CPSC 2105 Introduction to Computer Organization
Homework Set 2 Due Wednesday, April 4, 2007
NOTE: SHOW ALL OF YOUR WORK. YOU MUST DEMONSTRATE THAT YOU
UNDERSTAND THE PROCESS OF OBTAINING AN ANSWER. WHILE THESE CAN BE
DONE ON MANY CALCULATORS, YOU MUST DO THESE BY HAND.
DO NOT SHOW ANY WORK ON THIS QUESTION SHEET.
1. Use a 2–to–4 active–high decoder and an OR gate to implement the
exclusive NOR function F(X, Y) = NOT (X Y).
2. Use a 4–to–1 multiplexer to implement the same function.
3. Convert the following expression from reverse Polish (Postfix) notation to infix.
U V W X Y Z + * + * + Note that “*” denotes multiplication.
4. You are given the following memory map of a byte addressable memory.
Address FF 100 101 102 103 104 105 106 107 108
Contents 66 FF 55 BA D1 22 11 44 33 77
All values shown are hexadecimal. What is the hexadecimal value of the 32–bit integer
stored at address 104 if
a) The number is stored in big–endian form.
b) The number is stored in little–endian form.
5. You are given the following memory map for the MARIE, in which all addressable
items are 16–bit words.
Address: 0x105 0x106 0x107 0x108 0x109
Contents: 0xFAD 0x109 0x105 0xCAFE 0x77
What is the effect of the following instruction? What is placed in the accumulator?
a) LoadI 0x107 Immediate Addressing
b) Load 0x107 Direct Addressing
c) Load * 0x107 Indirect Addressing