This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.
上傳時間： 2014-01-24
上傳用戶：s363994250
伺服驅動器
上傳時間： 2013-12-25
上傳用戶：偷心的海盜
特點 精確度0.1%滿刻度±1位數 可直接量測交直流電壓(AC/DC 20~265V)無需另接電源 精密濾波整流,均方根值校正 尺寸小(24x48x50mm),穩定性 分離式端子,配線容易 CE認證
上傳時間： 2013-11-05
上傳用戶：gaome
SL811開發資料_包含源程序_電路圖_芯片資料:SL811HS Embedded USB Host/Slave Controller.The SL811HS is an Embedded USB Host/Slave Controller capable of communicate with either full-speed or low-speed USB peripherals. The SL811HS can interface to devices such as microprocessors, microcontrollers, DSPs, or directly to a variety of buses such as ISA, PCMCIA, and others. The SL811HS USB Host Controller conforms to USB Specification 1.1.The SL811HS USB Host/Slave Controller incorporates USB Serial Interface functionality along with internal full-/low-speed transceivers.The SL811HS supports and operates in USB full-speed mode at 12 Mbps, or at low-speed 1.5-Mbps mode.The SL811HS data port and microprocessor interface provide an 8-bit data path I/O or DMA bidirectional, with interrupt support to allow easy interface to standard microprocessors or microcontrollers such as Motorola or Intel CPUs and many others. Internally,the SL811HS contains a 256-byte RAM data buffer which is used for control registers and data buffer.The available package types offered are a 28-pin PLCC (SL811HS) and a 48-pin TQFP package (SL811HST-AC). Both packages operate at 3.3 VDC. The I/O interface logic is 5V-tolerant.
上傳時間： 2013-12-22
上傳用戶：a82531317
介紹了以PLC為控制單元，變頻器為執行單元的控制系統及其在煙支輸送儲存系統中的應用，并給出了系統的組成、硬件的配置及具體的實現方法。關鍵詞 : PLC 變頻器輸送儲存系統 Ab str ac t;T hisp aperi ntroducest hec ontrols ystem whichc onsistso fP LCa ndf requencyc onvertera ndi ts application in the buffer conveyor for cigarettes. The system constitute, hardware disposal and realization method are also presented in detail.Keywords:PLC f requencyc onverter b ufferc onveyor
上傳時間： 2013-10-22
上傳用戶：ouyang426
本“計算器”可以完成任意的通常借助手持計算器來完成的標準運算。“計算器”可用于基本的算術運算，比如加減運算等，以及C（清除）、AC（全部清零）、N（符號改變）、存儲（M＋、M－、MR）、平方根和百分比運算。關于科學計算本“計算器”暫不支持。
上傳時間： 2014-10-28
上傳用戶：BOBOniu
apache.org/commons/fileupload/下載。由于本人...關鍵步驟中的相關 操作為: 1) 在init(),用實例變量....1\db\db.prp idb.maxconn=2 access. url=jdbc:... URL,而且訪問該數據庫要使用JDBC-ODBC驅動程序。...
標簽： fileupload commons maxconn apache
上傳時間： 2013-12-18
上傳用戶：gxrui1991
Fourier-Mellin算法，更多細節請看下面的網址： http://www.ecs.soton.ac.uk/~aiw99r/fm_transform/
標簽： Fourier-Mellin 算法
上傳時間： 2014-01-05
上傳用戶：kristycreasy
1997年9月，NIST征集AES方案，以替代DES。 1999年8月，以下5個方案成為最終候選方案：MARS, RC6, Rijndael, Serpent, Twofish。 2000年10月，由比利時的Joan Daemen和Vincent Rijmen提出的算法最終勝出。（ Rijndael 讀成Rain Doll。） http://www.esat.kuleuven.ac.be/~rijmen/rijndael/
標簽： 1997
上傳時間： 2014-01-19
上傳用戶：希醬大魔王
操作系統中的文件是通過文件目錄項來管理的，為了管理和查找的方便，按層次把文件目錄項組織起來，同一層上的目錄構成該層上的目錄，第一層為根目錄，一下為各層子目錄。 假設以一串字符代表一個文件，每個字符表示一個記錄。 在建立上述目錄結構的基礎上，建立相應的管理系統并要求完成以下各項操作： 1． 一次建立各個文件 2． 查訪兩個用戶的所有文件 3． 查訪用戶sun 是否有文件AB 4． 刪除用戶sun的文件AC,然后在分別查訪兩個用戶的全部文件，檢查是否已經刪除文件AC 5． 撤銷用戶sun,并檢查是否被刪除 6． 刪除用戶sun的全部文件，然后在撤銷sun用戶，在查訪用戶sun, 檢查其是否已被撤銷。 在建立一個新用戶及新用戶的兩個文件，然后查該兩個用戶的所有文件
上傳時間： 2014-01-23
上傳用戶：xhz1993
