Download Final exam - Computer Architecture | CPSC 5155G and more Exams Computer Architecture and Organization in PDF only on Docsity! CPSC 5155 Introduction to Computer Architecture Final Exam Due Friday, May 4, 2007 THIS TEST IS OPEN-BOOK, OPEN-NOTES. DO NOT PUT ANY ANSWERS ON THIS PAPER. GOOD LUCK! 1. (20 points) Consider a computer in which all integers are stored as 8 bits. a) What is the range of integer values that can be stored in two’s–complement form; i.e. the most negative integer and the most positive integer. b) What is the range of integer values that can be stored for unsigned arithmetic. c) Perform the following sums assuming 8–bit binary arithmetic. Indicate the answer as “Overflow” if the sum cannot be represented. a) 120 + 130 (assuming unsigned arithmetic) b) 120 + 130 (assuming saturation arithmetic) c) 140 + 150 (assuming unsigned arithmetic) d) 140 + 150 (assuming saturation arithmetic) NOTE: You can answer this without doing any binary arithmetic. 2. (10 points) Draw the transition diagram for a modulo–3 down counter. 3. (10 points) Draw a circuit diagram to show how to implement a) a three-input OR gate using only two-input OR gates. b) a four-input OR gate using only three-input OR gates. 4. (10 points) Use a JK flip-flop and (possibly) a NOT gate to implement a) a D flip-flop b) a T flip-flop. 5. (20 points) A computer has a cache memory set–up, with the cache memory having an access time of 6 nanoseconds and the main memory having an access time of 80 nanoseconds. This question focuses on the effective access time of the cache. a) What is the minimum effective access time for this cache memory? b) If the effective access time of this memory is 13.4 nanoseconds, what is the hit ratio? 6. (20 points) Suppose a computer using direct mapped cache has 232 words of main memory and a cache of 1024 blocks, where each cache block contains 32 words. a) How many blocks of main memory are there? b) What is the format of a memory address as seen by the cache, that is, what are the sizes of the tag, block, and word fields? c) To which cache block will the memory reference 0000 63FA map? 7. (10 points) This is an unusual problem that will require some thought. There is nothing quite like it in the notes. You are given two Boolean equations, using logical OR, logical NOT, and logical AND. X + Y + Z = 1 Y Z = 1 Solve these for the values of X, Y, and Z.
