Arithmetic Logic Units
CSC 405
74_181
The 74LS181 Arithmetic Logic Unit
The 74LS181 Arithmetic Logic Unit (ALU) can perform all the possible 16 operations
on two variables and a variety of arithetic operations.
Features
Provides 16 arithmetic operations: add, subtract, compare, double,...
Provides all 16 logic operations of two variable: XOR, AND, NAND, OR,...
Full lookahead for high speed arithmetic operation on long words
74LS181 Function Table
74LS181 Logic Diagram
Lab Assignment 5
Design a test circuit for the 74LS181 to verify its functional characteristics for logic and
arithmetic operations.
Implement your circuit.
Develop a test set (table of sample inputs and expected outputs) for the logic operations
and the arithmetic operations in ripple-carry mode only.
Conduct the tests and record your results. Make notes of unexpected results.
Write a report that includes the following information:
a. An overview of the 74LS181 (1/2 page)
b. Your test circuit layout and description (1 page with diagram)
c. Your test set table with description and experimental data
d. A brief summary of your results including lessons learned.
e. Discuss how the 74LS181 could be used to implement the functions of the VSC.
Attach your lab preparation and notes to your report and submit by the last day of class.