BGA布线指南 BGA CHIP PLACEMENT AND ROUTING RULE BGA是PCB上常用的组件,通常CPU、NORTH BRIDGE、SOUTH BRIDGE、AGP CHIP、CARD BUS CHIP…等,大多是以bga的型式包装,简言之,80﹪的高频信号及特殊信号将会由这类型的package内拉出。因此,如何处理BGA package的走线,对重要信号会有很大的影响。 通常环绕在BGA附近的小零件,依重要性为优先级可分为几类: 1. by pass。 2. clock终端RC电路。 3. damping(以串接电阻、排组型式出现;例如memory BUS信号) 4. EMI RC电路(以dampin、C、pull height型式出现;例如USB信号)。 5. 其它特殊电路(依不同的CHIP所加的特殊电路;例如CPU的感温电路)。 6. 40mil以下小电源电路组(以C、L、R等型式出现;此种电路常出现在AGP CHIP or含AGP功能之CHIP附近,透过R、L分隔出不同的电源组)。 7. pull low R、C。 8. 一般小电路组(以R、C、Q、U等型式出现;无走线要求)。 9. pull height R、RP。 中文DOC,共5页,图文并茂
上传时间: 2013-04-24
上传用户:cxy9698
信号与信息处理是信息科学中近几年来发展最为迅速的学科之一,随着片上系统(SOC,System On Chip)时代的到来,FPGA正处于革命性数字信号处理的前沿。基于FPGA的设计可以在系统可再编程及在系统调试,具有吞吐量高,能够更好地防止授权复制、元器件和开发成本进一步降低、开发时间也大大缩短等优点。然而,FPGA器件是基于SRAM结构的编程工艺,掉电后编程信息立即丢失,每次加电时,配置数据都必须重新下载,并且器件支持多种配置方式,所以研究FPGA器件的配置方案在FPGA系统设计中具有极其重要的价值,这也给用于可编程逻辑器件编程的配置接口电路和实验开发设备提出了更高的要求。 本论文基于IEEE1149.1标准和USB2.0技术,完成了FPGA配置接口电路及实验开发板的设计与实现。作者在充分理解IEEE1149.1标准和USB技术原理的基础上,针对Altcra公司专用的USB数据配置电缆USB-Blaster,对其内部工作原理及工作时序进行测试与详细分析,完成了基于USB配置接口的FPGA芯片开发实验电路的完整软硬件设计及功能时序仿真。作者最后进行了软硬件调试,完成测试与验证,实现了对Altera系列PLD的配置功能及实验开发板的功能。 本文讨论的USB下载接口电路被验证能在Altera的QuartusII开发环境下直接使用,无须在主机端另行设计通信软件,其兼容性较现有设计有所提高。由于PLD(Programmable Logic Device)厂商对其知识产权严格保密,使得基于USB接口的配置电路应用受到很大限制,同时也加大了自行对其进行开发设计的难度。 与传统的基于PC并口的下载接口电路相比,本设计的基于USB下载接口电路及FPGA实验开发板具有更高的编程下载速率、支持热插拔、体积小、便于携带、降低对PC硬件伤害,且具备其它下载接口电路不具备的SignalTapII嵌入式逻辑分析仪和调试NiosII嵌入式软核处理器等明显优势。从成本来看,本设计的USB配置接口电路及FPGA实验开发板与其同类产品相比有较强的竞争力。
上传时间: 2013-06-07
上传用户:2525775
FEATURES Unique 1-Wire interface requires only one port pin for communication Multidrop capability simplifies distributed temperature sensing applications Requires no external components Can be powered from data line. Power supply range is 3.0V to 5.5V Zero standby power required Measures temperatures from -55°C to +125°C. Fahrenheit equivalent is -67°F to +257°F ±0.5°C accuracy from -10°C to +85°C Thermometer resolution is programmable from 9 to 12 bits Converts 12-bit temperature to digital word in 750 ms (max.) User-definable, nonvolatile temperature alarm settings Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition) Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system
上传时间: 2013-08-04
上传用户:CHENKAI
·详细说明:Actions 炬力 MP3 播放器2071、2073系列主控芯片 参考电路图,完整电路图。-Actions the torch strength MP3 player 2,071, 2,073 series hosts control the chip reference circuit diagram, complete circuit diagram.
上传时间: 2013-04-24
上传用户:amwfhv
·基本信息Practical Antenna Handbook, 4th EditionbyJoseph J.Carr作者 Jeseph J. Carr 美国国防部航空电子(avionics)资深工程师one of the worlds leading and prolific writer and working scientist on electronics and radio, and an
标签: nbsp Practical Handbook Antenna
上传时间: 2013-04-24
上传用户:yare
读取STM32芯片内部唯一的标识,用于加密等区别其他芯片的操作,有完整注释,测试通过-STM32 chip to read a unique identifier for the encryption and other differences other chip operation, with complete notes, test
上传时间: 2013-05-24
上传用户:793212294
VHDL source codes of the FPGA64, a fpga implementation of the C64 computer. Version for the c-one fpga board.
上传时间: 2013-08-05
上传用户:wwwe
本文简单讨论并总结了VHDL、Verilog,System verilog 这三中语言的各自特点和区别As the number of enhancements to variousHardware Description Languages (HDLs) hasincreased over the past year, so too has the complexityof determining which language is best fora particular design. Many designers and organizationsare contemplating whether they shouldswitch from one HDL to another.
标签: Verilog verilog System VHDL
上传时间: 2013-10-16
上传用户:牛布牛
One of the most misunderstood constructs in the Verilog language is the nonblockingassignment. Even very experienced Verilog designers do not fully understand how nonblockingassignments are scheduled in an IEEE compliant Verilog simulator and do not understand whenand why nonblocking assignments should be used. This paper details how Verilog blocking andnonblocking assignments are scheduled, gives important coding guidelines to infer correctsynthesizable logic and details coding styles to avoid Verilog simulation race conditions
上传时间: 2013-10-17
上传用户:tb_6877751
Abstract: Many digital devices incorporate analog circuits. For instance, microprocessors, applicationspecificintegrated circuits (ASICs), and field-programmable gate arrays (FPGAs) may have internalvoltage references, analog-to-digital converters (ADCs) or digital-to-analog converters (DACs). However,there are challenges when you integrate more analog onto a digital design. As with all things in life, inelectronics we must always trade one parameter for another, with the application dictating the propertrade-off of analog function. In this application note, we examine how the demand for economy of spaceand cost pushes analog circuits onto digital substrates, and what design challenges emerge.
上传时间: 2013-11-17
上传用户:菁菁聆听