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

Static memories - computer architecture, Static memories Circuits c...

Static memories Circuits capable of receiving their state as long as power is applied volatile Static RAM(SRAM)

What is small computer systems interface, Q. What is Small Computer Systems...

Q. What is Small Computer Systems Interface? The other well-liked way is to connect a disk drive to a PC by a SCSI interface. Common drive choice for high-end workstations or s

What types of calendars can you create with google calendar, What types of ...

What types of calendars can you create with Google Calendar? Personal calendars, like default calendar Public calendars, which others can access through the web

An example of the subscriber traffic in erlangs, A subscriber makes three p...

A subscriber makes three phone calls of 3 minutes, 4 minutes and 2 minutes duration in a one hour period. Calculate the subscriber traffic in erlangs, CCS and CM. Subscriber tr

How are control signals achieve the particular operation, Q. How are contro...

Q. How are control signals achieve the particular operation? The control signals are applied directly as binary inputs to the logic gates of the logic circuits. All these input

Explain hardwired control organization, Q. Explain Hardwired control organi...

Q. Explain Hardwired control organization? In the hardwired organization control unit is designed as a combinational circuit. The control unit is applied by gates, flip-flops,

Define the while loop, The while Loop The while loop repeats a statemen...

The while Loop The while loop repeats a statement until the test at the top proves false. As an example, here is a function to return the length of a string. int string_leng

State in brief about virtual memory, What is Virtual memory The term v...

What is Virtual memory The term virtual memory signifies something that appears to be present though actually it is not. Virtual memory technique enables users to use more mem

Challenges in changing information technology, Q: Challenges and Prospects ...

Q: Challenges and Prospects in Changing Information Technology? There is no doubt that information technology has made significant progress during the past two decades. Modern

Example of a router connects to at most networks, A router connects to at m...

A router connects to at most K networks. How many routers R are required to connect to N networks? Derive an equation that gives R in terms of N and K. If N K and K >=2 this

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