Question
Download Solution PDFDirection: Given question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. You are to examine these two statements carefully and select the answers to these items using the codes given below.
Assertion (A): A de-multiplexer cannot be used as a decoder.
Reason (R): A de-multiplexer selects one of many outputs, whereas a decoder selects an output corresponding to the coded input.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFA is false but R is true. A demultiplexer can be used as a decoder.
Explanation:
Decoder:
Generally, a decoder converts a binary number into any other format (decimal, hexadecimal, etc)
Eg: 2 × 4 decoder
Truth table:
|
A |
B |
Y0 |
Y1 |
Y2 |
Y3 |
|
0 |
0 |
1 |
0 |
0 |
0 |
|
0 |
1 |
0 |
1 |
0 |
0 |
|
1 |
0 |
0 |
0 |
1 |
0 |
|
1 |
1 |
0 |
0 |
0 |
1 |
DeMUX: A demultiplexer takes a single input line and produces many output lines.
|
S1 |
S0 |
Y0 |
Y1 |
Y2 |
Y3 |
|
0 |
0 |
D |
0 |
0 |
0 |
|
0 |
1 |
0 |
D |
0 |
0 |
|
1 |
0 |
0 |
0 |
D |
0 |
|
1 |
1 |
0 |
0 |
0 |
D |
Now if we put input pin (I) of DeMUX remains at logic 1 and at select pin of DeMUX (S1, S0) we apply i / p (A, B) of decoder then DeMUX will be work as decoder. {I = 1}
Eg:
AB = 00 = S1 S0 ;
Y0 = 1 Y1 = 0 Y2 = 0 Y3 = 0
AB = 10 = S1 S0 ;
Y0 = 0 Y1 = 0 Y2 = 1 Y3 = 0
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