2013年5月21日 星期二

5/10 數位邏輯設計-2

卡諾圖

1.必須有個方格
2.相鄰兩項,其對應變數字母只有一個不同變化量
3.兩個相鄰 "1 " 會消去一個互補的變數
   四個相鄰" 1 " 會消去兩個互補的變數

兩個二元變數的卡諾圖







三個二元變數的卡諾圖











X
Y
Z
m0
X’Y’Z’
0
0
0
m1
X’Y’Z
0
0
1
m2
X’YZ’
0
1
0
m3
X’YZ
0
1
1
m4
XY’Z’
1
0
0
m5
XY’Z
1
0
1
m6
XYZ’
1
1
0
m7
XYZ
1
1
1


EX 積項之和

Σm(1,3,2,6,7)
X’Y’Z’+ X’YZ+ X’YZ’+ XYZ’+ XYZ
=Y+X’Z

卡諾圖







5/3 數位邏輯設計-1

邏輯閘


AND
OR
NOT
XOR

布林代數恆等式














2013年5月2日 星期四

4/26 Output輸出

Output 輸出
-->Data that has been processed into a useful form called information
Display Devices 顯示器
-->Output device that visually conveys information
-->Information on display device sometimes called soft copy

CRT Monitor 螢幕
-->Contains cathode-ray tube
-->Screen coated with tiny dots (consists of a red,blue,and green)of phosphor(磷) material
resolution 解析度
-->Sharpness and clarity of image
Video card(graphics card) 顯示卡
-->converts digital output from computer into analog video signal

Flat-Panel Displays (LCD monitor液晶螢幕)
-->Uses liquid crystal display
-->Take up less desk space than CRT monitor
-->EX.Notebooks ,Tablets PCs,PDAs,Smart phones
LCD work
-->Uses liquid compound to present information on a display

Printer印表機

printer
-->Output device that produces text and graphics on paper
-->Result is hard copy,or printout
-->主要可以分成 "撞擊式印表機" 與 "非撞擊式印表機"

撞擊式印表機 (impact printer)
是藉由撞擊色帶、色帶來進行列印。
-->forms characters by striking mechanism against inked ribbon that contacts paper
點陣式印表機 dot-matrix printer
-->Impact printer that produces printed images when tiny wire pins strike ribbon
行列式印表機(line printer)來進行大量列印

非撞擊式印表機(nonimpact printer)
-->forms characters and graphics without striking paper
噴墨印表機(ink-jet printer)
-相機印表機(photo printer)
雷射印表機(laser printer)
-->Typically costs more than ink-jet printer,but is much faster
熱感應式印表機(thermal printer)
-->Generates images by pushing electrically heated pins against heat-sensitive paper
繪圖機 (plotter)
-->Large-format printer

Speakers and Headsets
audio output device
-->Computer component that produces music,speech,or other sounds
-->Speakers and headsets are common devices

voice output
-->Computer talks to you through speakers on computer
-->Internet telephony allows you to have conversation over Web

Other Out Devices
傳真機(facsimile(fax) machine)
-->Device that transmits and receives documents over telephone lines
多功能印表機(MFP,multi-function peripheral)
-->Provides functionality of printer,scanner,copy machine, and fax machine

2013年4月27日 星期六

4/19 Input 輸入

Input 輸入

-->Data or instructions entered into memory of computer

Two types of input :  Data & Instruction


The Keyboard 鍵盤

The Keyboard
-->Typing area
-->Numeric keypad
-->Function keys,special keys that issue commands

Key combination










insertion point 游標
-->Blinking vertical bar that indicates where next character you type will display


Pointing Devices

mouse 滑鼠
-->Pointing device that fits under palm of hand

Other Pointing Devices

trackball軌跡球
touchpad觸控板 pointing stick
joystick搖桿
touch screen觸控式螢幕
graphics tablet繪圖板 stylus畫筆

Voice Input







MIDI(musical instrument digital interface)
-->External device, such as electronic piano keyboard, to input music and  sound effects

PDAs,Tablet PCs,and Smart Phones

Digital Cameras

digital camera
-->Allows you to take digital pictures
-->Images viewable immediately on camera














resolution
-->Sharpness and clarity of image
-->>The higher the resolution,the better the image quality,but the more expensive the camera

Video Input

video input
-->Process of entering full-motion images into computer
-->Video capture card is adapter card that converts analog video signal into digital signal that computer can use
-->Digital video(DV)camera records video as digital signals

PC video camera and Web cam
video conferencing 視訊會議
-->Two or more geographically separated people who use net work on Internet to transmit audio and video data

Scanners and Reading Devices


scanner 掃描機
-->Light-sensing device that reads printed test and graphics
OCR(Optical character recognition)光學字元辨識
-->讀取紙張文件中的字元
OMR(Optiacl-mark reader)光學記號閱讀機
-->讀取手繪的記號,例如小圓圈或矩形
bar code 條碼

Terminals

point of sale(POS) terminal
-->Records purchases processes credit or debit card,and updates inventory
automated teller machine(ATM)
-->Self-service banking machine that connects to a host computer through a network
smart display
-->Thin monitor that detaches from computer to function as portable wireless touch screen

Biometric Input

biometrics
-->Authenticates person's identity by verifying personal characteristic
ex.fingerprint scanner

2013年4月25日 星期四

3/29 The Components of the System Unit

System unit
--> Case that contains electronic components of the computer used to process data

Chips
-->Small piece of semi-conducting material on which integrated circuits are etched
-->Chips are packaged so they can be attached to a circuit board

Motherboard
-->Main circuit board in system unit
-->Contains adapter card,processor chip, and memory chips
-->Also called system board

Machine cycle
-->Four operations of the CPU comprise a machine cycle

FOUR STEPS
1.FETCH 擷取
2.DECODE 解碼
3.EXECUTE 執行
4.STORE 寫回

Pipelining 管線作業
-->CPU begins fetching second instruction 
before completing machine cycle for first instruction
-->Results in faster processing











Register 暫存器
-->Temporary high-speed storage area that holds data and instructions










Memory
--> Electronic components that store instructions, data ,and results
--> Consists of one of more chips on motherboard or other circuit board
--> Each byte stored in unique location called address, similar to seats on a passenger train

Random access memory(RAM) 隨時存取記憶體(又稱揮發性記憶體)
-->Memory chips that can be read from and written to by processor
-->Also called main memory or primary storage
-->Most RAM is volatile (揮發性), it is lost when computer's power is turned off
--> SRAM DRAM

Read-only memory (ROM) 唯讀記憶體
-->Memory chips that store permanent data and instructions
-->Nonvolatile memory, it is not lost when computer's power is turn off

Access time 存取時間
-->Amount of time it takes processor to read data from memory
-->Measured in nanosecond (ns)

記憶體 奈秒
硬碟     毫秒
記憶體速度快

2013年3月28日 星期四

3/22 錯誤更正漢明碼 CPU

錯誤更正漢明碼 16 bit






















CPU中央處理器英語Central Processing Unit縮寫CPU),是電子電腦的主要裝置之一。其功能主要是解釋電腦指令以及處理電腦軟體中的資料。電腦的可編程性主要是指對中央處理器的編程。中央處理器、記憶體輸入/輸出裝置是現代電腦的三大核心部件。20世紀70年代以前,中央處理器是由多個獨立單元構成。後來發展出由積體電路製造的中央處理器,微處理器中央處理器複雜的電路可以做成單一微小功能強大的單元。

控制單元 4 STEPS
擷取(Fetch) --> 解碼 (Decode)--> 執行(Execute) --> 寫回(Store)

Pipelining 管線作業 in fast processing

1.算術邏輯單元(ALU)
在多數情況下,真正負責執行指令的是CPU的算術邏輯單元(ALU)。
2.匯流排單元
負責CPU與記憶體之間的溝通。
3.預先擷取單元
負責告訴匯流排單元到哪個記憶體位置讀取指令,而且他不僅會擷取下一個要執行的指令,而且她不僅會擷取下一個要執行的指令,還會擷取後續的其他指令,以確保要執行的指令都已經準備好了。
4.解碼單元(decode unit)
負責從預先擷取單元取得要執行的指令,並轉譯成CPU內部可以處理的形式。他會在控制單元中找尋要完成目前指令所需要的步驟。


 

2013年3月25日 星期一

3/15 計算機組織與結構效能設計 -浮點數



ALU的輸入和輸出











取負數
.-128 = 10000000
.取補數01111111
.LSB加一   +1
.結果  10000000
.所以 -(-128) = -128 (x)



浮點數表示法

符號 (S)
(0,1)
(
+,-)
偏移指數(E)
8 bits
真實指數=偏移指數 - 127
有效數(F)
23 bits

ex.