Digital Electronics - Combinational Logic Circuits - Discussion
Discussion Forum : Combinational Logic Circuits - General Questions (Q.No. 4)
4.
For the device shown here, let all D inputs be LOW, both S inputs be HIGH, and the 
input be LOW. What is the status of the Y output?
Discussion:
19 comments Page 1 of 2.
SPS said:
7 years ago
It acts as MUX, here s0,s1 are select lines.
EN is high & when,
s0=0,s1=0-->It selects D0
s0=0,s1=1-->It selects D1
s0=1,s1=0-->It selects D2
s0=1,s1=1-->It selects D3
Since s0, s1=1. D3 is selected, which is low. Hence output Y is low.
EN is high & when,
s0=0,s1=0-->It selects D0
s0=0,s1=1-->It selects D1
s0=1,s1=0-->It selects D2
s0=1,s1=1-->It selects D3
Since s0, s1=1. D3 is selected, which is low. Hence output Y is low.
(5)
Shama said:
1 decade ago
Since both S1 and S2 are high and EN is low given but due to bubble in front of it it behaves as high. So in such a case value of d3 is considered for the output.
As value of d3 is low so value of output Y is also low.
As value of d3 is low so value of output Y is also low.
AJAY said:
4 years ago
As EN is low, but in the circuit, the bubble symbol is there, so the device is enabled. As S1, S0 both are high, so it's select D3 as output (which is also low). Therefore, the output of the circuit is low.
(7)
Nagaraj Hegde said:
1 decade ago
If enable is low we are taking that only that's why and the if S1=S2=1, d3 will be selected then d3=0 when the enable is low. So the output will be low only.
Sangee said:
1 decade ago
This is a multiplexer operation.
The multiplexer operation needs many number of input and one output. That is it needs 2^n input and it produce one output.
The multiplexer operation needs many number of input and one output. That is it needs 2^n input and it produce one output.
Sneha jose said:
1 decade ago
EN is low means ic is enabled. When s0, s1 are high, it selects d3 to output. Since d3 is low, output is low.
Akhilesh maurya said:
1 decade ago
Here, S1 and S2 are enabled i.e. both are at HIGH(1 1) state then D3 must be enable & D3 will be as output but all D are LOW so output is LOW(D3)
Jyoti said:
6 years ago
Here, EN is low which means the input at EN is low and so the output it is generating to the device is high as it is made using not gate.
(1)
Nitesh kumar said:
1 decade ago
d0 = d1 = d2 = d3 = 0;
s0 = s1 = 1.
For producing output en =0;
When s1 = s2 = 1.
Then d3 is selected.
Hence, y = d3s1s2 = 0;
s0 = s1 = 1.
For producing output en =0;
When s1 = s2 = 1.
Then d3 is selected.
Hence, y = d3s1s2 = 0;
(1)
ABHISHEK SHARMA said:
4 years ago
Let EN be a switch, how many and how low or high they are, if EN is switched of then it would definitely be LOW or SWITCHED OFF.
(4)
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