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
設計一種應用于某全地形ATV車載武器裝置中的中控系統,該系統設計是以TMS320F2812型DSP為核心,采用模塊化設計思想,對其硬件部分進行系統設計,能夠完成對武器裝置高低、回轉方向的運動控制,實現靜止或行進狀態中對目標物的測距,自動瞄準以及按既定發射模式發射彈丸和各項安全性能檢測等功能。通過編制相應的軟件,對其進行系統調試,驗證了該設計運行穩定。 Abstract: A central control system applied to an ATV vehicle weapons is designed. The system design is based on TMS320F2812 DSP as the core, uses modular design for its hardware parts. The central control system can complete the motion control of the level of weapons and equipment, rotation direction, to achieve a state of static or moving objects on the target ranging, auto-targeting and according to the established target and the projectile and the launch of the security performance testing and other functions. Through the development of appropriate software and to carry out system testing to verify the stability of this design and operation.
上傳時間: 2013-11-02
上傳用戶:jshailingzzh
智能平臺體感慣性傳感器應用 智能互聯 物聯傳感 操作系統 體感 慣性傳感 人機接口 windows8 android
標簽: integrating-motion-and-orientatio n-sensors 智能平臺 傳感器
上傳時間: 2013-10-07
上傳用戶:Ants
Abstract: This reference design provides design ideas for a cost-effective, low-power liquid-level measurement dataacquisition system (DAS) using a compensated silicon pressure sensor and a high-precision delta-sigma ADC. Thisdocument discusses how to select the compensated silicon pressure sensor, suggest system algorithms, and providenoise analyses. It also describes calibration ideas to improve system performance while also reducing complexity andcost.
上傳時間: 2013-10-08
上傳用戶:sjy1991
STM32
上傳時間: 2013-10-13
上傳用戶:jdm439922924
STM32
上傳時間: 2014-10-30
上傳用戶:tianyi996
The Circuit Designer’s Companion Second edition Tim Williams
標簽: Designers Companion Circuit PCB
上傳時間: 2013-10-08
上傳用戶:sxdtlqqjl
Silicon Motion, Inc. has made best efforts to ensure that the information contained in this document is accurate andreliable. However, the information is subject to change without notice. No responsibility is assumed by SiliconMotion, Inc. for the use of this information, nor for infringements of patents or other rights of third parties.Copyright NoticeCopyright 2002, Silicon Motion, Inc. All rights reserved. No part of this publication may be reproduced, photocopied,or transmitted in any form, without the prior written consent of Silicon Motion, Inc. Silicon Motion, Inc. reserves theright to make changes to the product specification without reservation and without notice to our users
標簽: GUIDELINES LAYOUT 320 PCB
上傳時間: 2013-10-10
上傳用戶:manga135
國外游戲開發者雜志2001年第八期配套代碼,包含Tim Schoeder在Volition Red Faction使用到的碰撞探測系統源代碼
上傳時間: 2013-12-21
上傳用戶:蠢蠢66
The cart with an inverted pendulum, shown below, is "bumped" with an impulse force, F. Determine the dynamic equations of motion for the system, and lin earize about the pendulum s angle, theta = Pi (in other words, assume that p endulum does not move more than a few degrees away from the vertical, chosen to be at an angle of Pi). Find a controller to satisfy all of the design re quirements given below.
標簽: F. with Determine inverted
上傳時間: 2014-01-17
上傳用戶:miaochun888