اسئلة واجوبة لسنوات سابقة   أستــاذ المــادة  احمد محمد حسين الغزالي   تـاريـخ النشــر   10/01/2017   الاجوبة النموذجية لامتحان المد الاول Q1/ 1-            Calculate the addition of the two numbers +28 and (- 29) which are represented using 6 bits, base 2 in the 2’s complement format                         011100  (28)                011101   (29)                100010                          1 +                100011    (-29)                 011100     + (+28)                 111111     (-1) 2-            Represent the decimal values (26), (-123) as signed, 7-bit numbers using each of the following binary formats:                                                                                                       a.      Signed and magnitude. b.     1 s complement. c.      2 s complement. (26) a.   0-11010 b.   0-11010 c.   0-11010 (-123) a.      1-1111011 b.     1-0000100 c.      1-0000101   3.             What are the main advantages of the 2’s complement representation over the 1’s complement and sign/magnitude? The advantage of the sign 2’s complement representation over the 1’s complement and sign/magnitude is that it contains only one type of zero while the other representations have both a +0 and -0. And the other is that addition of 2’ complement numbers can be performed without regard for the sign.’   4.            CPU operations can be divided into four basic steps, enumerate and explain each step briefly. CPU operation can be divided into four basic steps, namely, fetch, decode, execute and writeback. 1.            During the fetch step, the processor retrieves program instructions from memory. 2.            In the decode step, the instruction is broken down into parts. The instruction set architecture of the CPU defines the way in which an instruction is decoded. 3.            In the execute step, CPU performs the operation implied by the program instruction. 4.            During the writeback step, the CPU writes back the results of execution, to the computer s memory.   Q2/ 1.     B. 2.     D. 3.     A. 4.     C. 5.     C. 6.     B. م.م. احمد محمد حسين استاذ المادة