Computer Organization and Architecture

Name:____________________________

CMIS 310 – Spring 2013

HOMEWORK #3 – Week 3

This homework is worth 10% of your course grade and contains eleven questions worth a total of 106 points. 

Submit the completed assignment via your Assignment folder in our Tycho classroom, hard copy through US Mail, or electronic mail.   Mailed copies should be sent to:

Richard Daumit

5450 Whitley Park Terrace #512

Bethesda, MD 20814-2055

1.      (20 points) A 32-bit computer has two selector channels and one multiplexor channel. Each selector channel supports two magnetic disk and two magnetic tape units.  The multiplexor channel has two line printers, two card readers, and five VDT terminals connected to it.  Assume the following transfer rates.

            Disk drive                               700 Kbytes/s

            Magnetic tape drive                200 Kbytes/3

            Line printer                             6.6 Kbytes/s

            Card Reader                            1.2 Kbytes/s

            VDT                                        1 Kbytes/s

Estimate the maximum aggregate I/O transfer rate in this system.    

2. (20 points)  Given the following set of events, show which routines the CPU is executing for times 0 to 100 ns.  Each handler routine (with its interrupt request) takes 20 ns to complete.  The priority of the interrupts ranges from IRQ6 as the highest priority interrupt to IRQ0 as the lowest priority interrupt.

            Time                Action

            0 ns:                 Start of Main Program

            10 ns:               IRQ1

3.   (20 points) Create a page translation table the meets the requirements of the virtual memory system shown below.  Assume page (and frame) sizes of 20 with pages 0 through 3 in logical memory and frames 0 through 7 in physical memory.

      (Hint: Similar to Self-Assessment Question 7)

                                 Logical Memory                        Physical Memory

                                                                                                                 160

4.   (20 points) A computer system with 16K of memory, a Memory Management Unit with a page size of 2000, and the following page translation table:

(Note: All numbers are in hexadecimal, NOT decimal)

a.            Indicate the physical memory location corresponding to logical address 2210. 

b.         Indicate the logical address corresponding to physical memory location 41B55. 

5.   (2 points) The least efficient type of I/O is ________.

a)      Direct Memory Access (DMA)

b)      Programmed I/O

c)      Programmed I/O with Interrupts

6.  (2 points)The most efficient type of I/O is ________.

a)      Direct Memory Access (DMA)

b)      Programmed I/O

c)      Programmed I/O with Interrupts

7. (2 points)“Printer ready for more data” would trigger a(n)  ___________.

a)      External event interrupt

b)      Event completion interrupt

c)      Time allocation interrupt

d)     Abnormal event interrupt

8.  (2 points) End of allocated time for a block of execution would trigger a(n)  _____.

a)      External event interrupt

b)      Event completion interrupt

c)      Time allocation interrupt

d)     Abnormal event interrupt

9.   (6 points) Answer the following statements as True/False

a)      _______ DMA allows the CPU to perform other tasks during I/O transfer.           

b)       _______DMA provides for high-speed data transfer

      c)   _______ DMA can transfer only in one direction.

10.   (8 points) Match the descriptions below with the most appropriate memory management scheme (A through D).  Answers may be used once, more than once, or not at all.

            A.        Fixed-partition multiprogramming

            B.        Single task or uniprogramming system

            C.        Variable-partition multiprogramming

            D.        Virtual memory systems

_____________ a) allows program to exist in non-contiguous locations

_____________ b) contiguous allocation of memory where holes are created as programs are moved in and out of memory

_____________ c) not capable of multitasking

_____________ d)  size is limited by the addressing scheme and the amount of auxiliary storage,  rather than the size of main memory

11.   (4 points) In a paged system each logical block is called a(n)  _______, and the corresponding physical block is called a(n) _______.