chapter 1郑州大学汇编课件.ppt

Chapter 1 Representing Data in a Computer Main contents Common ways that representing data （数据）in microcomputer . Aims Introduce common ways that representing data in computer Binary numbers（二进制数） Hexadecimal Numbers（十六进制数） ASCII codes for characters (ASCII 代码） BCD codes Calculation of Binary （二进制计算） Change between Binary and Hexadecimal（二进制和十六进制之间的转换） Outcomes 1. Can convert among binary, decimal, and hexadecimal numbers. 2. Can differentiate（区分） and represent numeric and alphabetic information as integers, BCD, and ASCII data. 1.1 Binary and Hexadecimal Numbers Binary numbering System Hexadecimal numbering System Octal numbering System（八进制） Conversion of Integer between Binary , Hexadecimal and Decimal Decimal Number（十进制） Being used in our life Base 10 Example: 36864=3×104+6 × 103+8 × 102+6 × 101+4 × 100 Binary Number Being used in computer Represent data in bits Binary digits , zero(0)/one(1) Base 2 Example: 1101b=1*23+1*22+0*21+1*20 Conversion between Binary Number and Decimal Number Convert from Decimal To Binary Divide Decimal Number by 2(base of Binary),getting Quotient（商） and Remainder（余数） Remainder is the next digit(right to left); Example：5876 Convert from Binary to Decimal Multiply each bit by powers of 2 Example：1101110101b Hexadecimal Number Binary Number is difficult to be read and write Hexadecimal Number is a convenient representation of binary numbers Base 16 0~9 ,A,B,C,D,E,F Example：3B8E2H Conversion between Hexadecimal Number and Decimal Number Convert from Decimal To Hexadecimal Example:5876 Divide Decimal Number by 16(base of hexadecimal), getting Quotient and Remainder Remainder is the next digit(right to left); Convert from hexadecimal to Decimal Example:8EFh Multiply each bit by powers of 16 Conversion between Hexadecimal Number and Binary Number Convert from Hexadecimal To Binary Substitute four bits for each hex digit Padding with leading zeros as needed E.g. 8EFh Convert from Binary to Hexadecimal From the right, breakin