Grammar(基本语法)
Grammar
1st basic sentence pattern
Everybody laughed.
People suffered.
The sun sets in the west.
Google becomes one of the most admired companies.
Ipad2 looks gorgeous!
My face turned red.
They fall in love.
常见系动词：look, seem, appear, sound, feel, taste, smell, grow, get, fall (ill/asleep), stand/sit (still), become, turn等Tips：
of + 名词
It is of + 名词，意思等同于it is + 该名词的形容词形式，是很地道的说法。
例：This book is of great help to me. 这本书对我很有帮助。= This book is greatly helpful to me.
Oil hits its highest price since September 2008.
Premier Wen Jiabao made a report on the work of the government.
Beijing impose d house purchase restriction policy.
常见动词总结：
pass, give, show, tell, lend, take (to)
buy, cook, get, sing, make (for)
I gave him my address.
Give me your bank card. => Give your bank card to me.
buy me a big house. . => Buy a big house for me. to 表示动作方向或for 表示动作目标
I found the box empty.
On Facebook, How to Keep Your Group Secret
The Technology Made Mobile Payments a Reality
I find it sensible 【that you are participating in the South Stream project】.
常见动词：make, keep, find, see, leave
注意：感官动词（see hear notice watch feel observe）后跟宾补，有两种形式。
动词不定式：某一次的，具体的；现在分词：经常的，反复的
I hear somebody singing somewhere.
I often hear him sing in the next room.
2nd simple sentence
1. 主语+谓语
主语+不及物动词：They are dancing.
2.主语+系动词+表语
系动词be：We are students.
系动词为turn, get, become, look：
Things become complicated.
The leaves are turning yellow.
3. 主语+谓语+宾语
主语+及物动词+宾语：He loves sports.
主语+不及物动词+介词/副词+宾语：She picks up the coin.
主语+动词+to do作宾语：I prefer to take a walk.
主语+动词+doing作宾语：We like having a party.
3rd compound sentence
句子原则1：一个句子只能有一个谓语，谓语由动词构成。
句子原则2：如果一个句子有多个动词，只有一个是谓语动词，其他为非谓语动词。
When I woke up, I found my mother sitting beside me.
句子原则3：如果一个句子有多个谓语，那么这个句子可能是并列句或者是复合句。如果有并列连词，就是并列句，如果没有就是复合句。以上的原则对句子分析是很有帮助的，请熟记之。
1.转折对比
I hope you don't mind me asking, but where did you buy those shoes?
The car is old, yet it is in good condition.
I do every single bit of housework while my husband Bob just does the dishes now and then.
2.因果
I did my best not to show pleasure, but what I was feeling was pure happiness, for my words had the power to make people laugh.
The shop doesn't open until 11 a.m., so it loses a lot of business.
3.选择
Would you like a cup of coffee or shall we get down to business right away?
I'm lucky that I'm interested in school work, otherwise I'd go crazy.
Sightseeing is best done either by tour bus or by bicycles.
4.并列
Stand over there and you'll be able to see it better.
Not only I but also Jane and Mary are tired of having one examination after another.
They worked neither for fame nor for personal gains.
A man should have both courage and wisdom.
5.其他
It was not the bones of an animal but of a human being.
Rather than ride on a crowded bus, he always prefers to ride a bicycle.
Jasmine was holidaying with her family in a wildlife park when she was bitten on the leg by a lion.
4th complex sentence （clause）
Who will go to the conference is not important.
The question is whether we shall run out of food soon.
His mother who loved him very much died in 1818.
5th nominal clause
引导名词性从句的连接词可分为三类：
连接词：that, whether, if （不充当从句的任何成分）
连接代词：what, whatever, who, whoever, whom, whose, which
连接副词：when, where, how, why
不可省略的连词：
1. 介词后的连词
2. 引导主语从句和同位语从句的连词不可省略
That she was chosen made us very happy.
We heard the news that our team had won.
①That the driver could not control his car was obvious.
②That she was chosen made us very happy.
③That he will come is certain.
★it做形式主语，把从句置于句尾，此时that有时可省。
①It was obvious that the driver could not control his car.
②It made us very happy that she was chosen.
③It is certain that he will come.
如果以that从句为主语的句子是疑问句，就只能用先行词it结构。
①Is it certain that he will come?
②Is it true that he would take the risk?
★whether/if引导主语从句
Whether he will win the game is not clear.
Whether he will come is uncertain.
Whether she comes or not doesn't concern me.
It is not clear whether/if he will come.
It was uncertain whether he would come.
★what, who, which, whose, when, where, why, how引导主语从句What we need is more time.
Who was responsible for the accident is not yet clear.
Whose book it is not important.
Which school you want to go matters much.
Why he did this is not known.
When he will come is still unknown.
It is not known why he did this.
How he succeeded is unknown to us.
Where we should hold the meeting needs to be discussed.
Whatever he gave you should be handed in.
Whoever told you that was lying.
Whoever comes is welcome.
专项训练：
1.______ makes mistakes must correct them.
A. What
B. That
C. Whoever
D. Whatever
2. It worried her a bit ______ her hair was turning grey.
A. while
B. that
C. if
D. for
3.When and why he came here ______ yet.
A. is not known
B. are not known
C. has not known
D. have not known
4.______ is no reason for dismissing her.
A. Because she was a few minutes late
B. Owing to a few minutes late
C. The fact that she was a few minutes late
D. Being a few minutes late
5.______Tom liked to eat was different from ______.
A. That…that you had expected
B. What …that you had expected
C. That…what you had expected
D. What…what you had exp ected
6.______ we go swimming every day ______ us a lot of good.
A. If...do
B. That...do
C. If...does
D. That...does
7.It ______ Bob drives badly.
A. thinks that
B. is thought what
C. thought that
D. is thought that
8.It's uncertain ______ the experiment is worth doing.
A. if
B. that
C. whether
D. how
9.______ the boy didn't take medicine made his mother angry.
A. That
B. What
C. How
D. Which
10.______ we can't get seems better than ______ we have.
A.What, what
B. What, that
C. That, that
D. That, what
2._ object clause
置于动词、介词等词性后面起宾语作用的从句叫宾语从句。宾语从句的语序必须是陈述语序。谓语动词、介词、动词不定式，v.-ing形式后面都能带宾语从句。有些形容词（afraid,sure,glad等）之后也可以带宾语从句。
★that
I know (that) you have met him.
Let's suppose that one day this happens to you.
I don't think it will be very cold today.
I don't think you are right.
★if/whether
He asked if she would come.
I don't know whether to attend the meeting.
★what,who,whose,which,when,where,how,why
Tell me what you want.
He didn't know what time it was.
Whose book it is not important.
Please tell me which school you want to go.
★whatever,whoever,whenever,wherever
Please write down whatever he is saying.
I don't know whoever will come.
I'll do whatever you ask me to.
★表示爱憎情感的动词，如：enjoy, hate, love, like, dislike, don't mind, resent, appreciate（感激）等以及某些介词结尾的短语动词如：count on, depend on, rely on, see to, look forward to, be fond of, feel like, see to等后，即使没有宾补也要先接形式宾语it，再接宾语从句。
I like it when she smiles at me.
I love it when you sing.
I hate it if I am spoken to loudly in public.
专项训练：
1、Do you know how much hot water ______?
A.Mum is needed
B.does Mum need
C.Mum needs
D.did Mum need
2、Can you tell me ______?
A.where he is
B.where is he
C.he is where
D.what is he
3、I didn't know how ______ to London?
A.would they go
B.are they going
C.they would go
D.they are going
4、I want to know how long ______.
A.has he been back
B.has he come back
C.he has been back
D.he has come back
5、Do you know ______?
A.what the news are
B.what is the news
C.what the news is
D.what are the news
6、He said he would help me with my maths if he ______ free.
A.was
B.will be
C.would be
D.is
7、He will write to you as soon as he ______ to Shanghai.
A.gets
B.is getting
C.will get
D.shall get
8、Father ______ music when he ______ young
A.liked…was
B.liked…is
C.likes…was
D.likes…is
9、I liked sports ______ I was young.
A.so much as
B.so much that
C.very much when
D.very much because
10、______ mother got home,I was tidying my room.
A.After
B.When
C.As soon as
D.Before
3._predicative clause
表语从句就是用一个句子作为表语。说明主语是什么或者怎么样，由名词、形容词或相当于名词或形容词的词或短语充当，和连系动词一起构成谓语。
连接词有：that, what, who, when, where, which, why。
★that在引导表语从句时无含义，不作成分，通常不省。
1)表示事实、真理等的实际内容。
The fact is that he is lying.
The odds are that he will not do it.
2）表示某人的意见、信念等的实际内容。
Our belief is that things will improve.
The trouble is that we are short of money.
★whether引导表语从句（不可用if)。
His first question was whether Holmes had arrived yet.
The question is whether people will buy it.
★连接代词who, whom, whose, what, which引导的表语从句。
This is what I want.
The question is who can be chosen to be manager of the company.
My question is which of them is better.
★连接副词when, where, why, how引导的表语从句。
The problem seemed how we could make him understand it.
The question is where we should go.
★as if, as though引导的表语从句（常用虚拟语气）。
He looks as if he were angry.
It looks as if it's going to rain.
专项训练：
1. The question is ______ we will have our sports meet next week.
A. that
B. if
C. when
D. whether
2．The reason why he failed is ______ he was too careless.
A. because
B. that
C. for
D. because of
3. Go and get your coat. It's ______ you left it.
A. where
B. there
C. there where
D. where there
4．The problem is ______ to take the place of Ted
A. who can we get
B. what we can get
C. who we can get
D. that we can get
5. What I want to know is ______ he likes the gift given by us.
A. that
B. if
C. whether
D.不填
6. The reason is ______I missed the bus.
A. that
B. when
C. why
D. what
7. That is ______ we were late last time.
A. that
B. when
C. why
D. what
8. She looked ______ she were ten years younger.
A. that
B. like
C. as
D. as though
9.-- I fell sick!
-- I think it is ______ you are doing too much.
A. why
B. when
C. what
D. because
10. The reaso n why he hasn’t come is ______.
A. because his mothe r is ill
B. because of his mother’s being ill
C. that his mother is ill
D. for his mother is ill
11.-- He was born here.
-- That is ______ he likes the place so much.
A. that
B. what
C. why
D. how
12.That is ______ Lu Xun once lived.
A. what
B. where
C. that
D. why
4._appositive clause_
引导同位语从句的连接词
1.如同位语从句意义完整，应用that引导同位语从句。
He always works hard in spite of the fact that he is not in good health.
Suddenly the thought came to me that he would go blind.
2.如同位语从句意义不完整，需增加"是否"的含义，应用whether引导同位语从句。
We'll discuss the problem whether the sports meeting will be held on time.
3.如同位语从句意义不完整，需增加"时候"、"地点"、"方式"等含义，应用when, where, how等词引导。
I have no idea when he will be back.
I have no impression how he went home, perhaps by bike.
4.当主句的谓语较短，而同位语从句较长时，同位语从句常后置。
The thought came to him that maybe the enemy had fled the city.
专项训练：
1. It was true _____ Alice did surprised her mother.
A. that
B. what
C. that, what
D. what, that
2. Does ____ matter much ____he can't come to the meeting.
A. it, if
B. that, if
C. it, whether
D. this, whether
3. --What are you anxious about? -- ____
A. How can we succeed
B. Whether we can succeed
C. When can we succeed
D. That we can succeed
4. The reason ____the little actress has been such a success is ____she is both clever and hard-working.
A. why, why
B. why, that
C. that, because
D. for, because
5. ____leaves the room last ought to turn off the lights.
A. Who
B. Whoever
C. Anyone
D. The person
6. I really don't know _____ I had this photo taken.
A. where it was that
B. it was that
C. where it was
D. it was why
7. Dr. Black comes from either Oxford or Cambridge. I can't remember ____.
A. where
B. there
C. which
D. that
8. --What do you think of China? --____different life is today from ____it used to be.
A. How, what
B. What, what
C. How, that
D. What, that
9. Give this to ____you think can do the work well.
A. who
B. whom
C. whoever
D. whomever
10. ____troubles me is ____I can't learn all these English idioms by heart.
A.That, that
B. What, what
C. That, what
D. What, that
Nick Petrels is a doctor in Montreal. He works 60 hours a week. He takes care of 159 patients a week in the hospital and at his office. He’s been a doctor for ten years.
Dr. Petrels gives his patients good medical advice. But he doesn’t just tell his patients what to do. He also sings to them on television! Dr. Petrels has his own TV show. The show is in Italian, English and French. The doctor starts the show with a song and then gives medical advice. He explains a medical problem or disease in simple language. After that, he sings another song.
Dr. Petrels produces and performs in his own show every week. The program is very popular with his patients and with people who enjoy his singing. His dream is to perform(表演) in Las Vegas. His favorite songs are love songs, and he has a compact disk of lov e songs that he wrote. Dr. Petrels says, “I always loved to sing. All my problems are gone when I sing.” But when Dr. Petrels was young, his father didn’t want him to be a singer, s o he went to medical school.
Some people tell Dr. Petrels he can help people more as a doctor. But Dr. Petrels says he helps people when he sings, too. “I like to make people smile. Sometimes it’s difficult to make a sick person smile. Medicine and entertainment(娱乐) both try to do the same thing. They try to make people feel good.”
1. Dr. Petrels works 60 hours a week, because he _______.
A. gives his patients medical advice
B. takes care of 159 patients a week
C. sings on television
D. has his own TV show
2. Dr. Petrels _______, so he is called a singing doctor.
A. has been a doctor for ten years
B. always loved to sing
C. is popular with his patients
D. also sings to his patients on TV
3. In his TV show, Dr. Petrel _______.
A. sings and gives medical advice
B. sings about different diseases
C. starts to explain diseases with a song
D. sings love songs he wrote
4. Dr. Petrels’ show is popular _______.
A. in Las Vegas.
B. at medical school
C. with people who like his singing
D. with patients in Montreal
5. Dr. Petrels says he likes to _______.
A. help people sing
B. make people feel better
C. do the same thing
D. make difficult people smile
It was a quiet village in which there was a military camp. It was far from the towns and cities and there were some high mountains around. Of course it was a good place for training the new soldiers. But it was difficult for the young men to go outside. Mr. White, an officer of forty, was strict with them and he hardly let them leave the camp.
Once Mr. White was ill in bed. He couldn’t work and a young officer, Mr. Hunt, began to train the new soldiers instead of him. He knew the young men well and let nine soldiers go to the nearest town to have a holiday. But night fell and none came back to the camp. He was worried about it and stood at the gate. It was five to twelve when Mr. Hunt decided to go to the town and see what was happening with the young men. He started the car quickly and set off. At that moment the nine soldiers came back. It seemed they were all drunk. Of course they found the officer was angry.
“I’m sorry, sir,” said the first soldier. “I left the town on time. But something was wrong with my bus on my way here. I had to buy a horse and made it run fast. Bad luck! It d ied and I had to run back.”
And the other seven soldiers said they were late for the same reasons. It was the last soldier’s turn. He said, “I’m sorry, sir. I got on a bus on time, but…”
Having heard this, the officer became even angrier and stopped him at once. He called out, “If you say something was wrong with your bus, I’ll punish you at once!”
“No, no, sir,” said the young man. “My bus was all right, but the dead horses were in its way!”
1. The military camp was built in the village to _______.
A. stop the soldiers going to towns
B. stop the soldiers meeting their friends
C. train the new soldiers
D. make the young men live quietly
2. Mr. Hunt let the nine soldiers have a holiday because _______.
A. he was kind to them
B. they felt lonely
C. they had something important to do
D. they were the best of all
3. The young officer was worried because _______.
A. a traffic accident had happened
B. he was afraid something happened to the nine soldiers
C. the nine soldiers didn’t come back on time
D. the nine soldiers drank too much in the town
4. The nine soldiers returned to the camp late because _______.
A. something was wrong with their buses
B. their horses died on the return way
C. it took them much time to run back
D. they all had drunk much in the town
5. Which answer do you think right?
A. I’ll believe only the last soldier.
B. The officer believed the nine soldiers.
C. I’ll believe none of the nine soldiers.
D. The officer won’t punish his soldiers.
In most towns today, you can see teenagers standing over electronic machines with flashing lights, shooting at spaceships from other planets and dropping bombs on strange monsters(恶魔). The machines have names like Space Warrior, Dark Invader and so on. It used to be believed that damage was done only to those strange visitors from outer space, but now it seems that they are striking back.
Many teenagers like electronic games so much that they can’t stop playing. They spend hours tightly holding the joystick controls and constantly pressing butt ons marked “fire”. They develop pains on their fingers because of the constant pressure. They play and play that the pains have no chance to cure properly. The rapid wrist movement required to guide the spaceship across the screen causes another problem: The muscles of the wrist and arm become so inflamed and swollen(充血红肿) that they press against the b ones. This condition is what doctors now call “Space Warrior’s Wrist”.
Other strange aches and pains also are likely to affect the elbows and shoulders.
Another even more alarming problem is shown by the case of a 17-year-old girl which was recently reported in the British Medical Journal. She had been playing various kinds of electronic games for more than two hours a day. Her father repaired games and machines and she could use the cassettes and systems in his workshop as often as she liked. One day, after playing a game called Dark Invader, she lost consciousness(晕倒) and fell to the floor.
Doctors who examined her found she was suffering from an unusual illness caused by lights flashing at a particular frequency.
1. Electronic games are found very popular with _______.
A. people living in towns
B. students studying in high schools
C. girls working in their father’s workshops
D. young people
2. “Space Warrior’s Wrist” is caused by _______.
A. constantly pressing the buttons
B. rapidly moving across the screen
C. tightly holding the joystick controls
D. inflamed and swollen muscles of the wrist
3. The case of a 17-year-old girl given by the writer shows that the writer _______.
A. supports playing electronic games
B. feels very sorry for the girl
C. disagreed with young people’s playing electronic games
D. feels worried about young people’s poor health
4. From the passage we can conclude that playing electronic games is _______.
A. enjoyable and helpful to the study
B. exciting but harmful to the health and study
C. interesting but harmless to the eyes
D. amusing and satisfying
verilog基本语法
Verilog基本语法 【逻辑值】 逻辑0 表示低电平，GND 逻辑1 表示高电平，VCC 逻辑X 表示未知电平,可能是高电平，也可能是低电平 逻辑Z 表示高阻态，外部没有激励信号，是一个悬空状态 注：高阻态的实质：电路分析时高阻态可做开路理解。 可以把它看作输出（输入）电阻非常大，对下级电路无任何影响。 若为0、x、z则按照假处理；若为1，按真处理。 【进制】 二进制4'b0101 —4位二进制数0101 十进制数4’d2 —4位十进制数2 十六进制数4’ha —4位十六进制数a Verilog中若不指定位宽，默认32位；若不指定位宽不指定进制，默认32位宽的十进制数。 【标识符】 标识符可以是字母、数字、$和_（下划线）的组合，且开头必须是字母或下划线，区分大小写。不建议大小写混合使用。 【数据类型】 寄存器关键字reg，默认初始值位不定值X； reg[31:0] delay_cnt; //[31:0],指定寄存器位宽32位， reg key_reg; // 默认位宽为1. reg类型数据只能在always和initial语句中被赋值。 线网表示结构实体的物理连线，包括wire和tri类型 参数常量，用parameter定义。 parameter H_SYNC = 11'd41; 【运算符】 [条件操作符] ?: 例，a?b:c //如果a为真就选b，否则选择c。 result=(a>=b)?a:b; [逻辑运算符] ！&& || [位运算符] ~ & | ^（按位异或） a&b; //自动将位宽小的数高位补零至较大数的位宽，然后按位与操作。[移位运算符] << >> 用0填补移出的空位。左移时位宽增加，右移位宽不变。 [位拼接运算符] {} 例，{a,b} //将a和b拼接起来，作为一个新信号,a为高位。 c={a,b[3:0]}; //a、b位宽均为8位，c为8+4=12位。
01-Cobol-基础知识讲义
第一章关于COBOL的初步知识 一. COBOL语言的特点 COBOL是Common Business-Oriented Language（公用面向商业的语言）的缩写，主要供数据处理、数据收集及分析之用。COBOL自60年代初开始广泛应用于计算机应用领域（商业和其他领域）。事实上，除了商业之外，各种管理工作都广泛使用COBOL,如各种统计工作，财会工作，企业计划编制，作业制度，情报检索，人事管理等。COBOL针对商业世界的使用，是真正商用应用程序开发的首选语言。 ． 1 适于数据处理领域。 ． 2 采用英语语法的高级语言，可读性、可维护性、可移植性较强。 3 ． 通用性强，标准化程度较高。 ． 4 结构严谨，层次分明。 ． 5 缺点是比较繁琐。 ． 最简单的COBOL程序介绍 二例１： IDENTIFICATION DIVISION.(标识部) PROGRAM-ID. EXAM1.（程序标识段） ENVIRONMENT DIVISION.（设备部） DATA DIVISION.（数据部） PROCEDURE DIVISION.（过程部） A. DISPLAY ‘THIS IS A COBOL PROGRAM.’. STOP RUN. 例２： IDENTIFICATION DIVISION.(标识部) PROGRAM-ID. EXAM２.（程序标识段） ENVIRONMENT DIVISION.（设备部） DATA DIVISION.（数据部） WORKING-STORAGE SECTION.(工作单元节) 77 A PICTURE IS 9(3).（对Ａ进行描述） 77 B PICTURE IS 9(3).（对Ｂ进行描述） PROCEDURE DIVISION.（过程部） S. ACCEPT A.（输入Ａ值） ACCEPT B.（输入Ｂ值） ADD A TO B.(A+B->B) DISPLAY A,B.（显示Ａ和Ｂ值） STOP RUN. 三．COBOL程序的结构 1．部 每个程序都包括四个部： IDENTIFICATION DIVISION （标识部）提供程序的一般性文档说明，主要用来指定源程序名。 ENVIRONMENT DIVISION （环境部）列出程序中所用到的文件。程序中不需要外部文件时，环境部为空，也可以省略部标题。 DATA DIVISION （数据部）程序中所用到的全部数据（包括：文件数据—-用于输入输出、静态数据、参数等）都应在数据部中说明它们的类型和所占内存的情况。 PROCEDURE DIVISION （过程部）包含构成程序的过程性语句，用来给出程序要执行的指令，使计算机产生相应的操作。 2．节和段 标识部下只有各个段。除标识部以外，每个部下可以有若干个节（SECTION），每个节以“节头”作标识。每个节下又可包括若干段（PARAGRAPH），每个段用“段名”标识。各个段内有各种COBOL元素。 3．句子，语句和子句 在过程部中，每一段由若干个句子（Sentence）组成。一个句子是以英文句号来结束的。句子又由语
cobol基本语法教学内容
c o b o l基本语法
基本語法 一、COBOL基本語法 一、cobol的书写格式（每行） 1、前6列为序号区(一般不编辑) 2、第7列为标示列，仅可以写如下几个标示符。 a. “＊”注释符(注释当前行的代码) b “－“字符串连接符 3、第8列---11列为A区，包括以下内容。 a 部、节名。 b 层号01 4、第12列---72列为B区，过程部的程序必须写在B区中。 5、第72以后部分不能编辑。 二、cobol的语法结构 (几大部分) 1、标示部(IDENTIFICATION DIVISION):提供程序的一般性文档说明。 2、环境部(ENVIRONMENT DIVISION): 提供程序外部有关的项目。 a.配置节(CONFIGURATION SECTION) ①.指定源计算机(SOURCE-COMPUTE). ②.目标计算机(OBJECT-COMPUTE). b. 输入输出节(INPUT-OUTPUT SECTION). 文件的物理路径的定义。 方法二:(过程部中动态指定文件) SELECT FILE-LOG ASSIGN TO SELECT-FILE ORGANIZATION IS LINE SEQUENTIAL. 在数据部定义字符串变量SELECT-FILE,在文件FILE-LOG打开前动态指定文件路径。 3、数据部(DATA DIVISION)。 程序中的变量都在数据部中定义，Cobol中没有全局变量和局部之分。（变量的类型结构参照5.变量类型） a. 文件节(FILE SECTION) 给环境部定义的文件指定一个RECORD变量，读写文件用: FD FILE-LOG. 01 RECORD-LOG PIC X(2000). b. 工作存储节 定义程序中用到的临时变量。 a) COBOL变量定义需要加层号(表示层次关系), ·层号从01开始 如: 01 I PIC X(10). ·组合项 如: 01 WORK-AREA. 05 NUM-1 PIC 9(09).
从Verilog到VHDL(上)基本语法
从Verilog 到VHDL（上）基本语法 16 六 从学校里开始,我所接触的就一直是VerilogHDL 而非更老牌的VHDL, 而且后续接触的项目中也多半是Verilog 的用户，坦白的讲，Verilog 的活力也确实更足一些，从 IEEE1800-2005 开始的SystemVerilog 的标准化，将 Verification 和Design 的一体化的尝试，我个人认为，是走在正确的道路上。 所以，我确实想不到，我竟然也要回头学起VHDL 来了，毕竟一些老牌公司，特别是欧洲的公司，往往因为历史原因，仍然在使用VHDL ，看来终究是绕不过去的了正如一个Design Verification 工程师在目前想完全的不和SpecmanE 打交道是很难的一样。 面记载的是两种语言学习过程中的一些体会，而且更多的是从语法角度出发，算是梳理一下思路吧，而且，以前从来 没有接触过VHDL ，当然会存在很多非常初级的东西。 而在本文之后，打算再写一篇简单阐述下结合Cadence 的IUS 工具，使用SystemVerilog 对VHDL 进行验证的基本方
法。 起手式从Verilog 撞进VHDL 的世界，有些东西要先搞清 楚，否则会一头雾水： 1. 大小写敏感：Verilog 是大小写敏感的，VHDL 则非； 2.注释：Verilog 的行注释为// ，块注释为/**/;VHDL 只 支持 行注释–;[1. 这个算是不方便的一个地方了，不过不 基本结构 论是在Vim 还是Emacs 当中，批量做行注释也很容易实现；] VHDL 被认为是要求更严格，更多讲究的语言，相比和 C 类 似的Verilog ，架构上更严谨一些： 1.基本结构：从上往下为 USE 定义区（调用库和包）；Package 定义区（自定义程序包）；Entity定义区（定义电路实体外观，I/O接口的规 格）; [2. Entity 感觉像是 C 的头文件定义之类的东西，而在Verilog 当中，这些其实都是被整合在Module 里头一起完成 了。]Architecture 定义区（描述内部功能）；[3. 同 上，相当于Verilog 的Module 内部实现。]Configuration 定义区（决定那个Architecture 被使用）[4. 这也许就是 之所以要分开 Arch 和Entity 的原因，类似的效果在Verilog 里实现，则
COBOL面试1—30题答案
COBOL面试1—30题答案 A1) IDENTIFICA TION DIVISION, ENVIRONMENT DIVISION, DA TA DIVISION, PROCEDURE DIVISION. Q：列举COBOL的DEVISION A：标识部，环境部，数据部，过程部 A2) Alpha-numeric (X), alphabetic (A) and numeric (9). Q：COBOL有哪些可用的数据类型 A：字符型（这里指的是包含字母和数字），字母型，数字型 A3) Alphabetic, Alphanumeric fields & alphanumeric edited items are set to SPACES. Numeric, Numeric edited items set to ZERO. FILLER , OCCURS DEPENDING ON items left untouched. Q：INITIALIZE这个词做了些什么 A：将字母，字符，数字区域都置成空格（置空），将数字区置0，FILLER和OCCURS DEPENDING ON项不处理 A4) Elementary level item. Cannot be subdivisions of other items (cannot be qualified), nor can they be subdivided themselves. Q：77层有什么作用 A：基本层数据项，不能用做细分别的层，也不能被细分 A5) For condition names. Q：88层有什么作用 A：条件逻辑层 A6) For RENAMES clause. Q：66层有什么作用 A：重命名层 A7) IS NUMERIC can be used on alphanumeric items, signed numeric & packed decimal items and unsigned numeric & packed decimal items. IS NUMERIC returns TRUE if the item only consists of 0-9. However, if the item being tested is a signed item, then it may contain 0-9, + and - . Q：IS NUMERIC这个子句怎么确定（也就是说确定句子的真值） A：IS NUMERIC用在字符项，带符号数字，浮点数，不带符号数。如果目标项只含0~9则返回TRUE。但是，如果待测项目是个带符号数，那么他就含有0-9还有+和- A8) ARRAYS. 05 ARRAY1 PIC X(9) OCCURS 10 TIMES. 05 ARRAY2 PIC X(6) OCCURS 20 TIMES INDEXED BY WS-INDEX Q：COBOL中怎么建表/数组 A：如上.
浅谈COBOL开发
浅谈COBOL开发 近几年，由于IBM和HITACHI等大型机力推COBOL，使COBOL在沉睡了几年以后又重新火了起来。因为本人从毕业以来，一直在做COBOL的项目，今天斗胆把毕业以来的一些经验写出来，不管对还是错拿出来大家一起讨论讨论。 COBOL语言常用的开发方式有以下几种： 1． PC机开发。这种开发方式比较灵活，可以与当今比较流行的语言进行对接。把数据库、及开发环境都可以集成到我们的PC机上。程序执行的LOG和文件都在PC机上指定目录。当今比较流行的语言如.net、 VB、 C++等编译生成的LIB文件，COBOL都可以直接调用。这种开发方式所使用的开发工具中首推日立推出的COBOL2002，还有一个比较低的版本COBOL85，COBOL2002的优势在于DB连接方面。当然由于COBOL85版本太老，本人无缘使用，但是曾经听过一位前辈说COBOL85不能进行DB连接，也就是说COBOL85的数据存储只能以文件的形式存储。COBOL2002可以设定断点（VB、.NET程序员应该比较熟悉），程序执行过程中可以单步调试，察看变量值。COBOL2002还可以记录测试路径的覆盖率，一些异常处理可以利用设定断点的方式跑到，所以这种开发方式可以出现路径覆盖率为100%的情况。但是这种开发形式的语法要求比较低，比如说代码中出现全角空格就能顺利通过编译，而相同的代码在大机上编译就会出错。 2．B/S形式大机开发。程序员在PC机上开发，代码编写完成以后，通过FTP上传工具，把代码上传到大机端。利用远程登录telnet登录大机，在命令行输入编译代码。本身程序员在编写代码过程中完全占用PC机资源，不占用大机内存资源。当程序被传到大机上以后，才占用大机资源。由于大机是多用户多线程作业，所以即使代码死循环，大机也不会停掉。而是在这个线程执行一段时间以后，压到堆栈中，执行其他线程。这种大机典型的是H9000（HITACHI9000，个别人可能误以为是HP的产品）。大机上常常把目录固定，主处理和子程序往往在不同的目录下存放。程序执行过程中无法设定断点。如果想要查看程序执行过程中的变量，只能在代码中追加DISPLAY语句，在LOG中把变量值打出来。一般来说，大机的语法要求高一些，代码里除了X型变量中和注释出现全角空格外，其他地方出现空格是绝对不能编译通过的。 3．HOST端大机开发。程序员通过个人计算机和网络和大机相连，在编写代码的过程中，占用大机资源。就是说如果你PC删除一行代码，对应大机上也要删除一行代码。编写的代码无法在PC机上进行编译，代码需要使用大机的操作系统命令进行编译和执行。代码编写操作远远没有ULTRAEDIT方便，删除、拷贝都需要系统命令。而且要进行用户登录和退出。开发担当常常用一个文本记下所有常用命令，以便开发过程使用。这种开发的典型就是IBM 的S/390
Cobol基础
Cobol 语法基础 作成者审查者承认者 丁成远 变更履历 日期版本作成者备注 2005-03-01 1.0 丁成远初版
一．COBOL 语言的特点 最适于数据处理领域：算数计算量少而逻辑处理量多，输入输出量大，数据间存在着一定的逻辑关系，大量的分类排序；COBOL 比较接近英语，容易懂；通用性强，易植,COBOL结构严谨，层次分明。 二. COBOL的组成部分 1．标识部（IDENTIFICATION DIVISION）：用于标识程序名。
IDENTIFICATION DIVISION. PROGRAM-ID. 程序名。 [AUTHOR。作者名。 ] [INSTALLATION。计算机设置场所。 ] [DATE-WRITTEN。源程序编写日期。 ] [DATE-COMPILED。源程序编译日期。 ] [SECURITY。保密程度。] 2．环境部（ENVIRONMENT DIVISION）：用于说明程序运行的环境。ENVIRONMENT DIVISION. CONFIGRATION SECTION。 SOURCE-COMPUTER。源计算机名。 OBJECT-COMPUTER。目标计算机名。 [SPECIAL-NAMES。专用名描述项。 ] [INPUT-OUTPUT SECTION。 FILE-CONTROL。 {文件控制描述体} [I-O-CONTROL。输入输出控制描述体]] 3．数据部（DATA DIVISION）：用于说明程序中涉及的所有数据。4．过程部（PROCEDURE DIVISION）：是程序的核心部分，它决定计算机应进行什么操作。
cobol基本语法
基本語法 一、COBOL基本語法 一、cobol的书写格式（每行） 1、前6列为序号区(一般不编辑) 2、第7列为标示列，仅可以写如下几个标示符。 a. “＊”注释符(注释当前行的代码) b “－“字符串连接符 3、第8列---11列为A区，包括以下内容。 a 部、节名。 b 层号01 4、第12列---72列为B区，过程部的程序必须写在B区中。 5、第72以后部分不能编辑。 二、cobol的语法结构 (几大部分) 1、标示部(IDENTIFICATION DIVISION):提供程序的一般性文档说明。 2、环境部(ENVIRONMENT DIVISION): 提供程序外部有关的项目。 a.配置节(CONFIGURATION SECTION) ①.指定源计算机(SOURCE-COMPUTE). ②.目标计算机(OBJECT-COMPUTE). b. 输入输出节(INPUT-OUTPUT SECTION). 文件的物理路径的定义。 方法二:(过程部中动态指定文件) SELECT FILE-LOG ASSIGN TO SELECT-FILE ORGANIZATION IS LINE SEQUENTIAL. 在数据部定义字符串变量SELECT-FILE,在文件FILE-LOG打开前动态指定文件路径。 3、数据部(DATA DIVISION)。 程序中的变量都在数据部中定义，Cobol中没有全局变量和局部之分。（变量的类型结构参照5.变量类型） a. 文件节(FILE SECTION) 给环境部定义的文件指定一个RECORD变量，读写文件用: FD FILE-LOG. 01 RECORD-LOG PIC X(2000). b. 工作存储节 定义程序中用到的临时变量。 a) COBOL变量定义需要加层号(表示层次关系), ·层号从01开始 如: 01 I PIC X(10). ·组合项 如: 01 WORK-AREA.
COBOL语言测试试卷(一)
COBOL语言测试试卷（一） 一、选择题（共10分） 1、关于COBOL语言，下述描述中正确的是：（） A.COBOL可以用于开发操作系统。 B.COBOL还可以用于开发编译器。 C.COBOL主要用于编写面向商业的应用程序。 D.如今比较少用COBOL开发应用程序。 2、不属于COBOL程序的部的是：（） A.过程部。 B.程序部。 C.数据部 D.环境部 3、COBOL代码中最小的单位是：（） A. Division B. Section C. Sentence D. Statement 4、COBOL程序中的数据在哪个部中定义？（） A.过程部。 B.环境部。 C.数据部 D.定义部 5、COBOL程序中如果有环境部的话，应置于：（） A.过程部之后定义部之前。 B.定义部之后过程部之前。 C.定义部之后数据部之前。 D.数据部之后过程部之前。 6、定义部中不可缺少的段名是：（） A.PROGRAM-ID B.AUTHOR C.FILE SECTION D.PROGRAM 7、COBOL程序中一般变量在哪里定义？（） A.定义部 B.环境部 C.数据部的FILE SECTION D.数据部的WORKING-STORAGE SECTION 8、在过程部中，可以没有的是：（） A.SECTION B.PARAGRAPH C.SENTENCE D.STATEMENT 9、当一个COBOL编译器区分A区和B区的时候，必须从B区开始的是：（） A.段名 B.节名和01级数据 C.部名 D.过程部里的Sentences。 10、在COBOL程序中，下列用户自定义的名称有效的是：（） A.This result B.-Grosspay C.Grosspay- D.Gross-pay 二、判断题（共20分）
Verilog语法入门,初学者必看
Verilog的词法约定 1Verilog是大小写相关的，其中的关键字全部为小写。 2空白符由空格、制表符、和换行符组成。 3单行注释以“//”开始，verilog将忽略此处到行尾的内容。多行注释以“/*” 开始，以“*/”结束。多行注释不允许嵌套 4操作符有三种：单目操作符、双目操作符和三目操作符。 5数字声明 Verilog中有两种数字生命：指明位数的数字和不指明位数的数字 指明位数的数字表示形式：
VerilogHDL语法基础
Verilog HDL语法基础(1) Verilog的词法约定 1Verilog是大小写相关的，其中的关键字全部为小写。 2空白符由空格、制表符、和换行符组成。 3单行注释以“//”开始，verilog将忽略此处到行尾的内容。多行注释以“/ *”开始，以“*/”结束。多行注释不允许嵌套 4操作符有三种：单目操作符、双目操作符和三目操作符。 5数字声明 Verilog中有两种数字生命：指明位数的数字和不指明位数的数字 指明位数的数字表示形式：
COBOL经典面试题库(中文)
COBOL经典面试题库 Q1：列举COBOL的DEVISION A1：标识部，环境部，数据部，过程部 Q2：COBOL有哪些可用的数据类型 A2：字符型（这里指的是包含字母和数字），字母型，数字型 Q3：INITIALIZE这个词做了些什么 A3：将字母，字符，数字区域都置成空格（置空），将数字区置0，FILLER和OCCURS DEPENDING ON项不处理 Q4：77层有什么作用 A4：基本层数据项，不能用做细分别的层，也不能被细分 （来源：） Q5：88层有什么作用 A5：条件逻辑层 Q6：66层有什么作用 A6：重命名层 Q7：IS NUMERIC这个子句怎么确定（也就是说确定句子的真值） A7：IS NUMERIC用在字符项，带符号数字，浮点数，不带符号数。如果目标项只含0~9则返回TRUE。但是，如果待测项目是个带符号数，那么他就含有0-9还有+和- 05 ARRAY1 PIC X(9) OCCURS 10 TIMES. 05 ARRAY2 PIC X(6) OCCURS 20 TIMES INDEXED BY WS-INDEX Q8：COBOL中怎么建表/数组 A8：如上. Q9：OCCURS 子句能用在第一层吗 A9：不能 Q10：索引和下标有什么区别 A10：下标可以指定数组中任意中位置的元素（只要知道其下标），下标只能是数字型常量或者数字型变量（但是不能在指定的时候修改，如：A（K+1）这样是不行的，要修改的话要在指定的外部改，如：ADD 1 TO K，而索引的话是从表头/数组头开始检索（以BY N的指定检索规律往后滚） 再者，索引只能通过PERFORM, SEARCH 和SET来修改，如果要在一个表中使用SEARCH, SEARCH ALL，那这个表就要有索引（因为SEARCH, SEARCH ALL的参数中指定索引，所以即使其有很多限制还是得用它）
COBOL语法和文法
COBOL语法和文法 REDEFINES 可以用不同的变量描述同一内存。 01 PART_RECODE USAGE DISPLAY 03 PART-TYPE PICTURE... 03 PART_TYPE_A. 05 PART_NUMBER PICTURE... 05 PART_COST PICTURE... 03 PART_TYPE_B REDEFINES PART_TYPE_A. 05 UPC_CODE PICTURE... 03 PART_TYPE_C REDEFINES PART_TYPE_A. 05 ISBN PICTURE... 根据PART_TYPE决定用PART_TYPE_A还是PART_TYPE_B还是PART_TYPE_C。 规则： PART_TYPE_B和PART_TYPE_C长度不能大于PART_TYPE_A。 数据项不能有VALUE。 01层不能用REDEFINES. PART_TYPE_B和PART_TYPE_C中不能有OCCURS. PICTURE 定义基本项目的具体长度，格式，数据类型。可以简写成PIC. 格式字符串最多30个字符，可以包含下列字符： A 字母A-Z,a-z,空格 B 插入空格 P 标量字符，代表字段中不显示的小数点位置 S 代数符号，实际显示取决于项目的USAGE V 小数点位置 X 任何字符 Z 抑制前头的0并转换成空字符 0 插入0 9 数字0~9 / 插入/ , 插入,(逗号不能作为字符串的最后一位，最后时逗号是分隔符) 。插入。 * 抑制前头的0并转换成* + 正值插入+，负值插入- - 正值插入空格，负值插入- $ 插入美元号 CR 正值插入两个空格，负值插入CR DB 正值插入两个空格，负值插入DB 例子： 03 VAR PIC AAAAA. STATE变量长度为5个字符，不能有数字，等价于03 STATE PIC A(5)。
COBOL试题答案
一、选择题(15分)（含多项选择） 1、不属于COBOL程序的部的是：（B ） A.过程部。 B.程序部。 C.数据部 D.环境部 2、COBOL程序中的数据在哪个部中定义？（C ） A.过程部。 B.环境部。 C.数据部 D.标识部 3、COBOL程序中如果有环境部的话，应置于：（C ） A.过程部之后标识部之前。 B.标识部之后过程部之前。 C.标识部之后数据部之前。 D.数据部之后过程部之前。 4、标识部中不可缺少的段名是：（A ） A.PROGRAM-ID B.AUTHOR C.FILE SECTION D.PROGRAM 5、COBOL程序中一般变量在哪里定义？（D ） A.标识部 B.环境部 C.数据部的FILE SECTION D.数据部的WORKING-STORAGE SECTION 6、下列关于过程部的说法正确的是：（C ） A.过程部中可以不定义节但是必须定义段 B.过程部中可以不定义段但是必须定义节 C.过程部中可以不定义节和段，节和段是根据需要定义的 D.所有程序都是在过程部中以STOP RUN来结束的 7、下面是COBOL合法数据名的是：（ABD ） A.W ANG B.TAN-1 C.12345 D.END-OF E.PROGRAM F.GROSS-$ G.SECTION 8、关系运算符的优先顺序正确的是（A ） A.NOT > AND > OR B.OR> NOT > AND C.AND > NOT > OR D.NOT > OR > AND 9、下记语句表示A/B=>C的是（B ） A.DIV A INTO B GIVING C. B.DIV A BY B GIVING C 10、下记哪些方法可以显示出…ABCD?六个字符（A,C ） A. PIC X(6) VALUE "'ABCD'". 说明：V ALUE后依次为空格双引号单引号ABCD单引号双引号 B. PIC X(6) V ALUE ''ABCD''.说明：V ALUE后依次为空格单引号单引号ABCD单引号单引号 C. QUOTE ?ABCD? QUOTE 11、COBOL对文件的操作以为单位的（B ） A.整个文件 B.记录 C.字段
Cobol基本语法总结
コボル基本語法 一、COBOL基本語法 compla項目使用的Cobol是Micro Focus 公司生产的Cobol,采用在HP-UNIX上运行。 一、cobol的书写格式（每行） 1、前6列为序号区(一般不编辑) 2、第7列为标示列，仅可以写如下几个标示符。 a. “＊”注释符(注释当前行的代码) b “/“注释符(注释当前行的代码,程序编译时，强制程序清单另起一页,不建议使用) c “－“字符串连接符 d “D”DEBUG行标示符(程序为DEBUG模式时，标有该标示符的语句行代码执行，否则和注 释行效果一样) 3、第8列---11列为A区，包括以下内容。 a 部、节名。 b 层号01 4、第12列---72列为B区，过程部的程序必须写在B区中。 5、第72以后部分不能编辑。 二、cobol的语法结构(几大部分) 1、标示部(IDENTIFICATION DIVISION):提供程序的一般性文档说明,本项目只保留程序名 (PROGRAM-ID)一项。 2、环境部(ENVIRONMENT DIVISION): 提供程序外部有关的项目。 a.配置节(CONFIGURATION SECTION) ①.指定源计算机(SOURCE-COMPUTE). ②.目标计算机(OBJECT-COMPUTE). ③.设置debug模式(SOURCE-COMPUTE H9000V WITH DEBUGGING MODE) ④. 指定读环境变量设置. SPECIAL-NAMES. ENVIRONMENT-VALUE IS CNS-ENV-PARM ENVIRONMENT-NAME IS CNS-ENV-NAME. b. 输入输出节(INPUT-OUTPUT SECTION). 文件的物理路径的定义。 方法一：(写死文件路径) SELECT FILE-LOG ASSIGN "/usr3/WSI/commonlog/WSI1101.log" ORGANIZATION IS LINE SEQUENTIAL. 方法二:(过程部中动态指定文件) SELECT FILE-LOG ASSIGN TO SELECT-FILE ORGANIZATION IS LINE SEQUENTIAL. 在数据部定义字符串变量SELECT-FILE,在文件FILE-LOG打开前动态指定文件路径。 方法三:(环境变量中动态指定文件)
第二章Verilog基本知识
2.1 Verilog HDL的语言要素 Verilog HDL语法来源于C语言基本的语法，其基本此法约定与 C语言类似。 程序的语言要素称为语法，是由符号、数据类型、运算符和表达式构成的，其中符号包括空白符、注释符、和转义标示符、关键字、数值等。 2.1.1 空白符 空白符包括空格符(\b),制表符(\t)、换行符和换页符。空白符使代码看起来结构清晰，阅读起来更方便。在编译过程中，空白符被忽略。 2.1.2 注释符 Verilog HDL语言允许插入注释，标明程序代码功能、修改、版本等信息，以增强程序的可阅读性和帮助管理文档。 Verilog HDL有两种注释方式 1) 单行注释：单行注释以“ // ”开始，Verilog HDL 忽略从此处到行尾的内 容 2) 多行注释：多行注释以“ /* ”开始，到“ */ ”结束，Verilog 忽略 其中的注释内容
在Verilog HDL 中，标识符( Identifier )被用来命令信号名、模块名、参数名等。它可以使任意一组字母、数字、$符号和_符号的组合。应该注意的是，标识符的字符区分大小写，并且第一个字符必须是字母或者下划线 Verilog HDL规定了转义标识符(Escaped Identifie) 采用转义字符可以在一 条标识符中包含任何可打印的字符。转义标识符以“ ”(反斜线)符号开头，以 空白符结尾(空白可以是一个空格、一个制表符或者换行符) 2．1.4 关键字 Verilog HDL语言内部已经使用的词称为关键字或保留字，它是 Verilog HDL语言的内部专用词，是事先定义好的确认符，用来组织语言结构的。需要注意的是，在Verilog HDL中,保留字都是小写的。
cobol 知识点集锦
cobol 知识点集锦 COBOL数据类型 计息是银行的一项重要业务，包括日常代理客户收、付计算客户利息和年度计息等。目前，这些工作大多数是在IBM ES9000主机的SAFE应用系统平台上进行，该系统联 机程序和联机计息程序是用IBM 370汇编语言实现的。为方便汇编语言读写，在VSAM文 件存储的数据中，数据存放格式进行了特殊的定义。如日期存放采用X(3)型，01年03月15日，存入EBCD码为X‘010315’。在进行年度计息时，为了实现各种复杂的运算工作，一般采用COBOL语言来实现各种运算。而采用COBOL语言读取X(3)型数据时，读出的是字符型数据，不能直接进行运算，必须转换为COBOL数据类型的数据后才能进行相应处理。 如刚才的X‘010315’，需要转换为内部十进制数据X‘0010315C’。本文介绍一种用COBOL语言实现字符型X(3)与内部十进制数据相互转换的方法。 由X(3)型转换为内部十进制 由于日期数据总是大于零，在COBOL语言的工作单元节定义变量DATE－FIRST后，再追加 定义COBOL语言的最小数据单元X‘000C’，即十进制12。由于重定义DATE－CASE为DATE－CHANGE后，DATE－CHANGE是原日期数据的1000倍，于是要在过程部将DATE－CHANGE除以1000。 首先，在COBOL程序WORKING－STORAGE SECTION. 中定义如下内容： WORKING－STORAGE SECTION. 01 DATE－CASE. 02 DATE－FIRST PIC X(3). 02 DATE－SIGN PIC 9(4) COMP VALUE 12.；定点二进制数 01 DATE－CHANGE REDEFINES DATE－CASE PIC 9(9) COMP－3. ；内部十进制数据 01 DATE－HEX PIC X（3）. ；转换前数据 01 DATE－DEC PIC S9（7）COMP－3 . ；转换后数据 然后，在过程部PROCEDURE DEVISION.中加入如下语句： PROCEDURE DEVISION. MOVE DATE－HEX TO DATE－FIRST . COMPUTE DATE－CHANGE = DATE－ CHANGE / 1000.
COBOL谭浩强版学习笔记
COBOL资料整理 COBOL语言概述 一．COBOL程序的结构 1．部 IDENTIFICATION DIVISION 标识部 ENVIRONMENT DIVISION 环境部 DA TA DIVISION 数据部 PROCEDURE DIVISION 过程部 2．节（SECTION）和段（PARAGRAPH） （1）部-节-段 （2）标识部下面不设节，直接设段 （3）过程部可以设节，下面再设段，也可以直接设段 3．句子、语句和子句 每一段由若干句子（Sentence）组成，一个句子以句号加上一个以上的空格来结束。 句子由语句（Statement）组成。 语句中又可以包含若干子句（clause），每一个子句也有一个动词（但这个动词往往是可以省略的），它指定某一方面的特定功能。 二．COBOL源程序的书写格式 1．1-6列：标号区 2．第7列：续行标志区（“-”为续行，“*”为注解） 3．8-11列：A区（部头，节头，段头，层号01、77，文件描述符FD等） 4．12-72列：B区（正文） 5．73-80列：注释区 三．COBOL字符 数字0-9，大写字母A-Z，小写字母a-z， 专用字符15个{ + - * / = , . ; ‘( ) < > $ 空格} 四．常量 1．数值常量 （1）小数点不能多于一个，而且不能出现在常数最右边。 （2）数值常量的长度不能超过18位数字。 （3）至少要有一个数字，不能有多于一个符号。 （4）数字间不能有空格，空格是分界符。 2．非数值常量 （1）用’’把字符串包起来 （2）假如要把’’放到非数值常量中，用QUOTE保留字， 如MOVE QUOTE ‘CHINA’QUOTE TO A （3）长度不应超过120个字符。
cobol学习笔记
cobol学习笔记(1) COBOL入門 COBOLとは？ 2010/06/29 16:35 COBOL面向商业的通用语言 (Common business Oriented Language) コボル ? 1960.04 CODASYL-60 ? 1968. ANSI COBOL(COBOL68)第1次規格 ? COBOL74 第2次規格 ? COBOL85 第3次規格 ? COBOL2002 第4次規格 COBOL是Common Business-Oriented Language（公用面向商业的语言）的缩写，主要供数据处理、数据收集及分析之用。COBOL自60年代初开始广泛应用于计算机应用领域（商业和其他领域）。事实上，除了商业之外，各种管理工作都广泛使用COBOL,如各种统计工作，财会工作，企业计划编制，作业制度，情报检索，人事管理等。COBOL针对商业世界的使用，是真正商用应用程序开发的首选语言。 1．适于数据处理领域。 2．采用英语语法的高级语言，可读性、可维护性、可移植性较强。 3．通用性强，标准化程度较高。 4．结构严谨，层次分明。 5．缺点是比较繁琐。 cobol的书写格式（每行） 1、前6列为序号区(一般不编辑) 2、第7列为标示列，仅可以写如下几个标示符。 a. “＊” 注释符(注释当前行的代码) b “/“ 注释符(注释当前行的代码,程序编译时，强制程序清单另起一页,不建议使用) c “－“ 字符串连接符 d “D” DEBUG行标示符(程序为DEBUG模式时，标有该标示符的语句行代码执行，否则和注释行效果一样) 3、第8列---11列为A区，包括以下内容。 a 部、节名。 b 层号01 4、第12列---72列为B区，过程部的程序必须写在B区中。 5、第72以后部分不能编辑。 cobol学习笔记(2)COBOL的程序结构 IDENTIFICATION DIVISION 标识部見出し部 2010/06/29 20:44 COBOL程序由4部(DIVISION)组成：IDENTIFICATION DIVISION.(标识部)、ENVIRONMENT DIVISION.(环境部)、DATA DIVISION.(数据部)、PROCEDURE DIVISION.(过程部)，而每个部又由若干节 (SECTION)组成。
cobol介绍
英文缩写: COBOL (Common business Oriented Language) 中文译名: COBOL语言 解释: 一种适合于商业及数据处理的类似英语的程序设计语言。这种语言可使商业数据处理过程精确表达。 COBOL（面向商业的通用语言，又称为企业管理语言、数据处理语言等，Common Business Oriented Langauge）是最早的高级编程语言之一，是世界上第一个商用语言。 1 COBOL的历史 1959年5月，五角大楼委托格雷斯·霍波（G.Hopper）博士领导一个委员会并由Rear Admiral Grace Hopper公司主持开发，并于1961年由美国数据系统语言协会公布。正式发布于1960年4月，称为Cobol－60。1959年12月出现了第一个COBOL语言文本，并于1960年4月正式发表，因此也被称为COBOL-60。1968年美国国家标准委员会ANSI 又通过了新的标准ANSI COBOL X.3.23-1968。1972年国际标准化组织ISO将其作为ISO COBOL-72。1974年ANSI对COBOL-68作出了修订扩充，形成了ANSI COBOL X3.23-1974，随后1978年ISO采用其形成ISO COBOL-78，后来又提出了ANSI X3.23-85，增加了很多结构化程序设计的内容，ISO标准ISO1989:1985也采用了该标准。COBOL 标准还在不断地改进和完善，最新的标准COBOL 2002主体已经于2002年12月出版，其他部分还在不断地完善之中。现在最新的版本是Cobol－2002。 1963年，美国国家标准研究所(ANSI)进行了标准化，但是ANSI标准很少被遵循；因此，COBOL程序只是部分可移植的。 2 COBOL的重要性 经过40多年的不断修改、丰富完善和标准化，COBOL已发展为多种版本的庞大语言，在财会工作、统计报表、计划编制、情报检索、人事管理等数据管理及商业数据处理领域，都有着广泛的应用。 COBOL的重要性可以用这句话来描述：世界上70％的数据都是用COBOL语言处理的，并且90％的A TM事务处理用的都是COBOL语言。每天在线处理的COBOL事务有300亿次。500强中有492家（包括全部的100强）使用了COBOL语言，目前在COBOL方面的投资已经超过3万亿美元，，据称用COBOL书写的程序超过了1000亿行，并且以每年大约50亿行代码的速度在增长。 由于COBOL在商业领域的雄厚基础，而且COBOL主要是应用于银行、金融和会计行业等非常重要的商业数据处理领域。所以，即使对于具有相当经验的IT公司来说，重新编写COBOL语言的可靠的应用软件也是不实际或是从商业角度上并不可行的，而且还要花上很长的时间，只要大型机存在，COBOL就不会消失，即使是对电脑界产生巨大影响的“千年虫”（Y2K）也没有改变COBOL的命运。 3 COBOL的特点 COBOL是一种面向数据处理的、面向文件的、面向过程(POL)的高级编程语言，是一种功能很强而又极为冗长的语言。 COBOL适合于具有循环处理周期的环境(例如打印工资支票)以及数据操纵量相当大的环境。COBOL主要应用于商业数据处理领域，对各种类型的数据进行收集、存储、传送、分类、排序、计算及打印报表、输出图象是它的强项。 COBOL语法与英文很接近，即使不懂电脑的人也能看懂程序。 强大的文件处理功能，大量的数据通常以文件的形式存储在磁盘上。 仅提供了加、减、乘、除及乘方这五种简单的算术运算，因而不适于进行科学计算。 未来的COBOL将支持XML等Web时代的新技术。 4 COBOL的程序结构