There has long been a need for portable ultrasoundsystems that have good resolution at affordable costpoints. Portable systems enable healthcare providersto use ultrasound in remote locations such asdisaster zones, developing regions, and battlefields,where it was not previously practical to do so.
This white paper discusses how market trends, the need for increased productivity, and new legislation have
accelerated the use of safety systems in industrial machinery. This TÜV-qualified FPGA design methodology is
changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to
market. This allows FPGA users to design their own customized safety controllers and provides a significant
competitive advantage over traditional microcontroller or ASIC-based designs.
Introduction
The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in
cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas
around machines such as fast-moving robots, and distributed control systems in process automation equipment such
as those used in petrochemical plants.
The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of
electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing
safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was
developed in the mid-1980s and has been revised several times to cover the technical advances in various industries.
In addition, derivative standards have been developed for specific markets and applications that prescribe the
particular requirements on functional safety systems in these industry applications. Example applications include
process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC
62304), automotive (ISO 26262), power generation, distribution, and transportation.
圖Figure 1. Local Safety System
Abstract: There are many things to consider when designing a power supply for a field-programmablegate array (FPGA). These include (but are not limited to) the high number of voltage rails, and thediffering requirements for both sequencing/tracking and the voltage ripple limits. This application noteexplains these and other power-supply considerations that an engineer must think through whendesigning a power supply for an FPGA.
Abstract: Designers who must interface 1-Wire temperature sensors with Xilinx field-programmable gate arrays(FPGAs) can use this reference design to drive a DS28EA00 1-Wire slave device. The downloadable softwarementioned in this document can also be used as a starting point to connect other 1-Wire slave devices. The systemimplements a 1-Wire master connected to a UART and outputs temperature to a PC from the DS28EA00 temperaturesensor. In addition, high/low alarm outputs are displayed from the DS28EA00 PIO pins using LEDs.
In the past decade, the size and complexity of manyFPGA designs exceeds the time and resourcesavailable to most design teams, making the use andreuse of Intellectual Property (IP) imperative.However, integrating numerous IP blocks acquiredfrom both internal and external sources can be adaunting challenge that often extends, rather thanshortens, design time. As today's designs integrateincreasing amounts of functionality, it is vital thatdesigners have access to proven, up-to-date IP fromreliable sources.
The exacting technological demands created byincreasing bandwidth requirements have given riseto significant advances in FPGA technology thatenable engineers to successfully incorporate highspeedI/O interfaces in their designs. One aspect ofdesign that plays an increasingly important role isthat of the FPGA package. As the interfaces get fasterand wider, choosing the right package has becomeone of the key considerations for the systemdesigner.
Xilinx FPGAs require at least two power supplies: VCCINTfor core circuitry and VCCO for I/O interface. For the latestXilinx FPGAs, including Virtex-II Pro, Virtex-II and Spartan-3, a third auxiliary supply, VCCAUX may be needed. Inmost cases, VCCAUX can share a power supply with VCCO.The core voltages, VCCINT, for most Xilinx FPGAs, rangefrom 1.2V to 2.5V. Some mature products have 3V, 3.3Vor 5V core voltages. Table 1 shows the core voltagerequirement for most of the FPGA device families. TypicalI/O voltages (VCCO) vary from 1.2V to 3.3V. The auxiliaryvoltage VCCAUX is 2.5V for Virtex-II Pro and Spartan-3, andis 3.3V for Virtex-II.
FPGAs have changed dramatically since Xilinx first introduced them just 15 years ago. In thepast, FPGA were primarily used for prototyping and lower volume applications; custom ASICswere used for high volume, cost sensitive designs. FPGAs had also been too expensive and tooslow for many applications, let alone for System Level Integration (SLI). Plus, the development
The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. Frequently the messages have meaning; that is they refer to or are correlated according to some system with certain physical or conceptual entities.
USB接口控制器參考設計,xilinx提供VHDL代碼 usb xilinx vhdl
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