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C16x

  • 介绍C16x系列微控制器的输入信号升降时序图及特性

    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.

    标签: C16x 微控制器 输入信号 时序图

    上传时间: 2014-04-02

    上传用户:han_zh

  • Input Signal Rise and Fall Tim

    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.

    标签: Signal Input Fall Rise

    上传时间: 2013-10-23

    上传用户:copu

  • VIP专区-单片机源代码精选合集系列(72)

    eeworm.com VIP专区 单片机源码系列 71资源包含以下内容:1. PWM模块单片机的步进电机细分驱动的理论和方法介绍.pdf2. 基于状态分析的键盘管理软件设计.pdf3. 单片机的步进电机控制器设计介绍.pdf4. 单片机温度控制系统的设计及实现.pdf5. 基于单片机的步进电机细分技术介绍.pdf6. 基于单片机的太阳能电池自动跟踪系统的设计.zip7. 单片机的步进电机细分技术研究介绍.pdf8. 气体压缩因子Z的在线修正与单片机实现.pdf9. Emulating a synchronous serial.pdf10. 基于单片机的霍尔传感器测试系统介绍.pdf11. 使用软件程序仿真C500微控制器系列SSC(同步串行通道)功.pdf12. MPC106 PCI Bridge/Memory Contr.pdf13. 单片机以太网通讯的实现介绍.pdf14. MPC106 PCI桥/存储器控制器硬件规范说明.pdf15. USB Demonstration for DK3200 w.pdf16. 对带有uPSD3234A的DK3200的USB演示.pdf17. An easy way to work with Exter.pdf18. 用外部设备设置32位微控制器TriCore的中断的指令及方法.pdf19. P90CL301 I2C driver routines.pdf20. Input Signal Rise and Fall Tim.pdf21. P90CL301 IIC驱动电路的例行测试及其程序.pdf22. 用51单片机实现公历与农历星期的转换.pdf23. 介绍C16x系列微控制器的输入信号升降时序图及特性.pdf24. XA-S3 I2C driver software.pdf25. 万年历算法.pdf26. MCS-51单片机对步进电机控制的实现.pdf27. XA-S3的IIC接口的驱动器软件程序(C语言).pdf28. Reading and Writing iButtons v.pdf29. 通用单片机试验板原理图.pdf30. I2C slave routines for the 87L.pdf31. Philips微控制器在LIN中的应用.pdf32. MPC7400 Part Number Speci&THOR.pdf33. 87LPC76X的IIC从程序.pdf34. 基于P87C591的CAN总线系统智能节点设计.pdf35. MPC7400l零件号码规范说明.pdf36. Using the 87LPC76X microcontro.pdf37. Control System of Stepp ingMot.pdf38. 68HC05K0 Infra-red Remote Cont.pdf39. 87C576微控制器的在线编程.pdf40. CAN与RS232转换节点的设计与实现.pdf41. 68HC05K0实现红外远程控制键盘的应用.pdf42. 单片机外围线路设计.rar43. 单片机常用芯片和器件手册.rar44. IO口状态切换说明.pdf45. 中断技术.ppt.ppt46. 并行接口.ppt47. DMA技术 -ppt.ppt48. 结构紧凑的Li+电池充电器.pdf49. 定时与计数技术.ppt50. 微机总线与接口标准.ppt51. 中断的概念及51单片机的中断系统.ppt52. 输入输出与接口技术.ppt53. 单片机应用概述.ppt54. 现代微机原理与接口技术.rar55. 单片机应用系统设计的基本方法.ppt56. PCB可测性设计布线规则之建议―从源头改善可测率.pdf57. 单片机A/D和D/A应用接口技术.ppt58. 汇编语言上机过程.ppt.ppt59. PWM的调速原理与应用—小车调速.ppt60. 汇编语言在数据处理中的应用.ppt61. 定时器/计数器基础.ppt62. 驱动程序与应用程序的接口.doc63. 外部中断应用程序设计范例.ppt64. 实验指导书 (TPC-H实验台C语言版).pdf65. 汇编语言程序设计案例—动态显示/障碍物检测/障碍物方位检测.rar66. 指令功能及汇编语言程序设计.rar67. ispdown V2.3 最新版 (可用Altera下载线进.rar68. MCS-51单片机的编程应用范例.pdf69. 51编程指南--MCSÉ-51 Program.rar70. 多运动目标跟踪及连通域标记方法.pdf71. 很经典的仿真器自制资料.rar72. mcs-51指令集.rar73. 自制51单片机编程器.rar74. CAN总线与USB的转接技术.pdf75. 自制ATMEL 89系列FLASH单片机编程器.rar76. 基于ARM处理器LPC2142的高速数据采集卡设计.pdf77. 微机测量系统中的抗干扰措施.pdf78. PGM89 51Flash单片机编程器V3.0.rar79. 改善基于微控制器的应用的瞬态免疫性能.rar80. KEIL C51开发软件操作使用视频教程.rar81. 自制微型51/AVR通用编程器.rar82. C51单片机视频教程.RAR83. 自制51编程器资料.rar84. 基于单片机89C51和89C2051点阵LED图文显示.pdf85. 全遥控6声道AV机的汇编程序.rar86. keil c51中文说明.pdf87. 基于AT89C2051的红外遥控学习器源程序.rar88. 微型计算机课程设计论文—通用微机发声程序的汇编设计.rar89. 从PCI总线的-12V电源获得3.3V电压.pdf90. DS1302+AT89S52+LED时钟程序(C语言源代码+.rar91. 乐曲发声及动画程序.rar92. 单片开关电源的设计和应用.rar93. 51单片机试验板电路图-原理图.rar94. DS1820 C51 子程序 (一线数据传输).doc95. 模拟串口通讯程序(51汇编代码编写).doc96. 8051单片机教程 (word版).rar97. 串行编程器源程序(Keil C语言).rar98. 用C51写的普通拼音输入法源程序代码.zip99. EasyIsp下载线电路图.rar100. 采用18b20芯片的温度测量C51源程序.rar

    标签: 传感器 检测技术

    上传时间: 2013-06-02

    上传用户:eeworm