UGC NET CSE | December 2015 | Part 3 | Question: 1

Question

The three outputs $x_1x_2x_3$ from the $8\times 3$ priority encoder are used to provide a vector address of the form $101x_1x_2x_300$. what is the second highest priority vector address in hexadecimal if the vector addresses are starting from the one with the highest priority?

• A. $BC$
• B. $A4$
• C. $BD$
• D. $AC$

Answer 1

prirority encoder 8x3 gives equivalent bits for digits from 0-7

given vector address 101 x1 x2 x3 00

first highest priority 101 0 00 00  i.e A0 (since vector addresses are starting from the one with the highest priority x1=x2=x3=0)

second highest priority  1010 0100 i.e A4 (x1=x2=0,x3=1)

so ans will be  B

Answer 2

1 0 1 X1 1 0 0 0

Answer 3

I think ans should be A8.

any comments....??

Comments

i also think the answer should be A8 because for highest priority x1x2x3=111

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no.

highest priority is 000.

2nd highest is 001

...

...

lowest is 111