIPS/MHz来标称ARM核心的性能。DMIPS是Dhrystone Million Instructions executed Per Second的缩写,反映核心的整数计算能力。但Dhrystone算法代码本身比较叫,可以完全放到Cache中执行,因此反映的只是核心能力,并不能反映缓存、内存I/O性能。

    标签: ARM MID 手机 平板

    上传时间: 2013-10-16

    上传用户:devin_zhong

  • LPC1850 Cortex-M3内核微控制器数据手册

    The LPC1850/30/20/10 are ARM Cortex-M3 based microcontrollers for embeddedapplications. The ARM Cortex-M3 is a next generation core that offers systemenhancements such as low power consumption, enhanced debug features, and a highlevel of support block integration.The LPC1850/30/20/10 operate at CPU frequencies of up to 150 MHz. The ARMCortex-M3 CPU incorporates a 3-stage pipeline and uses a Harvard architecture withseparate local instruction and data buses as well as a third bus for peripherals. The ARMCortex-M3 CPU also includes an internal prefetch unit that supports speculativebranching.The LPC1850/30/20/10 include up to 200 kB of on-chip SRAM data memory, a quad SPIFlash Interface (SPIFI), a State Configuration Timer (SCT) subsystem, two High-speedUSB controllers, Ethernet, LCD, an external memory controller, and multiple digital andanalog peripherals.

    标签: Cortex-M 1850 LPC 内核微控制器

    上传时间: 2014-12-31

    上传用户:zhuoying119

  • LPC4300系列ARM双核微控制器产品数据手册

    The LPC4350/30/20/10 are ARM Cortex-M4 based microcontrollers for embeddedapplications. The ARM Cortex-M4 is a next generation core that offers systemenhancements such as low power consumption, enhanced debug features, and a highlevel of support block integration.The LPC4350/30/20/10 operate at CPU frequencies of up to 150 MHz. The ARMCortex-M4 CPU incorporates a 3-stage pipeline, uses a Harvard architecture withseparate local instruction and data buses as well as a third bus for peripherals, andincludes an internal prefetch unit that supports speculative branching. The ARMCortex-M4 supports single-cycle digital signal processing and SIMD instructions. Ahardware floating-point processor is integrated in the core.The LPC4350/30/20/10 include an ARM Cortex-M0 coprocessor, up to 264 kB of datamemory, advanced configurable peripherals such as the State Configurable Timer (SCT)and the Serial General Purpose I/O (SGPIO) interface, two High-speed USB controllers,Ethernet, LCD, an external memory controller, and multiple digital and analog peripherals

    标签: 4300 LPC ARM 双核微控制器

    上传时间: 2013-10-28

    上传用户:15501536189

  • 101-200晶体管电路集

    This is the second half of our Transistor Circuits e-book. It contains a further 100 circuits, with many of them containing one or more Integrated Circuits (ICs).It's amazing what you can do with transistors but when Integrated Circuits came along, the whole field of electronics exploded.

    标签: 101 200 晶体管 电路

    上传时间: 2013-11-08

    上传用户:603100257

  • 基于(英蓓特)STM32V100的串口程序

    This example provides a description of how  to use the USART with hardware flowcontrol and communicate with the Hyperterminal.First, the USART2 sends the TxBuffer to the hyperterminal and still waiting fora string from the hyperterminal that you must enter which must end by '\r'character (keypad ENTER button). Each byte received is retransmitted to theHyperterminal. The string that you have entered is stored in the RxBuffer array. The receivebuffer have a RxBufferSize bytes as maximum. The USART2 is configured as follow:    - BaudRate = 115200 baud      - Word Length = 8 Bits    - One Stop Bit    - No parity    - Hardware flow control enabled (RTS and CTS signals)    - Receive and transmit enabled    - USART Clock disabled    - USART CPOL: Clock is active low    - USART CPHA: Data is captured on the second edge     - USART LastBit: The clock pulse of the last data bit is not output to                      the SCLK pin

    标签: V100 STM 100 32V

    上传时间: 2013-10-31

    上传用户:yy_cn

  • SMT常用术语之中英文对比

      AI :Auto-Insertion 自动插件   AQL :acceptable quality level 允收水准   ATE :automatic test equipment 自动测试   ATM :atmosphere 气压   BGA :ball grid array 球形矩阵

    标签: SMT 术语 中英文 对比

    上传时间: 2013-11-20

    上传用户:haoxiyizhong

  • Xilinx UltraScale:新一代架构满足您的新一代架构需求(EN)

      中文版详情浏览:http://www.elecfans.com/emb/fpga/20130715324029.html   Xilinx UltraScale:The Next-Generation Architecture for Your Next-Generation Architecture    The Xilinx® UltraScale™ architecture delivers unprecedented levels of integration and capability with ASIC-class system- level performance for the most demanding applications.   The UltraScale architecture is the industr y's f irst application of leading-edge ASIC architectural enhancements in an All Programmable architecture that scales from 20 nm planar through 16 nm FinFET technologies and beyond, in addition to scaling from monolithic through 3D ICs. Through analytical co-optimization with the X ilinx V ivado® Design Suite, the UltraScale architecture provides massive routing capacity while intelligently resolving typical bottlenecks in ways never before possible. This design synergy achieves greater than 90% utilization with no performance degradation.   Some of the UltraScale architecture breakthroughs include:   • Strategic placement (virtually anywhere on the die) of ASIC-like system clocks, reducing clock skew by up to 50%    • Latency-producing pipelining is virtually unnecessary in systems with massively parallel bus architecture, increasing system speed and capability   • Potential timing-closure problems and interconnect bottlenecks are eliminated, even in systems requiring 90% or more resource utilization   • 3D IC integration makes it possible to build larger devices one process generation ahead of the current industr y standard    • Greatly increased system performance, including multi-gigabit serial transceivers, I/O, and memor y bandwidth is available within even smaller system power budgets   • Greatly enhanced DSP and packet handling   The Xilinx UltraScale architecture opens up whole new dimensions for designers of ultra-high-capacity solutions.

    标签: UltraScale Xilinx 架构

    上传时间: 2013-11-21

    上传用户:wxqman

  • PCB Design Considerations and Guidelines for 0.4mm and 0.5mm WLPs

    Abstract: Using a wafer-level package (WLP) can reduce the overall size and cost of your solution.However when using a WLP IC, the printed circuit board (PCB) layout can become more complex and, ifnot carefully planned, result in an unreliable design. This article presents some PCB designconsiderations and general recommendations for choosing a 0.4mm- or 0.5mm-pitch WLP for yourapplication.

    标签: Considerations Guidelines and Design

    上传时间: 2013-11-09

    上传用户:ls530720646

  • Verilog_HDL的基本语法详解(夏宇闻版)

            Verilog_HDL的基本语法详解(夏宇闻版):Verilog HDL是一种用于数字逻辑电路设计的语言。用Verilog HDL描述的电路设计就是该电路的Verilog HDL模型。Verilog HDL既是一种行为描述的语言也是一种结构描述的语言。这也就是说,既可以用电路的功能描述也可以用元器件和它们之间的连接来建立所设计电路的Verilog HDL模型。Verilog模型可以是实际电路的不同级别的抽象。这些抽象的级别和它们对应的模型类型共有以下五种:   系统级(system):用高级语言结构实现设计模块的外部性能的模型。   算法级(algorithm):用高级语言结构实现设计算法的模型。   RTL级(Register Transfer Level):描述数据在寄存器之间流动和如何处理这些数据的模型。   门级(gate-level):描述逻辑门以及逻辑门之间的连接的模型。   开关级(switch-level):描述器件中三极管和储存节点以及它们之间连接的模型。   一个复杂电路系统的完整Verilog HDL模型是由若干个Verilog HDL模块构成的,每一个模块又可以由若干个子模块构成。其中有些模块需要综合成具体电路,而有些模块只是与用户所设计的模块交互的现存电路或激励信号源。利用Verilog HDL语言结构所提供的这种功能就可以构造一个模块间的清晰层次结构来描述极其复杂的大型设计,并对所作设计的逻辑电路进行严格的验证。   Verilog HDL行为描述语言作为一种结构化和过程性的语言,其语法结构非常适合于算法级和RTL级的模型设计。这种行为描述语言具有以下功能:   · 可描述顺序执行或并行执行的程序结构。   · 用延迟表达式或事件表达式来明确地控制过程的启动时间。   · 通过命名的事件来触发其它过程里的激活行为或停止行为。   · 提供了条件、if-else、case、循环程序结构。   · 提供了可带参数且非零延续时间的任务(task)程序结构。   · 提供了可定义新的操作符的函数结构(function)。   · 提供了用于建立表达式的算术运算符、逻辑运算符、位运算符。   · Verilog HDL语言作为一种结构化的语言也非常适合于门级和开关级的模型设计。因其结构化的特点又使它具有以下功能:   - 提供了完整的一套组合型原语(primitive);   - 提供了双向通路和电阻器件的原语;   - 可建立MOS器件的电荷分享和电荷衰减动态模型。   Verilog HDL的构造性语句可以精确地建立信号的模型。这是因为在Verilog HDL中,提供了延迟和输出强度的原语来建立精确程度很高的信号模型。信号值可以有不同的的强度,可以通过设定宽范围的模糊值来降低不确定条件的影响。   Verilog HDL作为一种高级的硬件描述编程语言,有着类似C语言的风格。其中有许多语句如:if语句、case语句等和C语言中的对应语句十分相似。如果读者已经掌握C语言编程的基础,那么学习Verilog HDL并不困难,我们只要对Verilog HDL某些语句的特殊方面着重理解,并加强上机练习就能很好地掌握它,利用它的强大功能来设计复杂的数字逻辑电路。下面我们将对Verilog HDL中的基本语法逐一加以介绍。

    标签: Verilog_HDL

    上传时间: 2014-12-04

    上传用户:cppersonal