<li id="4u6ou"></li> <center id="4u6ou"></center>
SRAM-based FPGAs are non-volatile devices. Upon powerup, They are required to be programmed from an external source. This procedure allows anyone to easily monitor the bit-stream, and clone the device. The problem then becomes how can you effectively protect your intellectual property from others in an architecture where the part is externally programmed?
上傳時間： 2013-11-06
上傳用戶：wl9454
針對嵌入式機器視覺系統(tǒng)向獨立化、智能化發(fā)展的要求，介紹了一種嵌入式視覺系統(tǒng)--智能相機。基于對智能相機體系結構、組成模塊和圖像采集、傳輸和處理技術的分析，對國內外的幾款智能相機進行比較。綜合技術發(fā)展現狀，提出基于FPGA+DSP模式的硬件平臺，并提出智能相機的發(fā)展方向。分析結果表明，該系統(tǒng)設計可以實現脫離PC運行，完成圖像獲取與分析，并作出相應輸出。 Abstract: This paper introduced an embedded vision system-intelligent camera ，which was for embedded machine vision systems to an independent and intelligent development requirements. Intelligent camera architecture， component modules and image acquisition， transmission and processing technology were analyzed. After comparing integrated technology development of several intelligent cameras at home and abroad， the paper proposed the hardware platform based on FPGA+DSP models and made clear direction of development of intelligent cameras. On the analysis of the design， the results indicate that the system can run from the PC independently to complete the image acquisition and analysis and give a corresponding output.
上傳時間： 2013-10-24
上傳用戶：bvdragon
為了在CDMA系統(tǒng)中更好地應用QDPSK數字調制方式，在分析四相相對移相（QDPSK)信號調制解調原理的基礎上，設計了一種QDPSK調制解調電路，它包括串并轉換、差分編碼、四相載波產生和選相、相干解調、差分譯碼和并串轉換電路。在MAX+PLUSⅡ軟件平臺上，進行了編譯和波形仿真。綜合后下載到復雜可編程邏輯器件EPM7128SLC84-15中，測試結果表明，調制電路能正確選相，解調電路輸出數據與QDPSK調制輸入數據完全一致，達到了預期的設計要求。 Abstract: In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase，and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.
上傳時間： 2014-01-13
上傳用戶：qoovoop
波長信號的解調是實現光纖光柵傳感網絡的關鍵，基于現有的光纖光柵傳感器解調方法，提出一種基于FPGA的雙匹配光纖光柵解調方法，此系統(tǒng)是一種高速率、高精度、低成本的解調系統(tǒng)，并且通過引入雙匹配光柵有效地克服了雙值問題同時擴大了檢測范圍。分析了光纖光柵的測溫原理并給出了該方案軟硬件設計，綜合考慮系統(tǒng)的解調精度和FPGA的處理速度給出了基于拉格朗日的曲線擬合算法。 Abstract: Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network， based on several existing methods of fiber grating sensor demodulation inadequate， a two-match fiber grating demodulation method was presented. This system is a high-speed， high precision， low-cost demodulation system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA，this paper gives the curve fitting algorithm based on Lagrange.
標簽： FPGA 光纖光柵 解調系統(tǒng)
上傳時間： 2014-07-24
上傳用戶：caiguoqing
a8259 可編程中斷控制 altera提供 The a8259 is designed to simplify the implementation of the interrupt interface in 8088 and 8086 based microcomputer systems. The device is known as a programmable interrupt controller. The a8259 receives and prioritizes up to 8 interrupts, and in the cascade mode, this can be expanded up to 64 interrupts. An asynchronous reset and a clock input have been added to improve operation and reliability.
上傳時間： 2014-11-29
上傳用戶：zhyiroy
傳統(tǒng)的基于位置信息的服務（LBS）的隱私保護需要LBS提供者（簡稱LSP）與用戶之間通過第三方作為中介來進行信息交換，但這種模式極易遭到攻擊者攻擊。為此提出一種基于K-匿名機制的隱形空間算法KABSCA（k-anonymity based spatial cloaking algorithm ），通過移動設備獨立建立一個分布式網絡直接與LSP通訊進而避免了第三方的安全威脅。仿真實驗顯示:使用這種算法，用戶可以享受到高質量的信息服務以及高度的隱私保護。
上傳時間： 2013-11-06
上傳用戶：540750247
Modbus詳解(全書+PDF)
標簽： Modbus Controller Based
上傳時間： 2013-10-09
上傳用戶：lijinchuan
The Tri-Mode Ethernet MAC (TEMAC) UltraController-II module is a minimal footprint,embedded network processing engine based on the PowerPC™ 405 (PPC405) processor coreand the TEMAC core embedded within a Virtex™-4 FX Platform FPGA. The TEMACUltraController-II module connects to an external PHY through Gigabit Media IndependentInterface (GMII) and Management Data Input/Output (MDIO) interfaces and supports tri-mode(10/100/1000 Mb/s) Ethernet. Software running from the processor cache reads and writesthrough an On-Chip Memory (OCM) interface to two FIFOs that act as buffers between thedifferent clock domains of the PPC405 OCM and the TEMAC.
上傳時間： 2013-10-26
上傳用戶：yuzsu
針對飛行模擬器座艙數據采集的復雜性，設計了一種基于以太網分布式的數據采集控制系統(tǒng)，該系統(tǒng)是RCM5700微處理器模塊上的以太網應用。在系統(tǒng)的基礎上具體討論了PoE技術的應用，在傳輸數據的網線上同時提供電流，提出并實現了一種包括輔助電源在內的完整可靠的PoE供電方案。設計采用美國國家半導體的LM5073和LM5576并根據不同的負載情況，進行穩(wěn)定可靠的電壓轉換，以滿足數據采集電路的要求。實驗結果表明：該設計穩(wěn)定可靠，滿足低于13 W的采集節(jié)點供電要求，提高了模擬器信號采集系統(tǒng)的通用性和標準化程度，避免了以往數據采集節(jié)點單獨繁瑣的電源設計。 Abstract: Aiming at the complexity of large avion simulation and controlling，the simulator cabin distribute data collecting and control system was designed. This system is the application of RCM5700 on Ethernet. Based on this system，PoE technique that makes Ethernet can also provide power were expounded with emphasis and included FAUX design the PoE resolution was realized. To achieve the requirement of this system，LM5073 and LM5576 were used to DC-DC switch. From the data of experiment，the design filled the requirement of power-need of node whose power was lower than 13W. The application of the technique can advance the degree of simulation data collections currency and standardization and avoid designing additional power system.
標簽： 以太網 分布式 數據采集 控制系統(tǒng)
上傳時間： 2013-11-09
上傳用戶：xyipie
在現代通信系統(tǒng)中，電話語音的頻帶被限制在300 Hz～4 kHz的范圍內，帶來了語音可懂度和自然度的降低。為了在不增加額外成本的前提下提高語音的可懂度和自然度，進行了電話語音頻帶擴展的研究。提出了一種改進的基于碼本映射的語音帶寬擴展算法：在碼本映射的過程中，使用加權系數來得到映射碼本。客觀測試結果表明，用此算法得到的寬帶語音的譜失真度比用一般的碼本映射降低至少2%。主觀測試結果表明，用此算法得到的寬帶語音具有更好的可懂度和自然度。 Abstract: In modern communication systems， the bandwidth of telephone speech is limited from 300Hz to 4 kHz， which reduces the intelligibility and naturalness of speech. Telephone speech bandwidth extension is researched to get wideband speech and to improve its intelligibility and naturalness， without increasing extra costs. This paper put forward an improved algorithm of speech bandwidth extension based on codebook mapping. In the process of codebook mapping， weighted coefficients were used to get mapping codebook. Objective tests show that spectral distortion of wideband speech obtained by this algorithm reduces at least 2%， comparing to conditional codebook mapping. Subjective tests show that the wideband speech obtained by this algorithm has better intelligibility and naturalness.
上傳時間： 2014-12-29
上傳用戶：15501536189
<rt id="844w4"></rt>