ACE test

Question

Qus 12. A magnitude comparator consists of inputs A[A3 A2 A1 A0] and B[B3 B2 B1 B0]. The total number of comparisons performed for A>B is ______________

Comments

A=4 bit , B=4 bit

no. of A=B => 2^4 = 16

total = 2⁴×2⁴ = 2⁸ = 256

Rest = toal - no. of a=b

= 256 - 16 = 240

So A>B = 240/2 = 120

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Please elaborate..how magnitude comparator works

if A3>B3 then A>B ...............................................................1 comparison

if A3=B3 but A2>B2 then A>b................................................2 comparison

if A3=B3 and A2=B2 but A1>B1 then A>B..............................3 comparison

if A3=B3 and A2=B2 and A1=B1 but A0>B0 then A>B.............4 comparison

                                                                           so TOTAL=10 comparisons

This approach is wrong?

Answer 1

maximum it will take 10 comparision .

http://www.electronicshub.org/digital-comparator-and-magnitude-comparator/