亚洲欧美第一页_禁久久精品乱码_粉嫩av一区二区三区免费野_久草精品视频

蟲蟲首頁| 資源下載| 資源專輯| 精品軟件
登錄| 注冊

您現在的位置是:蟲蟲下載站 > 資源下載 > 單片機編程 > 介紹C16x系列微控制器的輸入信號升降時序圖及特性

介紹C16x系列微控制器的輸入信號升降時序圖及特性

資 源 簡 介

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 an
undefined 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 an
application 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 the
TTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usual
and 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 in
the undefined area, well defined low/high levels are generated internally. Note that all
input signals are evaluated at specific sample points (depending on the input and the
peripheral function connected to it), at that signal transitions are detected if two
consecutive samples show different levels. Thus, only the current level of an input signal
at these sample points is relevant, that means, the necessary rise/fall times of the input
signal is only dependant on the sample rate, that is the distance in time between two
consecutive evaluation time points. If an input signal, for instance, is sampled through
software every 10us, it is irrelevant, which input level would be seen between the
samples. Thus, it would be allowable for the signal to take 10us to pass through the
undefined area. Due to the sample rate of 10us, it is assured that only one sample can
occur while the signal is within the undefined area, and no incorrect transition will be
detected. For inputs which are connected to a peripheral function, e.g. capture inputs, the
sample rate is determined by the clock cycle of the peripheral unit. In the case of the
CAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requires
input signals to pass through the undefined area within these 400ns in order to avoid
multiple capture events.

相 關 資 源

主站蜘蛛池模板: 秭归县| 西贡区| 灵川县| 瓦房店市| 二连浩特市| 福建省| 龙泉市| 吴江市| 上蔡县| 通山县| 博客| 百色市| 宁阳县| 南皮县| 密云县| 元谋县| 邢台市| 大关县| 怀安县| 余姚市| 安丘市| 石门县| 同德县| 陵川县| 吉木萨尔县| 信阳市| 汕头市| 沭阳县| 肃宁县| 保亭| 津市市| 钟祥市| 鸡泽县| 小金县| 旬阳县| 余干县| 周至县| 泾源县| 阿拉尔市| 青海省| 辉南县|