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.
上传时间: 2013-10-23
上传用户:copu
prolog 找路例子程序: === === === === === === Part 1-Adding connections Part 2-Simple Path example | ?- path1(a,b,P,T). will produce the response: T = 15 P = [a,b] ? Part 3 - Non-repeating path As an example, the query: ?- path2(a,h,P,T). will succeed and may produce the bindings: P = [a,depot,b,d,e,f,h] T = 155 Part 4 - Generating a path below a cost threshold As an example, the query: ?- path_below_cost(a,[a,b,c,d,e,f,g,h],RS,300). returns: RS = [a,b,depot,c,d,e,g,f,h] ? RS = [a,c,depot,b,d,e,g,f,h] ? no ==================================
标签: Part connections example prolog
上传时间: 2015-04-24
上传用户:ljt101007
1、 了解系统调用fork()、execl()、exit()、getpid()和waitpid()的功能和实现过程 2、 编写一段程序实现以下功能: a) 使用系统调用fork()创建两个子进程 b) 父进程重复显示字符串”parent:”,并使用函数getpid()显示自己的进程ID。 c) 两个子进程分别重复显示字符串”child:”,并使用函数getpid()显示自己的进程ID 3、 编写一段程序实现以下功能: a) 使用系统调用fork()创建一个子进程 b) 子进程显示自己的进程ID和字符串": The child is calling an exec.\n",然后通过execl()调用系统命令ps显示当前运行的进程情况,从而更换自己的执行代码,最后调用exit()结束。 c) 父进程显示自己的进程ID和字符串” ": The parent is waiting for child to exit.\n ",然后调用waitpid()等待子进程结束,并在子进程结束后显示”The parent exit.\n
上传时间: 2013-12-18
上传用户:叶山豪
The book "The Finite Difference Time Domain for Electromagnetics" by Karl Kunz and Raymond Luebbers, CRC Press, 1993, contains an FDTD code and output files in Appendix B. The same code and output files are contained in this directory.
标签: Electromagnetics Difference The Luebbers
上传时间: 2013-12-29
上传用户:chongcongying
Implemented BFS, DFS and A* To compile this project, use the following command: g++ -o search main.cpp Then you can run it: ./search The input is loaded from a input file in.txt Here is the format of the input file: The first line of the input file shoud contain two chars indicate the source and destination city for breadth first and depth first algorithm. The second line of input file shoud be an integer m indicate the number of connections for the map. Following m lines describe the map, each line represents to one connection in this form: dist city1 city2, which means there is a connection between city1 and city2 with the distance dist. The following input are for A* The following line contains two chars indicate the source and destination city for A* algorithm. Then there is an integer h indicate the number of heuristic. The following h lines is in the form: city dist which means the straight-line distance from the city to B is dist.
标签: Implemented following compile command
上传时间: 2014-01-01
上传用户:lhc9102
Atheros无线芯片AR-6000系列wince 6驱动源代码(这东西我也没用过别问我,我是搜别的wince资源搜到的) AR6K SDIO support. Requires firmware 1.1 on SD13 cards. readme: Atheros Communications AR6001 WLAN Driver for SDIO installation Read Me March 26,2007 (based on k14 fw1.1) Windows CE Embedded CE 6.0 driver installation. 1. Unzip the installation file onto your system (called installation directory below) 2. Create an OS design or open an existing OS design in Platform Builder 6.0. a. The OS must support the SD bus driver and have an SD Host Controller driver (add these from Catalog Items). b. Run image size should be set to allow greater than 32MB. 3. a. From the Project menu select Add Existing Subproject... b. select AR6K_DRV.pbxml c. select open This should create a subproject within your OS Design project for the AR6K_DRV driver. 4. Build the solution. 转自Tony嵌入式,原文地址:http://www.cevx.com/bbs/dispbbs.asp?boardID=4&ID=11762&page=1
标签: wince Requires firmware Atheros
上传时间: 2014-11-11
上传用户:bibirnovis
1) Write a function reverse(A) which takes a matrix A of arbitrary dimensions as input and returns a matrix B consisting of the columns of A in reverse order. Thus for example, if A = 1 2 3 then B = 3 2 1 4 5 6 6 5 4 7 8 9 9 8 7 Write a main program to call reverse(A) for the matrix A = magic(5). Print to the screen both A and reverse(A). 2) Write a program which accepts an input k from the keyboard, and which prints out the smallest fibonacci number that is at least as large as k. The program should also print out its position in the fibonacci sequence. Here is a sample of input and output: Enter k>0: 100 144 is the smallest fibonacci number greater than or equal to 100. It is the 12th fibonacci number.
标签: dimensions arbitrary function reverse
上传时间: 2016-04-16
上传用户:waitingfy
本实训是有关线性表的顺序存储结构的应用,在本实训的实例程序中,通过C语言中提供的数组来存储两个已知的线性表,然后利用数组元素的下标来对线性表进行比较。通过对本实训的学习,可以理解线性表在顺序存储结构下的操作方法。 在实训中,我们设A=(a1,a2,…,an)和B=(b1,b2,…,bm)是两个线性表,其数据元素的类型是整型。若n=m,且ai=bi,则称A=B 若ai=bi,而aj<bj,则称A<B;除此以外,均称A>B。设计一比较大小的程序。
上传时间: 2014-01-14
上传用户:www240697738
Trie树既可用于一般的字典搜索,也可用于索引查找。对于给定的一个字符串a1,a2,a3,...,an.则采用TRIE树搜索经过n次搜索即可完成一次查找。不过好像还是没有B树的搜索效率高,B树搜索算法复杂度为logt(n+1/2).当t趋向大,搜索效率变得高效。怪不得DB2的访问内存设置为虚拟内存的一个PAGE大小,而且帧切换频率降低,无需经常的PAGE切换。
上传时间: 2016-07-06
上传用户:sk5201314
可编程并行接口8255A完成的交通灯实验 用8255A的B端口和C端口控制12个LED的亮和灭(输出为0则亮,输出为1则灭),模拟十字路口的交通灯。 -programmable parallel interface 8255A completed, the traffic lights experimental 8255A port B and C - I control 12 LED bright and methomyl (output of 0-liang, the output of an anti), the simulation of traffic lights at a crossroads.
上传时间: 2016-08-13
上传用户:来茴