时钟

Clock sources are 508 kHz and 2 kHz. Both of these clock sources aresynchronized to the main system AHB bus clock.

时钟资源是508KHZ和2KHZ，这两个时钟资源都与主要系统AHB总线时钟同步。

Clock recovery is the key for synchronization of MPEG-2 transportation over network. The PCR delay jitter is the main issue for clock recovery by PLL system.

时钟恢复是MPEG—2在网络上传输的同步关键，MPEG—2的标准建议采用PLL在本地恢复编码器的时钟，而PCR传输延迟抖动是PLL进行时钟恢复的主要问题。

When metastability occurs the clock-to-out time can be extended beyond the register's nominal tCO time. The additional time beyond the tCO time for the output signal to settle to a known state is known as the settling time. The tMET of a synchronization register chain is the sum of all output slacks of the registers in the chain.

对于这段话，我的理解是： tMET 时间和 tCO 时间之和就是异步时钟域的亚稳态时间，如果这个时间大于目的时钟域的同步寄存器链的时序余量（大概是时钟周期减去它的建立时间和保持时间之和吧），那么这时候系统采到的信号一定是亚稳态。

Given multi-clock domain systems integrated in the single chip,the number of asynchronous greatly increased, the metastability has increasingly important effects on the reliability of the PLDs.

在用P L D实现同步数字系统设计时，如果所有模块共用同一个时钟信号，系统中所有的寄存器都由该时钟的边沿来触发，这样的时钟设计·2006第02期·ELECTRONICS QUALITY可以使整个设计流程易于处理，顺利实现综合、布局布线到静态时序分析。

One difficulty of multiplexer implementation is how to deal with PCR in transport stream.

由于节目参考时钟是编解码器中共同系统时钟的标签，精确度要求非常严格，因此复用器研制的一个难点就是节目参考时钟的处理。

According to the chicking equipment for volt-monitor need to build up a standard clock,in order to achieve the request that the instrument carry on time accurate checking to the volt-monitor,this text introduced principle of the oscular clock chip PCF8583 with I2C bus,put forward to make use of the DS32KHz to provide the high stable frequency signal for PCF8583, thus carried out the project of the standard clock, and the interface design of PCF8583 with MCS51 is presented.

根据电压监测仪校验装置需要建立一个标准时钟，对电压监测统计仪进行时间精度校正的要求，介绍了I2C总线接口时钟芯片PCF8583的基本原理，提出了利用DS32KHz给PCF8583提供高稳定度频率信号，从而实现了标准时钟的方案，并给出了PCF8583与MCS51单片机接口设计。

Second, the instructions 1, remote control buttons: 0-9 keys, the red button to reset button,"SET" button to SET for the end,""," CLEAR "key to remove key,"▲"as is"▼ timer starts,"for the countdown began," on "and" pause key for ∨"to" TIME ","MODE" button, the clock display keys,"the timing for 1" for 12 hours system clock,"2" for 24 hours system clock.

二、使用说明 1、遥控器按键说明：0-9数字键、红色键为复位键，"SET"为设置键，""为结束键，"CLEAR"为清除键，"▲"为正计时开始键，"▼"为倒计时开始键，"∧"为暂停键，"∨"为继续键，"TIME"为时钟键，"MODE"为计时显示键，"1*"为时钟12小时制键，"2*"为时钟24小时制键。

A DPC ( 300 ) includes: a frequency source ( 310 ) for generating a clock signal; a delay line ( 320 ) for receiving the clock signal and generating phase-shifted clock signals at output taps; a digital control device ( 330 ) for generating a control signal; and a windowing and selection circuit for generating the output signal, that includes sequential logic devices ( 500, 510, 520 ) and a combining network.

DPC(300)包括：频率源(310)，用于产生时钟信号；延迟线(320)，用于接收时钟信号并在输出抽头产生相移时钟信号；数字控制器件(330)，用于产生控制信号；以及开窗口与选择电路，用于产生输出信号，包括：时序逻辑器件(500、510、520)和组合网络。

In clock routing,clock signal and clock skew become more and more important for impact of the circuit performance.

在时钟布线中，时钟信号和时钟偏差对电路性能的影响越来越明显。

The invention can regenerate irregular frame synchronous clock, and obtain regenerated bit clock synchronical to the regenerated frame synchronous clock.

利用本发明的方法和系统，可高质量地再生不规则的帧同步时钟，并可获得与再生帧同步时钟完全同步的再生位时钟。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。