倒计时牌
2024版多种倒计时器集锦PPT课件
智能手机倒计时器
利用智能手机内置的计时功能， 具有便携、易操作等优点，适用 于个人日常使用。
专业倒计时器
针对特定领域和需求设计，如体 育比赛、实验室研究等，具有高 精度、高可靠性、专业定制等特
点。 6
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CATALOGUE
日常生活倒计时器应用
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厨房烹饪计时
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计时功能
设定烹饪时间，确保食材 烹饪至最佳口感。
活动安排计时
为各类活动提供计时服务，如演唱会、展览、会议等，确保活动准 时开始和结束。
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CATALOGUE
创意个性化倒计时器设计
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自定义界面风格
提供多种主题和背景 选择，满足不同用户 的审美需求。
可调整界面布局和元 素大小，使界面更加 清晰易读。
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支持自定义背景图片， 让倒计时器更具个性 化。
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工作任务进度跟踪
设定任务时间
根据任务的紧急程度和重要性， 设定合理的完成时间。
制定任务清单
将工作任务按照优先级进行排序， 列出清单，明确每项任务的完成
时间和责任人。
进度监控
实时跟踪任务进度，确保按计划 进行，及时发现问题并调整。
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时间管理提高效率
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时间段划分
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支持在社交媒体上发布倒计时 器的状态和进度，增加社交互 动。
可与其他用户共享倒计时器， 实现多人协作和共同监督。
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THANKS
感谢观看
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23实现Βιβλιοθήκη 式可以采用硬件电路、单片机、PLC等不 同的实现方式，具体取决于应用场景和 需求。
24秒倒计时牌
1 设计任务描述1.1设计题目：24秒倒计时牌1.2设计要求1.2.1 设计目的(1)掌握24秒倒计时牌的组装方法与技巧；(2)掌握元器件的实现功能与使用；(3)能够通过对元器件组装来实现各种功能的电路；1.2.2 基本要求(1)可手动暂停,还原；(2)到0时有长报警,到倒数5秒时每秒有一声短报警；(3)可显示计数，每过十秒有一次闪烁；1.2.3 发挥部分(1)24秒可调；2 设计思路24秒倒计时器牌的核心部分是倒计时部分，我选择了两个74HC290连级来实现，因为它有置数端和预置端，可完成可调的倒计时器。
本次设计有基本要求：可手动暂停、还原；每十秒显示器闪烁一次；到倒数5秒时每秒有一声短报警，到0秒时是长报警，发挥部分是24秒可调。
首先是要给计时器提供一个秒脉冲发生器，由于555定时器内部的比较器灵敏度非常高，输出驱动电流大，功能灵活，而且采用差分电路形式，用555定时器组成的多谐振荡器的振荡频率手电源电压和温度变化的影响很小，因此采用555定时器来提供发生脉冲。
手动暂停还原中，由于需要暂时锁住显示器显示的数，所以可以在秒脉冲的输出端加一个开关，当要计数时关闭开关进行计数，需要暂停时断开开关终止秒脉冲的输入，即可实现手动暂停还原此时显示器保持原来的数字。
每十秒显示器闪烁一次，若想有闪烁效果需要给需要给显示器提供5~10赫兹的脉冲信号才能有闪烁效果，只要当个位为“0000”时闪烁即为每十秒闪烁一次，通过各种门电路把“0000”的信号与5~10赫兹的脉冲信号共同作用提供给显示器。
到5秒时开始每秒都有一次短报警，到0秒时是长报警，则十位输出是“0000”，5秒时个位的最高位也为零，使个位输出“101”、“100”、“011”、“010”、“001”时有效列真值表，通过门来连接；当为“000”时，为长报警。
给短报警一个500赫兹的脉冲信号，给长报警一个1000赫兹的脉冲信号，再通过一个或门来控制输出那个报警信号提供给报警电路。
关于安装高考倒计时牌的英语作文
关于安装高考倒计时牌的英语作文The college entrance examination, often referred to as the "Gaokao" in China, holds significant importance in the lives of millions of students and their families. As the date approaches, anticipation builds, dreams are curated, and the pressure intensifies. In this context, the installation of a countdown clock to mark the remaining days before the exam has become a common practice in many schools.To begin with, the significance of the countdown clock cannot be overstated. For many students, it serves as a tangible reminder of the time they have left to prepare. Every tick of the clock symbolizes an opportunity lost or gained, motivating students to maximize their study efforts. The visual representation of the countdown creates a sense of urgency that can encourage diligent work habits and foster a disciplined approach to preparation.Furthermore, the installation of the countdown clock acts as a source of motivation not only for students but also for teachers and parents. As the clock counts down, educators are reminded of the responsibility they carry in guiding their students toward success. The shared goal of performing wellin the exam solidifies the bond between educators and students, creating an environment of mutual support. Parents, too, find themselves drawn into the experience, often sharing long hours of study with their children, thus reinforcing familial ties during this critical period.However, the presence of such a clock is not without its drawbacks. The pressure it generates can lead to anxiety among students. With every passing day, the emotional weight can sometimes overshadow the joy of learning, transforming a life-changing examination into a source of overwhelming stress. It is essential for schools to approach the installation of the countdown clock with mindfulness,ensuring that it serves as a tool for motivation rather thana harbinger of anxiety.To alleviate potential stress, schools can accompany the countdown clock with supportive initiatives. For instance, workshops focused on stress management, time management, and effective study techniques can be introduced. By equipping students with coping strategies, educators can help foster an environment where the countdown serves as a positive, motivating factor rather than a source of dread.In conclusion, the installation of a countdown clock for the college entrance examination plays a multifaceted role in shaping the experiences of students, teachers, and parents alike. While it can act as a powerful motivator, it is imperative to balance this with support systems thatalleviate anxiety. By creating a holistic environment that emphasizes preparation while also nurturing mental well-being, schools can ensure that the countdown clock stands as asymbol of hope and determination rather than fear. In doing so, it can inspire a generation of students to face their future with confidence and resilience.。
超市开业倒计时表(最新)
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理货员、收银员、信息录入员到位，并对所 有员工进行岗前培训
14 完场电脑POS机MIS系统的安装调试
15
进行卖场内装顶、地、墙、上下水、排烟、 灯带安装）
→★
→★ →★ →★
→★
★
★
16
外租区各专柜装修全部到位，货架进场并安 装到位
17
对招商工作进行总结，对缺项品类进行补 充，进行招商的扫尾工作
训，பைடு நூலகம்时防损人员到位
6
人事部安排所有人员进行考核，确定最终上 岗人员，分配到岗
★ →→★
★
7 超市的软件应用系统安装完毕
→★
8 超市开始进行合同文本录入及商品信息录入
→★
9 超市货架及库房货架陆续到位并进行安装
10
收货设备到位（包括栈板、手动叉车、条码 机）
11 冷库的厂家确定并安装
12 制冷设备进场安装调试（冷冻，冷藏设备）
18 各部门上报需预付款的厂家
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采购部各部门向供应商下订单，各部门理货 员作好商品配置，作好接货各项准备
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业务开始开业促销品洽谈并签订促销协议 书：店内开始吊旗设计印制
21 企划部海报拍照设计制作印刷
22 现场管理部门员工进场打扫卫生
5.1 5
23 商品陆续到位
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企划部作出各种店堂布置、设计方案，确定 开业促销海报，作出开业礼品发放计划
物，凭票入场？）
37 根据试营业中出现的各种情况进行整改总结
★
38 各部门进行商品补货
★
39 员工进行营业前促销海报的发放
★
40
正式开业 7：20员工到场，进行开业前最后 准备工作，保安做好现场安全保卫
简单实用的高精度倒计时牌设计
Ａ ８Ｃ １ Ｔ ９ ５ 型单 片机 是 整 个 控 制 系统 的 核 心 。 可 用 于 完 成 对 串 行 口控 制 器 的初 始 化 和 数 据 读 写 ，此 外 。还要 对接 收 的各种 数据 进 行识 别 、转 储及 显示 。 由于 日本 光 电公 司 的Ｇ Ｖ一 ５ Ｏ Ｍ Ｇ Ｓ Ｓ １ 型 Ｅ Ｐ 接
可 在 上 升 沿 锁 存 数 据 ；８ （ ）为３ 输 出控 制 脚 Ｅ 态
端 。该脚 接低 电平 时可 输 出数 据 。
利用 单 片机 输 出的数 据 和移 位 时钟 ．可 在 时 钟 上 升 沿将 数 据 移 入７ Ｈ ５ ５ １ 用 于 输 出数 ４ Ｃ ９ 。Ｐ ． ０ 据 ．可 在 移 位 脉 冲 上 升 沿 到 来 时 将 数 据 移 出 。 Ｐ ．输 出移 位脉 冲 。Ｐ ．输 出 锁存 脉 冲 。在并 行 １１ １ ２ 输 出 端 上 经７ Ｈ ０ 驱 动 数 码 管 显 示 。 由 于数 据 ４ Ｃ７
机 的串 口输入 输 出格式 匹 配 ．所 以可利 用单 片 机 串行 口直接从 Ｏ Ｍ接收数 据 。 Ｅ
Ｄ １Ｃ ８ 具 有 提 供 较 高 精 度 年 、 月 、 日 、 Ｓ２ ８７ 时 、分 、秒 时 间 的功能 ，对 其进 行校 准后 ，可在 掉 电情 况下 。１ 年 之 内仍 能 准确 地进 行计 时 ，并 Ｏ
ｗｌ ｅｄ．ｎ ２０ ． 电 子 元 器 件 主 用 ｔ ｃｔ ， ０ ７８ ， ￣． １ ｃ ４ ５
收 板 传 输 的数 据 是 以 串行 方 式 输 出 的一 — ２ ２０ — ５ ２
维普资讯
第９ 卷
了其硬 件控 制 电路 和软件 程序 框 图。 ．
关键词 ：Ｇ Ｓ Ｐ ；卫 星导航 ；高精 度 ；倒计 时牌
教室安装高考倒计时牌的英语作文
教室安装高考倒计时牌的英语作文全文共10篇示例，供读者参考篇1As a primary school student, I want to talk about the installation of a countdown clock in the classroom for the high school entrance exam.Hey everyone, do you remember when we were in primary school and our teachers would put up a countdown clock for our exams? Well, now that we are older and getting ready for the big high school entrance exam, our teachers have put up a countdown clock in our classroom too!It's so cool to see the days, hours, minutes and seconds ticking away until the exam. It helps us stay focused and motivated to study hard every day. Sometimes it can be a bit scary to see how little time we have left, but it also gives us a sense of urgency to make the most of every moment.The countdown clock also helps us organize our time better. We can plan out our study schedule and make sure we cover all the topics before the exam. It's like a little reminder that we should be working hard and not wasting any time.I think it's a great idea to have the countdown clock in our classroom. It's a visual representation of our goal and reminds us that the exam is coming soon. It's like a little push to keep us going and do our best.So, let's all work hard and make the most of the time we have left before the high school entrance exam. We can do it!篇2Hey guys, do you know what time it is? It's almost time for the big test - the college entrance examination! Our school just installed countdown clocks in the classroom to remind us how many days are left until the exam.I think it's a great idea because now we can all see how much time we have left to study and prepare. It's like a constant reminder to stay focused and work hard. And it's also a little exciting to see the numbers ticking down each day.Some of my classmates were a little nervous when they saw the countdown clocks for the first time. But I think it's important to stay positive and keep a good attitude. We've been working hard all year and we just need to keep pushing ourselves until the exam day.I like to use the countdown clock as motivation. Every time I see it, I tell myself that I can do it, and that all this hard work will pay off in the end. I know that I've prepared as best as I can, and now all I can do is give it my all.So let's all support each other and keep pushing ourselves until the exam day. We've got this, guys! Let's show everyone what we're capable of. Good luck to all of us!篇3Title: Installing the High School Entrance Examination Countdown Clock in the ClassroomHey everyone! Today I want to talk about something super exciting that happened in our classroom. We got a new countdown clock installed and do you know what it's for? It's for the High School Entrance Examination!So, the other day our teacher told us that there are only 100 days left until the big exam. We were all so shocked because it feels like just yesterday we were starting primary school. Time really flies, doesn't it?The countdown clock is really cool. It's big and bright and right at the front of the classroom where we can all see it. Everymorning, when we come in, we all gather around it to see how many days are left. It's like a fun little daily reminder to keep studying hard and doing our best.I think having the countdown clock is a great idea because it motivates us to work harder and stay focused. We all want to do well on the exam and get into a good high school, so seeing the countdown every day really helps us stay on track.I can't wait to see the numbers keep getting smaller and smaller as we get closer to the exam date. It's going to be such an exciting day when we finally reach zero and get to show off all the hard work we've put in.I hope the countdown clock helps all of us do our best and achieve our goals. Let's keep pushing ourselves and supporting each other along the way. We can do it!That's all for now. See you next time!篇4Hello everyone! Today I want to talk about something cool that happened in our classroom recently. Our teacher installed a countdown clock for the upcoming high school entrance exam!It's super exciting because now we can see exactly how many days, hours, and minutes are left until the big day. It's like a constant reminder that we need to keep studying hard and doing our best to prepare for the exam.The clock is big and bright, with numbers that change every second. It's right up at the front of the classroom where everyone can see it without even having to squint. And let me tell you, it's been a real motivation booster for all of us.Every morning when we walk into class, the first thing we do is check the countdown clock. It's like a little competition to see who can get the closest guess to how many days are left. And then throughout the day, we all sneak glances at it to remind ourselves of the hard work we need to put in.I think having the countdown clock in our classroom is a great idea. It keeps us focused, motivated, and excited for the challenge ahead. I know we're all going to do our best on the exam, thanks in part to that little clock ticking away at the front of the room.So, here's to studying hard, staying focused, and making the most of the time we have left before the big day. Let's do this, everyone!篇5Title: The Installation of the High School Entrance Exam Countdown Clock in the ClassroomHey guys, have you noticed something new in our classroom? Yes, that's right – we have a brand new countdown clock installed on the wall! Do you know what it's for? It's for counting down the days until the high school entrance exam!I think it's so cool to have the countdown clock in our classroom. It's like a little reminder every day that the exam is coming up soon. It makes me feel motivated to study hard and do my best on the test.The countdown clock is not only helpful for us students, but also for our teachers. They can use it to plan their lessons and make sure we cover all the topics before the exam. They can also use it to remind us of important dates and deadlines leading up to the test.I also like how the countdown clock adds a new element to our classroom. It's like a decoration that serves a purpose. It makes our classroom feel more exciting and focused on our goals.Overall, I think the installation of the high school entrance exam countdown clock in our classroom is a great idea. It keeps us motivated, helps our teachers plan, and adds a fun element to our learning environment. I can't wait to see how many days are left until the exam – let's work hard and do our best, everyone!篇6Title: Installing a Countdown Clock for the College Entrance Examination in the ClassroomHello everyone! Today, I want to talk about something super exciting that happened in our classroom - we got a countdown clock for the college entrance examination! It's like a super cool clock that shows us how many days are left until the big exam. Isn't that awesome?At first, we were all wondering why our teacher wanted to put up a countdown clock in the classroom. But then she explained that it would help us stay focused and motivated as we prepare for the exam. Plus, it's a fun way to keep track of how much time we have left to study.Every morning when we come into class, we all look at the countdown clock and see how many days are left. It's a little bit scary to see the number getting smaller and smaller, but it alsoreminds us that we need to work hard and make the most of our time.Our teacher also created a little chart next to the countdown clock where we can write down our study goals for the day. It's like a mini to-do list that helps us stay organized and on track. And every time we finish a task, we get to check it off the list - it's so satisfying!I think having the countdown clock in our classroom is a great idea. It's a visual reminder of the big goal we're working towards, and it's a fun way to stay motivated. I can't wait to see how many days are left tomorrow! Let's keep working hard and do our best on the college entrance examination. Go team!篇7In our classroom, we have a big countdown clock hanging on the wall. It's called the "High School Entrance Exam Countdown Clock". Every day, we look at it to see how many days are left until the big exam.The countdown clock is really helpful because it reminds us that the exam is coming soon and we need to study hard. It's like a big alarm clock that keeps us on track and focused on our goals.When there are 100 days left, we all cheered and clapped our hands. We knew we had to work hard to prepare for the exam. Some of us started joining study groups, while others made flashcards and study guides.As the days passed by, the numbers on the countdown clock decreased. We could feel the pressure building up, but we didn't give up. We knew that all our hard work would pay off in the end.Finally, the day of the exam arrived. We sat in our desks, feeling nervous but also confident. Thanks to the countdown clock, we were well-prepared and ready to do our best.After the exam was over, we all gathered around the countdown clock one last time. It now showed a big "0". We had made it! We had survived the High School Entrance Exam.The countdown clock may have been just a simple decoration in our classroom, but it played a big role in our journey to the exam. We will always remember the days we spent watching the numbers tick down, knowing that we were one step closer to achieving our dreams.篇8As a primary school student, I am very excited to share with you about the installation of the countdown clock for the college entrance examination in our classroom.So, a few days ago, our teacher told us that we will have a special clock in the classroom. This clock is called the countdown clock for the college entrance examination. It is to remind us that the big test is coming soon and we need to study hard to get good grades.When the clock was put up in the classroom, all of us were so excited! We all gathered around the clock and looked at the numbers ticking away. It made us feel a little nervous, but also motivated us to work harder.Every day, we would look at the clock and see how many days were left until the exam. It was like a little reminder to us that time was running out and we needed to make the most of it. Some of my classmates even made a study schedule based on the countdown clock.I think having the countdown clock in our classroom is a great idea. It helps us stay focused and motivated to study. I hope that when the big day finally arrives, we will all be ready and do our best on the exam.In conclusion, the countdown clock for the college entrance examination is a helpful tool for us students. It reminds us of the importance of the exam and encourages us to work hard. I am grateful to have it in our classroom and I believe it will help us achieve our goals. Let's study hard and do our best!篇9Title: Installing the Countdown Clock for the College Entrance Examination in the ClassroomHey guys, have you noticed something new in our classroom recently? That's right! We have installed a cool countdown clock for the college entrance examination!It all started when our teacher told us that the college entrance examination is coming soon. We all felt a little nervous and anxious because it's a big test that will determine our future. So, our teacher came up with the idea of installing a countdown clock in the classroom to help us keep track of the days left before the exam.We were all excited about the idea and couldn't wait to see the countdown clock. When it was finally installed, we gathered around it and admired how cool it looked. It had big, boldnumbers that showed us exactly how many days, hours, minutes, and seconds were left before the exam.Every day, we would gather around the countdown clock and cheer each other on. We would encourage each other to study hard, stay focused, and believe in ourselves. It was like a little reminder that we were all in this together and that we could support each other through this challenging time.Thanks to the countdown clock, we became more motivated and determined to do our best in the college entrance examination. We knew that the days were ticking away, but we were ready to face the challenge head-on.So, if you ever feel stressed or worried about the college entrance examination, just look at the countdown clock in our classroom. It will remind you that you're not alone, and we're all in this together. Stay positive, stay focused, and believe in yourself. We got this!篇10Title: Countdown Clock Installation in the ClassroomHey guys, have you noticed something new in our classroom? Yes, that's right! We have a cool new countdown clock installedon the wall. Do you know what it's for? It's for counting down to the high school entrance exam, also known as the gaokao!The gaokao is a super important exam for all of us because it determines which college we can go to in the future. That's why our teacher decided to install this countdown clock to remind us how much time we have left to study and prepare for the exam.Every day, when we walk into the classroom, the first thing we do is check the countdown clock. It shows us exactly how many days, hours, and minutes are left until the gaokao. It's kind of scary to see the days ticking by so quickly, but it also motivates us to work harder and make the most of our time.Some of us have even started making study schedules and planning out our revision timetables. We know that every minute counts, so we're trying our best to stay focused and dedicated to our studies.So, let's all work together and support each other as we countdown to the gaokao. We can do this, guys! Let's study hard, stay positive, and give it our all. Good luck to all of us!That's all for now. See you in the next class!。
分钟倒计时九分八分五分
八分钟内可能发生的变化和事件
完成一个小任务
在八分钟内，你可能完成 一个简单的小任务，如填 写一份表格、回复一封电 子邮件等。
开始一个大项目
通过八分钟的热身，你可 能对一个新项目有了初步 的想法或计划，为后续工 作打下基础。
沟通与协作
在八分钟内，你可以与同 事或客户进行简短的沟通， 明确工作方向或解决一些 问题。
分钟倒计时九分八分五分
• 引言 • 分钟倒计时九分 • 分钟倒计时八分 • 分钟倒计时五分 • 总结
01
引言
目的和背景
目的
通过倒计时的方式，帮助人们更好地 管理时间，提高效率，特别是在需要 集中注意力或时间紧迫的情况下。
背景
随着现代生活节奏的加快，人们对时 间管理的需求越来越高，倒计时成为 一种有效的工具，广泛应用于各种场 景，如考试、比赛、会议、烹饪等。
反思如何改进和提高效率。
五分钟内可能发生的变化和事件
快速回复
在五分钟内回复一封重要的邮件，有助于及 时沟通和解决问题。
整理桌面
五分钟内清理工作区域，创造整洁有序的工 作环境。
短暂休息
利用五分钟时间进行深呼吸、伸展等放松活 动，缓解紧张情绪和疲劳感。
快速学习
五分钟内阅读一篇文章或学习一个新知识点， 积少成多，逐步提升个人能力。
如何有效利用这九分钟
制定计划
在倒计时开始之前，明确九分钟内要完成的任务和目标。 制定详细的计划，包括时间分配、任务优先级和具体步骤 。
合理安排时间
根据任务的紧急性和重要性，合理安排时间。对于需要长 时间完成的任务，可以考虑拆分成更小的步骤，以便更好 地管理时间。
集中注意力
为了充分利用这九分钟，需要集中注意力，避免被外界干 扰或分散精力。通过专注于当前任务，可以提高效率并减 少时间浪费。
初三毕业班教室布置标语
初三毕业班教室布置标语
一、制作主标语：（位置：前/后墙黑板上面尺寸：）
人因梦想而伟大，人因行动而成功！（前）
插上理想的翅膀，扬起青春的风帆（后）
二、制作副标语：（位置：教室后墙右尺寸：）
人生最大的对手是自己，
自己最大的对手是懒惰，
战胜对手，战胜自己，战胜懒惰！
三、中考倒计时牌：
光阴易逝，岂容我待？离中考仅有天
四、教室前面墙上左侧张贴：
张贴栏
五、目标制定：(位置：教室左面上张贴尺寸： )
我的绚丽人生从这里起步！
人生的第一次选择，我选择奋斗！对自己负责，向自己承诺，为自己喝彩！
伟大的目标只有经过忘我的斗争和牺牲才能胜利实现。
我努力，我一定可以成功！
学生的理想
图书角
六、班级誓言：教室右墙
扬帆把舵奋勇拼搏
---2013级1班班级誓言
一班的学子是勤奋的，是聪颖的，
我们自信开朗、奋发向上；
我们信心百倍、干劲十足！
一班的勇士们，
来，让我们携起手，喊出我们的激情！永争第一不畏坚
奋力拼搏永向前
艰难困苦斗志昂
齐心协力创辉煌。
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3、设计原理
利用定时器8253、8255和8259以及键盘和数码显示电路，设计一个倒计时牌，由8253中断定时，小键盘控制倒计时牌的启停及初始值的预置。
在此系统中，8253的功能是定时，接入8253的CLK信号为周期性时钟信号。8253采用计数器0，工作于方式2，使8253的OUT0端输出周期性的负脉冲信号。即每隔1min，8253的OUT0端就会输出一个负脉冲的信号，此信号接8259的IR2，当中断到60次数后，CPU即处理，使液晶显示器上的时间发生变化。其中8259只需初始化ICW1，其功能是向8259表明IRx输入是电瓶触发方式还是上升沿触发方式，是单片8259还是多片8259。8259接收到信号后，产生中断信号送CPU处理。
（2）8253的功能用途是：
1、延时中断
2、可编程频率发生器
3、事件计数器
4、二进倍频器
5、实时时钟
6、数字单稳
7、复杂的电机控制器
（3）8253有六种工作方式：
1、方式0：计数结束中断
2、方式1：可编程频率发生器
3、方式2：频率发生器
4、方式3：方波频率发生器 图6 8253引脚图
5、方式4：软件触发的选通信号
2、设计参考
本程序中有几个要点：
（1）设计一个1s时钟，作为时间的基准。可通过定时器来实现，由于定时限制，我们可以设定定时时钟为50ms中断一次，然后用一个计数器计数20次。
（2）由于实际应用中要求显示为十进制数，而在程序中处理的数据都为十六进制，因此在程序中要对显示缓冲区的数据进行十进制调整。
（3）在设计时，LED显示应1秒跳动一次。
PA7~PA0——A口外设双向数据线；
PB7~PB0——B口外设双向数据线；
PC7~PC0——C口外设双向数据线；
RESET——复位输入信号
（3）8255端口地址
信号线
寄存器
编址
IOY3
A口
60H
B口
61H
C口
62H
控制寄存器
63H
3、8259芯片
（1）内部结构及引脚
中断控制器8259A是Intel公司专为控制优先级中断而设计开发的芯片。它将中断源优先排队、辨别中断源以及提供中断矢量的电路集中于一片中。因此无需附加任何电路，只需对8259A编程，就可以管理8级中断，并选择优先模式和中断请求方式，即中断结构可以由用户编程来设定。在MD微机系统中，8259芯片工作于单片方式。
6、电路图
图1总电路图
图2显示模块和声光报警模块电路
图3小键盘模块电路
图4 定时模块和中断处理模块电路
图5 声光报警模块电路
。
第三章 设计所用芯片简介
一、设计所用设备
8253定时器：用于产生秒脉冲，其输出信号可作为中断请示信号送IRQ2。
8255并行接口：用做接口芯片，和小键盘相连。
8259中断控制器：用于产生中断。
心得与体会……………………………………………………………37
评语 …………………………………………………………………39
第一章设计简介
1、设计思想概述
本系统设计以8086微处理器作为CPU，用8253做定时计数器产生时钟脉冲，8255做可编程并行接口显示时钟和键盘电路，8259做中断控制器产生中断，接LED显示倒计时天数以及小时、分钟、秒（各2位）和扩展调整键盘。
8086CPU：作为微处理器。
LED：八个LED灯用于显示天、时、分、秒倒计时牌。
发光二极管、小喇叭：用于实现声光报警。
小键盘：用16键控制设置。
二、设计所用芯片结构
1、8253芯片
（1）内部结构及引脚
8253可编程定时/计数器是Intel公司生产的通用外围芯片之一，有3个独立的十六位计数器，技术频率范围为0~2MHZ，它所有的技术方式和操作方式都通过编程控制。
4、倒计时的硬件框图
框图如下：
第二章 详细设计
系统分为5个功能模块，分别为：主程序模块，定时模块，中断模块，小键盘控制模块，LED显示模块。
1、主程序模块
主控模块是其心模块，对8253、8255和8259进行初始化，设置中断向量，扫描键盘根据按键值作相应的处理。主要由软件实现。它的主要功能是调用其它模块对系统工作进行协调，读小键盘输入键值并执行要做的工作。
2 设计参考……………………………………………………………6
3 设计原理……………………………………………………………6
4、倒计时的硬件框图…………………………………………………7
第二章 详细设计……………………………………………………8
1、主程序模块…………………………………………………………8
2、定时模块……………………………………………………………8
方式0—基本输入/输出方式
方式1—选通输入/输出方式
方式2—双向选通输入/输出方式
（2）8255引脚图如图3.2示，各引脚功能如下。
D7~D0——与CPU侧连接的八条双向数据线；
WR（低电平有效）——写输入信号；
RD（低电平有效）——读输入信号；
CS（低电平有效）——片选输入信号；
A0、A1——片内寄存器选择输入信号；
《计算机原理及接口技术》
课程设计报告
题目
学院
专业
班级
学生姓名
学号
2011年12月19日至12月30日共2周
指导教师
课程设计任务书
一、设计目的
1、培养学生综合运用所学知识的能力，提高学生解决实际问题的能力;
2、培养学生查阅资料，使用工程设计标准、手册及编写设计技术的能力;
3、培养学生初步掌握设计开发产品的能力，了解微机控制系统的一般设计方法;
中断序号
01Biblioteka 2345
6
7
功能调用
08H
09H
0AH
0BH
0CH
0DH
0EH
0FH
矢量地址
20H
~
23H
24H
~
27H
28H
~
2BH
2CH
~
2FH
30H
~
33H
34H
~
37H
38H
~
3BH
3CH
~
3FH
说明
时钟
键盘
可用
可用
串行口
可用
可用
可用
4、8086CPU
8086微处理器的主要特点：8086为16位微处理器，数据总线16位，地址总线20位，可寻址1MB存储空间，时钟频率为5～10MHz。8086 CPU的内部结构由执行单元EU（execution unit）和总线接口部件BIU（bus interface unit）两部分组成。
SP/EN——从编程/允许级联。在缓冲方式中，可用做输出信号以控制总线缓冲器的接收和发送。在非缓冲方式中，作为输入信号用于表示主片还是从片；
IR0~IR7——外部中断请求输入线。要求输入的中断请求信号是由低电平到高电平的上升沿（并保持高电平到CPU响应时为止）或者是高电平。
（2）8259中断矢量地址与中断信号之间的关系如表3所示：
8086COU外部引脚图如图所示。 图9 8086CPU外部引脚图
AD7~AD0——八条地址/数据复用线；
A15~A8——单一的地址线；
SS0——状态信号线。该引脚在最大工作方式下保持高电平，在最小方式下等效于最大方式下S0的作用，它与IO/M、DT/R组合以确定当前的总线周期；
A19/S6~A16/S3——地址/状态总线；
8259引脚图如图3.3，各引脚功能如下。
D7~D0——八条双向数据线； 图8259引脚图
WR（低电平有效）——写输入信号； A0——地址信号；
RD（低电平有效）——读输入信号；
CS（低电平有效）——片选输入信号；
INTA（低电平有效）——中断响应信号；
CAS0~CAS2——级联信号，形成一条专用8259A总线，以便多片8259A的级联；
3、中断处理模块………………………………………………………8
4、小键盘模块…………………………………………………………8
5、LED显示模块………………………………………………………9
6、电路图……………………………………………………………9
第三章 设计所用芯片简介…………………………………………12
4、小键盘模块
小键盘模块送入主控模块的子功能模块。由软件和硬件实现，硬件上由小键盘和8255互连，将小键值由8255送入主控模块。软件上使用行扫描法获得键值并送回主控模块。本课题只考虑去抖动。执行一个约10ms的延时程序后再扫描键盘，若F0=1表示真正有键按下，从而消除了抖动影响。
5、LED显示模块
2、定时模块
定时模块是为8259提供中断请求信号的。由一片8253实现，选用定时器0，工作在方式2，显示应1秒跳动一次，其输出信号可作为8259的中断请求信号。
3、中断处理模块
中断模块实现动态显示的，硬件为一片8259，由于中断请求信号为每1秒一次，中断程序该为时间按秒增加，并显示，只要开中断，便可实现每过1秒秒显示减一，从而达到动态显示的效果。
GATE——选通输入（门控输入），用于启动或禁止计数器的操作，以使计数器和计测对象同步。
（5）8253端口地址
信号线
寄存器
编址
IOY2
0#计数器
40H
1#计数器
41H
2#计数器
42H
控制寄存器
43H
2、8255芯片
（1）内部结构及引脚
8255可编程外围接口芯片是Intel公司生产的通用并行I/O接口芯片，它具有A、B、C三个并行接口，用+5V单电源供电，能在以下三种工作方式下工作：