Flowchart: Alternate Process: SEPTEMBER 2010Time: 3 Hours Max. Marks: 100



      Question 1 is compulsory and carries 28 marks. Answer any FOUR questions from the rest. Marks are indicated against each question.

      Parts of a question should be answered at the same place.





Q.1 (74)

a. What are the advantages of a RISC processor?

b. Give the truth table for Y = Σ (m0, m3, m6, m9, m12, m15) + Σd (m5) and give its expression in maxterm form (Product of sum).


c. Explain error correcting & error detecting codes.


d. What do you understand by BCD code? Represent 163 in binary code and in BCD form.

e. Explain briefly DMA based transfer.

f. What is segment addressing?


g. What is the need for a cache memory? Where is it located in a computer?



Q.2 a. Discuss the concept of virtual memory and its mapping techniques.

b. A task can be carried out with a six stage pipeline with clock cycle of 10ns.The same task can be done in a non pipeline unit in 50ns. Determine the speed up ratio of the pipeline for 100 tasks. What is the maximum speed up that can be achieved? Determine the number of clock cycles it takes to process 200 tasks? (10+8)

Q.3 a. A program repeatedly execute a loop that has 120 iterations. Each iteration takes 10,000 cycles. On a multiprocessor system 50,000 additional cycles are enquired to synchronise the processor once all iterations of the loop have completed.


(i) What is the execution time of each loop on a uniprocesser system?

(ii) What is the execution time of each loop on a 2- processer system and the speed up over the uniprocesser system?

(iii) What is the execution time of each loop on a 4- processer system and the speed up over uniprocesser system?


b. Discuss cache coherence and its hardware and software oriented solution in a shared memory system. (8+10)


Q.4 a. Discuss different types of serial & parallel data communications used in computer systems.

b. Explain the following terms:-

(i) Transparent mode DMA operation.

(ii) Interrupt service routine. (10+8)


Q.5 a. Use booth multiplication algorithm to multiply 15 with 9. Show all the steps.

b. Explain the following terms:-

(i) Memory interleaving.

(ii) Semi conductor static memory cell. (10+8)

Q.6 a. Explain with the help of a diagram the functioning of a microprogram sequence for a control memory.


b. What is the need for page replacement policy in memory management system? Briefly describe 3 page replacement policies. (10+8)


Q.7 a. State the RTLs for fetch and decode cycle. Give the common bus architecture to implement above RTLs.


b. Present the hardware realization of a BCD subtractor. (10+8)