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.
為了在CDMA系統中更好地應用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.
The LogiCORE™ GTP Wizard automates the task of creating HDL wrappers to configure the high-speed serial GTP transceivers in Virtex™-5 LXT and SXT devices. The menu-driven interface allows one or more GTP transceivers to be configured using pre-definedtemplates for popular industry standards, or from scratch, to support a wide variety of custom protocols.The Wizard produces a wrapper, an example design, and a testbench for rapid integration and verification of the serial interface with your custom function
Features• Creates customized HDL wrappers to configureVirtex-5 RocketIO™ GTP transceivers• Users can configure Virtex-5 GTP transceivers toconform to industry standard protocols usingpredefined templates, or tailor the templates forcustom protocols• Included protocol templates provide support for thefollowing specifications: Aurora, CPRI, FibreChannel 1x, Gigabit Ethernet, HD-SDI, OBSAI,OC3, OC12, OC48, PCI Express® (PCIe®), SATA,SATA II, and XAUI• Automatically configures analog settings• Each custom wrapper includes example design, testbench; and both implementation and simulation scripts
本文利用Verilog HDL 語言自頂向下的設計方法設計多功能數字鐘，突出了其作為硬件描述語言的良好的可讀性、可移植性和易理解等優點，并通過Altera QuartusⅡ 4.1 和ModelSim SE 6.0 完成綜合、仿真。此程序通過下載到FPGA 芯片后，可應用于實際的數字鐘顯示中。
關鍵詞：Verilog HDL；硬件描述語言；FPGA
Abstract: In this paper, the process of designing multifunctional digital clock by the Verilog HDL top-down design method is presented, which has shown the readability, portability and easily understanding of Verilog HDL as a hard description language. Circuit synthesis and simulation are performed by Altera QuartusⅡ 4.1 and ModelSim SE 6.0. The program can be used in the truly digital clock display by downloading to the FPGA chip.
Keywords: Verilog HDL；hardware description language；FPGA
The power of programmability gives industrial automation designers a highly efficient， cost-effective alternative to traditional motor control units （MCUs）。 The parallel-processing power， fast computational speeds， and connectivity versatility of Xilinx® FPGAs can accelerate the implementation of advanced motor control algorithms such as Field Oriented Control （FOC）。
Additionally， Xilinx devices lower costs with greater on-chip integration of system components and shorten latencies with high-performance digital signal processing （DSP） that can tackle compute-intensive functions such as PID Controller， Clark/Park transforms， and Space Vector PWM.
The Xilinx Spartan®-6 FPGA Motor Control Development Kit gives designers an ideal starting point for evaluating time-saving， proven， motor-control reference designs. The kit also shortens the process of developing custom control capabilities， with integrated peripheral functions （Ethernet， PowerLink， and PCI® Express）， a motor-control FPGA mezzanine card （FMC） with built-in Texas Instruments motor drivers and high-precision Delta-Sigma modulators， and prototyping support for evaluating alternative front-end circuitry.
Abstract: As industrial control systems (ICSs) have become increasingly connected and use more off-the-shelfcomponents, new vulnerabilities to cyber attacks have emerged. This tutorial looks at three types of ICSs:programmable logic controllers (PLCs), supervisory control and data acquisition (SCADA) systems, anddistributed control systems (DCSs), and then discusses security issues and remedies. This document alsoexplains the benefits and limitations of two cryptographic solutions (digital signatures and encryption) andelaborates on the reasons for using security ICs in an ICS to support cryptography.
The high defi nition multimedia interface (HDMI) is fastbecoming the de facto standard for passing digitalaudio and video data in home entertainment systems.This standard includes an I2C type bus called a displaydata channel (DDC) that is used to pass extended digitalinterface data (EDID) from the sinkdevice (such as adigital TV) to the source device (such as a digital A/Vreceiver). EDID includes vital information on the digitaldata formats that the sink device can accept. The HDMIspecifi cation requires that devices have less than 50pFof input capacitance on their DDC bus lines, which canbe very diffi cult to meet. The LTC®4300A’s capacitancebuffering feature allows devices to pass the HDMI DDCinput capacitance compliance test with ease.
ACPR (adjacent channel power ratio), AltCPR (alternatechannel power ratio), and noise are important performancemetrics for digital communication systems thatuse, for example, WCDMA (wideband code division multipleaccess) modulation. ACPR and AltCPR are bothmeasures of spectral regrowth. The power in the WCDMAcarrier is measured using a 5MHz measurement bandwidth;see Figure 1. In the case of ACPR, the total powerin a 3.84MHz bandwidth centered at 5MHz (the carrierspacing) away from the center of the outermost carrier ismeasured and compared to the carrier power. The resultis expressed in dBc. For AltCPR, the procedure is thesame, except we center the measurement 10MHz awayfrom the center of the outermost carrier.
This application note discusses a variety of approaches for interfacing analog signals to 5V powered systems. Synthesizing a "rail-to-rail" op amp and scaling techniques for A/D converters are covered. A voltage-to-frequency converter, applicable where high resolution is required, is also presented.
