All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.For input signals, which do not provide the required rise/fall times, external circuitry mustbe used to shape the signal transitions.In the attached diagram, the effect of the sample rate is shown. The numbers 1 to 5 in thediagram represent possible sample points. Waveform a) shows the result if the inputsignal transition time through the undefined TTL-level area is less than the time distancebetween the sample points (sampling at 1, 2, 3, and 4). Waveform b) can be the result ifthe sampling is performed more than once within the undefined area (sampling at 1, 2, 5,3, and 4).Sample points:1. Evaluation of the signal clearly results in a low level2. Either a low or a high level can be sampled here. If low is sampled, no transition willbe detected. If the sample results in a high level, a transition is detected, and anappropriate action (e.g. capture) might take place.3. Evaluation here clearly results in a high level. If the previous sample 2) had alreadydetected a high, there is no change. If the previous sample 2) showed a low, atransition from low to high is detected now.
上傳時間: 2013-10-23
上傳用戶:copu
附件有51單片機加上sl811讀寫U盤的源程序和原理圖 /*--------------------------------------------------------------------------AT89X52.H Header file for the low voltage Flash Atmel AT89C52 and AT89LV52.Copyright (c) 1995-1996 Keil Software, Inc. All rights reserved.--------------------------------------------------------------------------*/ #ifndef AT89X52_HEADER_FILE#define AT89X52_HEADER_FILE 1 /*------------------------------------------------Byte Registers------------------------------------------------*/sfr P0 = 0x80;sfr SP = 0x81;sfr DPL = 0x82;sfr DPH = 0x83;sfr PCON = 0x87;sfr TCON = 0x88;sfr TMOD = 0x89;sfr TL0 = 0x8A;sfr TL1 = 0x8B;sfr TH0 = 0x8C;sfr TH1 = 0x8D;sfr P1 = 0x90;sfr SCON = 0x98;sfr SBUF = 0x99;sfr P2 = 0xA0;sfr IE = 0xA8;sfr P3 = 0xB0;sfr IP = 0xB8;sfr T2CON = 0xC8;sfr T2MOD = 0xC9;sfr RCAP2L = 0xCA;sfr RCAP2H = 0xCB;sfr TL2 = 0xCC;sfr TH2 = 0xCD;sfr PSW = 0xD0;sfr ACC = 0xE0;sfr B = 0xF0;
上傳時間: 2014-01-05
上傳用戶:lnnn30
software management\Software Develop Guide
標簽: managementSoftware software Develop Guide
上傳時間: 2014-01-24
上傳用戶:wanghui2438
This book is about the management of business processes. This is certainly not a new topic. Since the beginning of the Industrial Revolution, it has been written about from every possible point of view—economic, sociological, psychological, accountancy, mechanical engineering and business administration. In this book, we examine the management of business processes from the perspective of computing, or—to put it more broadly—of information technology. The reason is that information technology has made huge leaps forward in recent years, resulting in the creation of completely new ways of organizing business processes. The development of generic software packages for managing business processes—so-called workflow management systems (WFMS)—is particularly important in this respect.
標簽: This management certainly processes
上傳時間: 2013-11-29
上傳用戶:shus521
by Randal L. Schwartz and Tom Phoenix ISBN 0-596-00132-0 Third Edition, published July 2001. (See the catalog page for this book.) the text of Learning Perl, 3rd Edition. Table of Contents Copyright Page Preface Chapter 1: Introduction Chapter 2: Scalar Data Chapter 3: Lists and Arrays Chapter 4: Subroutines Chapter 5: Hashes Chapter 6: I/O Basics Chapter 7: Concepts of Regular Expressions Chapter 8: More About Regular Expressions Chapter 9: Using Regular Expressions Chapter 10: More Control Structures Chapter 11: Filehandles and File Tests Chapter 12: Directory Operations Chapter 13: Manipulating Files and Directories Chapter 14: Process Management Chapter 15: Strings and Sorting Chapter 16: Simple Databases Chapter 17: Some Advanced Perl Techniques Appendix A: Exercise Answers Appendix B: Beyond the Llama Index Colophon
標簽: L. published Schwartz Edition
上傳時間: 2014-11-29
上傳用戶:kr770906
by Randal L. Schwartz and Tom Phoenix ISBN 0-596-00132-0 Third Edition, published July 2001. (See the catalog page for this book.) Learning Perl, 3rd Edition. Table of Contents Copyright Page Preface Chapter 1: Introduction Chapter 2: Scalar Data Chapter 3: Lists and Arrays Chapter 4: Subroutines Chapter 5: Hashes Chapter 6: I/O Basics Chapter 7: Concepts of Regular Expressions Chapter 8: More About Regular Expressions Chapter 9: Using Regular Expressions Chapter 10: More Control Structures Chapter 11: Filehandles and File Tests Chapter 12: Directory Operations Chapter 13: Manipulating Files and Directories Chapter 14: Process Management Chapter 15: Strings and Sorting Chapter 16: Simple Databases Chapter 17: Some Advanced Perl Techniques Appendix A: Exercise Answers Appendix B: Beyond the Llama Index Colophon
標簽: L. published Schwartz Edition
上傳時間: 2015-09-03
上傳用戶:lifangyuan12
About: Paco (pacKAGE oRGANIZER) is a simple, yet powerful tool to aid package management when installing programs from source code. It uses the LD_PRELOAD method to track package installations, and provides various options to keep the installed software organized. It s mainly a command line application but it has also an optional GTKMM interface. Release focus: Minor bugfixes Changes: Libpaco-log has been rewritten in C. This prevents a glibc installation failure when building LFS in chapter 6. The option -x|--expand has been removed. Several bugs have been fixed in paco, gpaco, and rpm2paco. Author: David Rosal
標簽: management oRGANIZER powerful pacKAGE
上傳時間: 2014-08-25
上傳用戶:weixiao99
The Original USB 2.0 specification released on April 27, 2000 Errata to the USB 2.0 specification as of December 7, 2000 Mini-B connector Engineering Change Notice to the USB 2.0 specification. Pull-up/pull-down Resistors Engineering Change Notice to the USB 2.0 specification. Errata to the USB 2.0 specification as of May 28, 2002 Interface Association Descriptor Engineering Change Notice to the USB 2.0 specification. Rounded Chamfer Engineering Change Notice to the USB 2.0 specification as of October 8, 2003 Unicode Engineering Change Notice to the USB 2.0 specification as of February 21, 2005 Inter-Chip USB Supplement Revision 1.0 as of March 13, 2006 Revision 1.3 of the USB On-The-Go Supplement as of December 5, 2006 Revision 1.01 of the Micro-USB Cables and Connectors Specification as of April 4, 2007 USB 2.0 Link Power Management Addendum Engineering Change Notice to the USB 2.0 specification as of July 16, 2007.
標簽: specification 2.0 USB Original
上傳時間: 2013-12-31
上傳用戶:familiarsmile
The IA-32 Software Developer’s Manual, Volume 3: System Programming Guide (Order Number 245472), is part of a three-volume set that describes the architecture and programming environment of all IA-32 Intel® Architecture processors. The IA-32 Software Developer’s Manual, Volume 3, describes the operating-system support environment of an IA-32 processor, including memory management, protection, task management, interrupt and exception handling, and system management mode. It also provides IA-32 processor compatibility information. This volume is aimed at operating- system and BIOS designers and programmers.
標簽: Programming Developer Software 245472
上傳時間: 2013-12-23
上傳用戶:小碼農lz
T-kernel 的extension源代碼,是日本最著名的T-kernel所獨有的,適合開發T-kernel的朋友們使用! TK/SE is the program that extends T-Kernel and provides the functions such as a file system and a process management. The TK/SE archive to be provided is comprised of the main portion and the 2 extended file system portions, and TK/SE object is built by adding these to T-Kernel source. a) tkernel_se_1.00.00.tar.gz Main source of T-Kernel/SE b) extfs_fatfs_1.00.00.tar.gz Difference source of T-Kernel/SE extended file system (FAT) c) extfs_cdrom_1.00.00.tar.gz Difference source of T-Kernel/SE extended file system (CD-ROM)
上傳時間: 2014-01-20
上傳用戶:czl10052678