Universal Gate

[tech_vaibhav_eee]

Hi,
This was one of the questions asked to me during an interview. If anyone knows the answer, please reply.

Which of the following can behave as a universal gate:

1) Xnor + invertor
2)And + or

 

[dougy83]

Well, is it possible to implement an inverting gate (NOR NAND NOT) with noninverting gates (AND OR)? If you can answer that, you might be able to rule out one of the two choices.

 

[kamdy]

None of them are universal gate. a NAND gate is considered as universal gate because all other gates may be constructed using it

 

[thecritic]

Nand and NOR are universal Gates. I don't think you can make even a simple OR gate using XNOR and Inverter. Similarly, you can't even make an inverter using AND and OR. So neither of the options is correct answer.

 

[crutschow]

I agree. Neither option can be used as a universal gate.