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

How the system would work in real time- simulation, How the system would wo...

How the system would work in real time -  Sensors in/near road gather data (these can be infra-red/light sensors, pressure sensors, induction loops etc.) -data is generally num

What is instruction cycle, What is Instruction Cycle The simplest model...

What is Instruction Cycle The simplest model of instruction processing can be of two steps. The CPU reads /fetches instructions (codes) from memory one at a time and executes i

What is missing offset, Q. What is Missing offset? The xxxx in machine ...

Q. What is Missing offset? The xxxx in machine language for instruction at line 0010 is there since the assembler doesn't know DATA segment location which will be determined at

Describe the functions of an operating system, Question: (a) Software ...

Question: (a) Software may be categorized into System software and Application software. Differentiate between these two categories, using examples to support your answer.

Vector processing, Vector Processing  A vector is an ordered set of the...

Vector Processing  A vector is an ordered set of the similar type of scalar data items. The scalar item can be a floating point number, a logical value or an integer. Vector pr

Addressability of memory - computer architecture, Addressability: Loc...

Addressability: Location-addressable Each alone accessible unit of information in storage is chosen with its numerical memory address. In the modern computers, location-a

Weighted harmonic mean and geometric mean, Problem Show which of the w...

Problem Show which of the weighted arithmetic mean, geometric mean or harmonic mean, you would use in each of the following case. Justify your answer in each case. (a)

Show the steps of execution of instructions, Q. Show the steps of execution...

Q. Show the steps of execution of instructions? Fetch First Instruction into CPU: Step 1: Find/calculate the address of first instruction in memory. In this machine illust

Mac and llc, how can we improve the way LLC and MAC are used for LAN operat...

how can we improve the way LLC and MAC are used for LAN operation.?

Discuss on wbmp, Question 1 How to call a WML Script from a WML page Q...

Question 1 How to call a WML Script from a WML page Question 2 Discuss on the following WML Script data type Question 3 Discuss on the following WML script statements

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