How to build a 4 bit 2's complement number using 2:1 mux?

[research_vlsi]

Hi friends

can u help me solving this digital question

To built an 4 bit 2's complement number using 2:1 mux?

thanks::::

 

[xstal]

Re: digital question

If you know that a 2:1 Mux can be used as a universal gate and also if you know how to design two's complement circuit, then there should not be any problem.
Now you have sufficient hint.You try it of your own.

Good Luck.

 

[research_vlsi]

Re: digital question

Hi

The hint given by you is good. I work it and find the answer.

I have another Question

1.How to detect a sequence of "1101" arriving serially from a single line?

2.How to detect if two 8-bit signals are same?

Regards...

 

[yasser_shoukry]

digital question

I think these two questions can be answered in the same manner.
To compare any two signals , just use XOR gates then OR the output of the XOR gate. If the final output is 0 then the two signals are the same.

 

[xstal]

Re: digital question

Hi

The hint given by you is good. I work it and find the answer.

I have another Question

1.How to detect a sequence of "1101" arriving serially from a single line?

2.How to detect if two 8-bit signals are same?

Regards...

Draw a state diagram for a sequence detector (overlaping or non-overlaping). The state diagram can be made either for mealy machine or moore machine. Then write a code for the state diagram.
I dont want to spoon feed you dear. I have given you proper hints. Please go through the books and learn it by yourself. These are very basic things. I think Moris Mano has explained sequence detector.

Good Luck

 

[research_vlsi]

Re: digital question

Thank u for the information dears...

regards;

 

[vikram161]

Re: digital question

Hi friends

can u help me solving this digital question

To built an 4 bit 2's complement number using 2:1 mux?

thanks::::

 

[richardyue]

digital question

What is two's complement number?

 

[research_vlsi]

Re: digital question

Hi friends,

I got a solution for the question, To built 4 - bit 2's complement number using minimum number of 2:1 Mux.

First I found the boolean equation's using K'Map. The equations are
If A,B,C,D are inputs and W,X,Y,Z are outputs

W=A xor (B+C+D)
X=B xor (C+D)
Y=C xor D
Z= D

After that I implemented these equation using 2:1 mux, I got 5 mux's.

If any body have solution to reduce the no: of mux.ie, below 5 mux.

Regards...

 

[haneet]

Re: digital question

richard two's complement number is a representtion of any negative binary number.
i hope u know wht is 1's complement. just take a negative number's 1's complement and then add binary 1 to it. the number deduced is a two's complement of the original number.
for more u an refer any digital book. best would be book by Morris Mano

 

[caplash_vlsi]

Re: digital question

any sequence for that matter "1101" can be detected using finite state machines;mealy or moore.....u can know bout these fsm's in any basic digital book.....