CSC 371
Homework 3

Assigned Oct. 4, due Oct, 18

Problems from Chapter 3 (arithmetic)

• Exercises 3.2.1 through 3.2.6 on integer arithmetic (use row a examples)
• Exercises 3.6.4 and 3.6.5 on Booth's algorithm for multiplication (use row a examples)
• Exercises 3.10.1 through 3.10.3 on interpreting bit patterns (use row a examples)
• Exercises 3.11.1 and 3.11.2 on floating-point formats (use row a examples)
• Exercises 3.13.1 through 3.13.3 on associativity (use row a)

Logic design problem

Use LogiSim to build and test a circuit that acts as a three-bit integer ALU (i.e. it operates on three-bit signed integers, in two's-complement notation, so the range of possible values is -8 to +7). It should be able to perform five two-input operations: AND, OR, ADD, SUB, and SLT, each producing a three-bit result. Since there are five operations, you'll need 3 bits of "opcode"; you may decide for yourself which 3-bit pattern corresponds to which operation. Don't worry about detecting arithmetic overflow.

You may use LogiSim's built-in AND, OR, NOT, NAND, NOR, XOR, and MUX gates, in single-output form; you may not use the built-in arithmetic gadgets, nor LogiSim's multi-output gadgets that stand for a bunch of components in parallel. You may want to build some simple gadgets (like a full-adder) of your own and use them as black-boxes in your main circuit.