Hi,
Kindly guide me with the output of 2 2-bit comparators (i think its a 4-bit magnitude comparator) constructed by combing 2 xnor gates whose o/p is connected to a AND gate. When input 11 and 00 is supplied, i am getting 1 output though 11 and 00 are not same. Kindly guide me.

Zulfi.

 

Start with the boolean expression for your circuit. What is it?

 

Hi,
The expression can be:
(P1 xnor Q1) and (P2 xnor Q2)
The circuit is shown at:

www.up.edu.ps/upinar/moodledata/948/Lecture_13.ppt
​

Kindly guide me.
​

Zulfi.​

 

Now, what is another name for the XNOR gate? Specifically, it is HI when both inputs are ...?

In the example you started with, the four bits that were applied, 11 and 00, how did those four bits map to the two 2-bit numbers being compared?

 

what is another name for the XNOR gate? Specifically, it is HI when both inputs are ...?

Ans. When inputs are same. Sorry I dont know the other name (wiki says enor or exnor).

how did those four bits map to the two 2-bit numbers being compared?

Sorry. I dont understand this mapping term. 1100 is mapped to 11 xnor 00.

Kindly guide me.

Zulfi.

 

Ans. When inputs are same.

It is also known as the EQ, or EQUALITY, gate.

Sorry. I dont understand this mapping term. 1100 is mapped to 11 xnor 00.

Well, look at the slides that you linked. In particular, slide #6.

 

Okay. Thanks. I got it now. I should be:
comparing 00 & 11
so (0 xnor 1) and (0 xnor 1)= 0 (not same).

Thanks for your time.

Zulfi.