三種方法讀取鍵值 使用者設(shè)計(jì)行列鍵盤(pán)介面，一般常採(cǎi)用三種方法讀取鍵值。 中斷式 在鍵盤(pán)按下時(shí)產(chǎn)生一個(gè)外部中斷通知CPU，並由中斷處理程式通過(guò)不同位址讀資料線上的狀態(tài)判斷哪個(gè)按鍵被按下。 本實(shí)驗(yàn)採(cǎi)用中斷式實(shí)現(xiàn)使用者鍵盤(pán)介面。 掃描法 對(duì)鍵盤(pán)上的某一行送低電位，其他為高電位，然後讀取列值，若列值中有一位是低，表明該行與低電位對(duì)應(yīng)列的鍵被按下。否則掃描下一行。 反轉(zhuǎn)法 先將所有行掃描線輸出低電位，讀列值，若列值有一位是低表明有鍵按下；接著所有列掃描線輸出低電位，再讀行值。 根據(jù)讀到的值組合就可以查表得到鍵碼。4x4鍵盤(pán)按4行4列組成如圖電路結(jié)構(gòu)。按鍵按下將會(huì)使行列連成通路，這也是見(jiàn)的使用者鍵盤(pán)設(shè)計(jì)電路。 //-----------4X4鍵盤(pán)程序--------------// uchar keboard(void) { uchar xxa,yyb,i,key; if((PINC&0x0f)!=0x0f) //是否有按鍵按下 {delayms(1); //延時(shí)去抖動(dòng) if((PINC&0x0f)!=0x0f) //有按下則判斷 { xxa=~(PINC|0xf0); //0000xxxx DDRC=0x0f; PORTC=0xf0; delay_1ms(); yyb=~(PINC|0x0f); //xxxx0000 DDRC=0xf0; //復(fù)位 PORTC=0x0f; while((PINC&0x0f)!=0x0f) //按鍵是否放開(kāi) { display(data); } i=4; //計(jì)算返回碼 while(xxa!=0) { xxa=xxa>>1; i--; } if(yyb==0x80) key=i; else if(yyb==0x40) key=4+i; else if(yyb==0x20) key=8+i; else if(yyb==0x10) key=12+i; return key; //返回按下的鍵盤(pán)碼 } } else return 17; //沒(méi)有按鍵按下 }
上傳時(shí)間： 2013-11-12
上傳用戶(hù)：a673761058
Single-Ended and Differential S-Parameters Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
上傳時(shí)間： 2014-03-25
上傳用戶(hù)：yyyyyyyyyy
電路板故障分析 維修方式介紹 ASA維修技術(shù) ICT維修技術(shù) 沒(méi)有線路圖,無(wú)從修起 電路板太複雜,維修困難 維修經(jīng)驗(yàn)及技術(shù)不足 無(wú)法維修的死板,廢棄可惜 送電中作動(dòng)態(tài)維修,危險(xiǎn)性極高 備份板太多,積壓資金 送國(guó)外維修費(fèi)用高,維修時(shí)間長(zhǎng) 對(duì)老化零件無(wú)從查起無(wú)法預(yù)先更換 維修速度及效率無(wú)法提升,造成公司負(fù)擔(dān),客戶(hù)埋怨 投資大量維修設(shè)備,操作複雜,績(jī)效不彰
上傳時(shí)間： 2013-11-09
上傳用戶(hù)：chengxin
題目：利用條件運(yùn)算符的嵌套來(lái)完成此題：學(xué)習(xí)成績(jī)>=90分的同學(xué)用A表示，60-89分之間的用B表示，60分以下的用C表示。 1.程序分析：(a>b)?a:b這是條件運(yùn)算符的基本例子。
上傳時(shí)間： 2015-01-08
上傳用戶(hù)：lifangyuan12
RSA算法 :首先, 找出三個(gè)數(shù), p, q, r, 其中 p, q 是兩個(gè)相異的質(zhì)數(shù), r 是與 (p-1)(q-1) 互質(zhì)的數(shù)...... p, q, r 這三個(gè)數(shù)便是 person_key，接著, 找出 m, 使得 r^m == 1 mod (p-1)(q-1)..... 這個(gè) m 一定存在, 因?yàn)?r 與 (p-1)(q-1) 互質(zhì), 用輾轉(zhuǎn)相除法就可以得到了..... 再來(lái), 計(jì)算 n = pq....... m, n 這兩個(gè)數(shù)便是 public_key ，編碼過(guò)程是, 若資料為 a, 將其看成是一個(gè)大整數(shù), 假設(shè) a < n.... 如果 a >= n 的話, 就將 a 表成 s 進(jìn)位 (s
標(biāo)簽： person_key RSA 算法
上傳時(shí)間： 2013-12-14
上傳用戶(hù)：zhuyibin
一個(gè)LCD燈的小程序。不是我寫(xiě)的。我只負(fù)責(zé)了調(diào)試。適用在ACEXEP1K30QC208-3上。我跑了SIMULATOR，管腳連接標(biāo)示了。我也下在電路板上試過(guò)了，沒(méi)有問(wèn)題。要用到實(shí)驗(yàn)板上的兄弟們把CLK1改到TESTOUT3或者0就好了。綫幫助新手，人人有責(zé)。
標(biāo)簽： SIMULATOR ACEXEP LCD 208
上傳時(shí)間： 2015-04-10
上傳用戶(hù)：330402686
數(shù)字運(yùn)算，判斷一個(gè)數(shù)是否接近素?cái)?shù) A Niven number is a number such that the sum of its digits divides itself. For example, 111 is a Niven number because the sum of its digits is 3, which divides 111. We can also specify a number in another base b, and a number in base b is a Niven number if the sum of its digits divides its value. Given b (2 <= b <= 10) and a number in base b, determine whether it is a Niven number or not. Input Each line of input contains the base b, followed by a string of digits representing a positive integer in that base. There are no leading zeroes. The input is terminated by a line consisting of 0 alone. Output For each case, print "yes" on a line if the given number is a Niven number, and "no" otherwise. Sample Input 10 111 2 110 10 123 6 1000 8 2314 0 Sample Output yes yes no yes no
上傳時(shí)間： 2015-05-21
上傳用戶(hù)：daguda
源代碼\用動(dòng)態(tài)規(guī)劃算法計(jì)算序列關(guān)系個(gè)數(shù) 用關(guān)系"<"和"="將3個(gè)數(shù)a，b，c依次序排列時(shí)，有13種不同的序列關(guān)系： a=b=c,a=b<c,a<b=v,a<b<c,a<c<b a=c<b,b<a=c,b<a<c,b<c<a,b=c<a c<a=b,c<a<b,c<b<a 若要將n個(gè)數(shù)依序列，設(shè)計(jì)一個(gè)動(dòng)態(tài)規(guī)劃算法，計(jì)算出有多少種不同的序列關(guān)系， 要求算法只占用O(n),只耗時(shí)O(n*n).
標(biāo)簽： lt 源代碼 動(dòng)態(tài)規(guī)劃 序列
上傳時(shí)間： 2013-12-26
上傳用戶(hù)：siguazgb
The government of a small but important country has decided that the alphabet needs to be streamlined and reordered. Uppercase letters will be eliminated. They will issue a royal decree in the form of a String of B and A characters. The first character in the decree specifies whether a must come ( B )Before b in the new alphabet or ( A )After b . The second character determines the relative placement of b and c , etc. So, for example, "BAA" means that a must come Before b , b must come After c , and c must come After d . Any letters beyond these requirements are to be excluded, so if the decree specifies k comparisons then the new alphabet will contain the first k+1 lowercase letters of the current alphabet. Create a class Alphabet that contains the method choices that takes the decree as input and returns the number of possible new alphabets that conform to the decree. If more than 1,000,000,000 are possible, return -1. Definition
標(biāo)簽： government streamline important alphabet
上傳時(shí)間： 2015-06-09
上傳用戶(hù)：weixiao99
電力系統(tǒng)在臺(tái)穩(wěn)定計(jì)算式電力系統(tǒng)不正常運(yùn)行方式的一種計(jì)算。它的任務(wù)是已知電力系統(tǒng)某一正常運(yùn)行狀態(tài)和受到某種擾動(dòng)，計(jì)算電力系統(tǒng)所有發(fā)電機(jī)能否同步運(yùn)行 1運(yùn)行說(shuō)明： 請(qǐng)輸入初始功率S0，形如a+bi 請(qǐng)輸入無(wú)限大系統(tǒng)母線電壓V0 請(qǐng)輸入系統(tǒng)等值電抗矩陣B 矩陣B有以下元素組成的行矩陣 1正常運(yùn)行時(shí)的系統(tǒng)直軸等值電抗Xd 2故障運(yùn)行時(shí)的系統(tǒng)直軸等值電抗X d 3故障切除后的系統(tǒng)直軸等值電抗 請(qǐng)輸入慣性時(shí)間常數(shù)Tj 請(qǐng)輸入時(shí)段數(shù)N 請(qǐng)輸入哪個(gè)時(shí)段發(fā)生故障Ni 請(qǐng)輸入每時(shí)段間隔的時(shí)間dt
標(biāo)簽： 電力系統(tǒng) 正 計(jì)算 運(yùn)行
上傳時(shí)間： 2015-06-13
上傳用戶(hù)：it男一枚
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