数字与模拟电路设计技巧IC与LSI的功能大幅提升使得高压电路与电力电路除外,几乎所有的电路都是由半导体组件所构成,虽然半导体组件高速、高频化时会有EMI的困扰,不过为了充分发挥半导体组件应有的性能,电路板设计与封装技术仍具有决定性的影响。 模拟与数字技术的融合由于IC与LSI半导体本身的高速化,同时为了使机器达到正常动作的目的,因此技术上的跨越竞争越来越激烈。虽然构成系统的电路未必有cLock设计,但是毫无疑问的是系统的可靠度是建立在电子组件的选用、封装技术、电路设计与成本,以及如何防止噪讯的产生与噪讯外漏等综合考虑。机器小型化、高速化、多功能化使得低频/高频、大功率信号/小功率信号、高输出阻抗/低输出阻抗、大电流/小电流、模拟/数字电路,经常出现在同一个高封装密度电路板,设计者身处如此的环境必需面对前所未有的设计思维挑战,例如高稳定性电路与吵杂(noisy)性电路为邻时,如果未将噪讯入侵高稳定性电路的对策视为设计重点,事后反复的设计变更往往成为无解的梦魇。模拟电路与高速数字电路混合设计也是如此,假设微小模拟信号增幅后再将full scale 5V的模拟信号,利用10bit A/D转换器转换成数字信号,由于分割幅宽祇有4.9mV,因此要正确读取该电压level并非易事,结果造成10bit以上的A/D转换器面临无法顺利运作的窘境。另一典型实例是使用示波器量测某数字电路基板两点相隔10cm的ground电位,理论上ground电位应该是零,然而实际上却可观测到4.9mV数倍甚至数十倍的脉冲噪讯(pulse noise),如果该电位差是由模拟与数字混合电路的grand所造成的话,要测得4.9 mV的信号根本是不可能的事情,也就是说为了使模拟与数字混合电路顺利动作,必需在封装与电路设计有相对的对策,尤其是数字电路switching时,ground vance noise不会入侵analogue ground的防护对策,同时还需充分检讨各电路产生的电流回路(route)与电流大小,依此结果排除各种可能的干扰因素。以上介绍的实例都是设计模拟与数字混合电路时经常遇到的瓶颈,如果是设计12bit以上A/D转换器时,它的困难度会更加复杂。
上传时间: 2014-02-12
上传用户:wenyuoo
本文利用Verilog HDL 语言自顶向下的设计方法设计多功能数字钟,突出了其作为硬件描述语言的良好的可读性、可移植性和易理解等优点,并通过Altera QuartusⅡ 4.1 和ModelSim SE 6.0 完成综合、仿真。此程序通过下载到FPGA 芯片后,可应用于实际的数字钟显示中。 关键词:Verilog HDL;硬件描述语言;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
上传时间: 2013-11-10
上传用户:hz07104032
LAYOUT REPORT .............. 1 目錄.................. 1 1. PCB LAYOUT 術語解釋(TERMS)......... 2 2. Test Point : ATE 測試點供工廠ICT 測試治具使用............ 2 3. 基準點 (光學點) -for SMD:........... 4 4. 標記 (LABEL ING)......... 5 5. VIA HOLE PAD................. 5 6. PCB Layer 排列方式...... 5 7.零件佈置注意事項 (PLACEMENT NOTES)............... 5 8. PCB LAYOUT 設計............ 6 9. Transmission Line ( 傳輸線 )..... 8 10.General Guidelines – 跨Plane.. 8 11. General Guidelines – 繞線....... 9 12. General Guidelines – Damping Resistor. 10 13. General Guidelines - RJ45 to Transformer................. 10 14. cLock Routing Guideline........... 12 15. OSC & CRYSTAL Guideline........... 12 16. CPU
上传时间: 2013-10-29
上传用户:1234xhb
a8259 可编程中断控制 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.
上传时间: 2015-01-02
上传用户:panpanpan
Abstract: This application note explains how to design an intelligent lighting controller that senses and measures the ambient lightlevel with an ambient light sensor (ALS). Equipped with a real-time cLock (RTC), the controller also knows when to turn lighting on oroff at specified times. The system presented in this document can be used to control all luminaires that are mains-supply operated.Controller software is also provided in hex format.
上传时间: 2013-11-18
上传用户:AbuGe
The data plane of the reference design consists of a configurable multi-channel XBERT modulethat generates and checks high-speed serial data transmitted and received by the MGTs. Eachchannel in the XBERT module consists of two MGTs (MGTA and MGTB), which physicallyoccupy one MGT tile in the Virtex-4 FPGA. Each MGT has its own pattern checker, but bothMGTs in a channel share the same pattern generator. Each channel can load a differentpattern. The MGT serial rate depends on the reference cLock frequency and the internal PMAdivider settings. The reference design can be scaled anywhere from one channel (two MGTs)to twelve channels (twenty-four MGTs).
上传时间: 2013-12-25
上传用户:jkhjkh1982
S3C44BOX的BIOS。可使用的命令:help --- show help ? --- = help date --- show or set current date time --- show or set current time setweek --- set weekday cLock --- show system running cLock setmclk --- set system running cLock setbaud ------ set baud rate ipcfg ------ show or set IP address load ------ load file to ram comload ------ load file from serial port run ------ run from sdram prog ------ program flash copy ------ copy flash from src to dst address boot ------ boot from flash backup ------ move bios to the top of flash md ------ show memory data move ------ move program from flash to sdram
上传时间: 2015-01-22
上传用户:ANRAN
本程序是一个用汇编编的精致的图形时钟,运行时双击cLock图标即可,钟表显示的时间为本机系统的时间。 按b键可扩大画面 ;按s键可缩小画面;按c键可改变颜色;按e键可听音乐;按q键退出本程序.
上传时间: 2014-01-16
上传用户:qlpqlq
减1计数器 一、设计要求 用Verilog HDL语言设计一个计数器。 要求计数器具有异步置位/复位功能,可以进行自增和自减计数,其计数周期为2^N(N为二进制位数)。 二、设计原理 输入/输出说明: d:异步置数数据输入; q:当前计数器数据输出; cLock:时钟脉冲; count_en:计数器计数使能控制(1:计数/0:停止计数); updown:计数器进行自加/自减运算控制(1:自加/0:自减); load_d
上传时间: 2015-03-28
上传用户:zycidjl
dsp2407的函数库,c语言编写,有io,adc,cLock等
上传时间: 2015-04-04
上传用户:iswlkje