Counter

Question

For a Mod-10 counter, Jhonson counter uses X FF′s, ring counter uses y FF′s, and ripple counter uses Z FF′s. Then X + Y + Z will ________.

Comments

19 ??

Answer 1

For above we need to keep in mind 3 things.If n is the number of flip flops used , then :

a)Mod value of ring counter  =   n  

So if mod value is 10 , then no of flips used in ring counter = y = 10

b) Mod value of Johnson's Counter = 2n

So if mod value is 10 , then no of flip flops is Johnson's Counter  =  10 / 2 =   x  =  5

c) Mod value of Ripple Counter  ranges from 2^n-1  + 1  to  2^n.This functionality is achieved through connecting appropriate flip flops to NAND gate.

So if mod value is 10 , so no of flip flops required =  z  =  4 [ By connecting Q₃  and  Q₁  to NAND gate , we achieve mod value = 10 which is less than 16]

Therefore, 

x + y + z   =   5 + 10 + 4

                =   19

Hence 19 is the final answer.

Comments

thnx habib verified :)