• Home
  • Tutorials
  • Interviews
  • Info Seed
  • Forums
  • Projects
  • Links
  • Contact Us
Digital Electronics
NUMBER SYSTEM
BINARY CODES
BOOLEAN ALGEBRA
K MAPS
COMBINATIONAL CKT
INTRODUCTION
ADDER
FULL ADDER(FA)
FA using HAs
BINARY ADDER
SERIAL ADDER
PARALLEL ADDER
CARRY LOOK AHEAD ADDER (CLA)
QUESTION (BCD to Excess-3 using ADDER)
SUBTRACTORS
FULL SUBTRACTOR
FS using HSs
MORE QUESTIONS
SEQUENTIAL CIRCUITS
TIMING CIRCUITS

 

Q- Draw the circuit to check a PALINDROME number of even bits.

Ans: Palindrome number (in bits) is the number which is same whether seen from the first and the last bit. E.g. 1001, 0110, 0000, 1111 in 4 bits

So to check this we need to have same value of bit at 1st bit and 4th bit, 2nd and 3rd bit position for a 4-bit number. For a 6-bit number we need to have same bits at 1st and 6th bit, 2nd and 5th bit, 3rd and 4th bit positions.

Hence to check whether bits in different pairs have same value we need to have XNOR gate and then AND them to see whether all pairs satisfy the condition.

So we have the general circuit as next:

 

We can verify this for a 4-bit number as done next.

 So K-map for that is as

And hence we see that we need to XNOR the corresponding bits and then take AND of all outputs of XNORs

 

previous next
| Copyright © 2009 exploreroots- All Rights Reserved | Disclaimer |