tags:
- ece230
- bsu
- school
- digital-systems
- electronics
- lecture
- notes
- fall-2024
source: https://boisestatecanvas.instructure.com/courses/34549/files?preview=16574050
created: 2024-09-09Multiplexer: A Selector Switch
What is a logic block?
A logic block is a unit that performs a specific logic function based on Boolean algebra.
What is a multiplexer?
A multiplexer is a selector switch.
What is a multiplexer analogous to in computer programming?
A multiplexer is analogous to an if-else statement in computer programming.
What is the symbol for a multiplexer?
The symbol for a multiplexer is:
What is the signal that controls the output of a multiplexer?
The signal that controls the output of a multiplexer is the control signal.
How to build a multiplexer
What is the circuit diagram for a multiplexer?
The circuit diagram for a multiplexer is:
What is the Boolean function for a multiplexer with
and as inputs, and as the control signal?
The Boolean function for a multiplexer withand as inputs, and as the control signal is .
What is it called when only one signal can pass through at a time?
When only one signal can pass through at a time, it is called exclusivity.
Compounding Multiplexers
How do you make a multiplexer that can pick between more inputs?
To make a multiplexer that can pick between more inputs, you cascade them.
Incompletely specified Functions
What do you do about input combinations that can never occur?
For input combinations that can never occur, you can assign whatever value you want to its output.
What symbol do you use to designate an output as one that can never occur?
The symbol you use to designate an output as one that can never occur is D.What do you call input combinations that can never occur?
Input combinations that can never occur are called Don't Care situations.
Incompletely specified functions are functions where some input combinations are impossible or irrelevant. When you create a Karnaugh map for an incompletely specified function, you can assign the value of the impossible or irrelevant input combinations as 1, 0, or d. You can assign whatever value you want to help simplify the function easier.
It's your call
What output value should you assign to input combinations that produce Don't Care situations?
The output value that you should assign to input combinations that produce Don't Care situations is one that minimizes the resulting circuit the most.
Applying Don't Care on K-map Properly
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