Explain about 4-bit adder-subtractor circuit, Computer Engineering

Assignment Help:

Q. Explain about 4-bit adder-subtractor circuit?

Subtraction operation on binary numbers can be obtained by succession of addition operations only it implies that to achieve subtraction A-B we can find 2's complement of B. This can be computed by 1's complemented and then adding 1 to it. So a common circuit can carry out addition and subtraction operation. A 4-bit adder subtraction circuit is displayed in figure below that is formed by employing XOR gate with each full adder. XOR gate with output 0 is for inspecting overflow.

2153_Explain about 4-bit adder-subtractor circuit.png

Figure: 4-bit adder-subtractor circuit

Control input 'x' controls operations it implies that if x =0 then circuit acts as an adder and if x =1 then circuit acts as a subtractor. The operation is summarized as below:

a. When x = 0, c = 0, output of all XOR gates would be same as corresponding input Bi where i = 0 to 3. So Ai and Bi are added by full adders providing Sum Si and carry Ci .

b. When x = 1 output of all XOR gates will be complement of input Bi where i =0 to 3 to that carry C0=1 is added. So circuit finds A plus 2's complement of B which is equal to A-B.


Related Discussions:- Explain about 4-bit adder-subtractor circuit

C++, Byteland county is very famous for luminous jewels. Luminous jewels ar...

Byteland county is very famous for luminous jewels. Luminous jewels are used in making beautiful necklaces. A necklace consists of various luminous jewels of particular colour. Nec

General considerations for research -artificial intelligence, General Consi...

General Considerations for Research -artificial intelligence: If we can specify the initial state, the operators or a consumer and the goal check for a search problem, that al

Mutation - canonical genetic algorithm, Mutation: However it may appea...

Mutation: However it may appear that the above recombinations are a little arbitrary that especially as points defining whether crossover and inversion occur are chosen random

Define mfc, Define MFC. To accommodate the variability in response time...

Define MFC. To accommodate the variability in response time, the processor waits unless it receives an indication that the requested read operation has been done. The control s

What are the different pascal standards, The original Pascal standard was a...

The original Pascal standard was an unofficial standard documented by the author, Nicklaus Wirth, in "The Report". The first official standard was ISO 7185 issued in 1983. This was

Can we use write statements in screen fields, Can we use WRITE statements i...

Can we use WRITE statements in screen fields? If not how is data transferred from field data to screen fields? We cannot write field data to the screen using the WRITE stateme

Authentication verses firewall, How does an authentication system be differ...

How does an authentication system be different from a firewall into functioning? Authentication verses firewall User Authentication and Authorization A significan

Describe the operation of voltage to frequency ADC, Describe the operation ...

Describe the operation of voltage to frequency ADC. Ans: A voltage-to-frequency converter i.e. VFC is an oscillator that frequency is linearly proportional to a control volt

Stack, The Stack A procedure call is supported by a stack. So let's dis...

The Stack A procedure call is supported by a stack. So let's discuss stack in assembly. Stacks are 'Last In First Out' data structures and are used for storing return addresses

Which one is better hardware or software firewall, Which one is better hard...

Which one is better hardware or software firewall While deciding whether to buy a hardware or software firewall, the user must consider important factors such as performance an

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd