Operating System- CS604 Assignment # 4 Solution Fall 2010

Operating System- CS604

Assignment # 4

Solution

Fall 2010

                                                               Marks: 20

Due Date

Your assignment must be uploaded before or on 28^th Jan 2010.

Objective

The objective of this assignment is to familiarize with Memory Management.

Instructions

Ø  Avoid Plagiarism. No marks will be given in case of cheating or copying from the internet or from other students.

Ø  Submit the assignment through your account on VULMS. No assignment will be accepted through email after the due date.  

Ø  If you have any problem related to assignment, feel free to discuss it by email at cs604@vu.edu.pk

Question # 1

The logical address space of the process is 32 pages and the size of each page is 4 Kb. There are 256 frames in the main memory. The size of a frame is equivalent to the size of a page. With the given information, answer to the following questions:

• Calculate the size of Logical Address?
• Find the size of the Logical Memory?
• Calculate the size of Physical Address?
• Determine the size of the Physical Memory?

Solution:

Logical Address

Pages=32

No. of bits required for p = Log₂ [32] = 5 bits

No. of bits required for d = Log₂ [4 Kb] = Log [4096] = 12 bits

Size of logical address= 5 + 12 = 17 bits

Size of the logical memory:

No. of pages = 32

Size of each page = 4 Kb

Size of Logical Memory = No. of pages * size of each page

    = 32 * 4Kb

                                        =   128 Kb

Size of Physical Address

Total number of frames= 256

No. of bits required for f= Log₂ [256] = 8 bits

No. of bits required for d= Log₂ [4 Kb] = Log [4096] = 12 bits

Size of Physical address = 8 +12 = 20 bits

Size of Physical memory:

No. of frames= 256

Size of each frame= 4 Kb

Size of Physical Memory = No. of frames * size of each page

     = 256 * 4 Kb

                                        =   1024 Kb