Digital Components - Multiplexers And Demultiplexers Flashcards
How many select lines do you have in a 1 of 4 mud?
2 select lines.
When. 0 0 is selected, output is D0
When 01 is selected, output is D1
When 10 is selected, outputs is D2
When 11 is selected, output is D3
What are the control inputs in a Quad 2 input mux?
You have an Enable and Data Select line.
When Enable is HIGH, data can pass through
When Enable is LOW, data cannot pass through
The opposite applies for the Enable with a bar on top, see page 99.
When data select is HIGH, the B inputs are selected
When data select is LOW, the A inputs are selected
What does the G denote in a Quad 2 input Mux?
The data select lines and data inputs are ANDed together
How do you make a 16 input MUX from an 8 input Mux?
4 bits are required to choose from 16 different inputs
The Enable (bared) is used as the MSB for the data select
S3 is LOw and S3 is HIGH
The selected data is passed through a negative OR onto the output line
How many select lines does an 8 input Mux have?
4
What is the point of the parity method?
To check for the correct number of 1s so as to minimize the chances of a bit error
Main difference between a Mux and Demux
Mux is multiple inputs to one output
Demux is one input to multiple outputs
When writing the output of a MUX or DEMUX, what is the general form and why?
General form: Data input S3 S2 S1 S0
E.g. DS3S2S1’S0’
In a MUX or DEMUX the corresponding data input must be shown as well
