Hello friends, here I m going to how to design a circuit in OrCAd. I m going to design a half adder and subtracter. Which work both one by one according to enable input. Here I m select one enable input which select the desire operation either half adder or either half subtracter . When enable input is zero the circuit work as half adder . If It has value 1 it work as half subtracter.

Firstly, click on start button and then click on

OrCAD capture CIS

Then click on File and then NewProject and

then clickClick

Give

it n

ame

half

adde

r Ad

der

and

subt

Give location to save it

Click OK

Select Create a blank project

Clic

k O

K

After doing this a blank window is open and its used to design any circuit.

Clic

k on

pla

ce p

art

After click on place part a cascade window of place part is open as shown in fig.

Type

IC n

o. 7

486

This IC is of XOR gate

Draw the XOR gate on the page and connect with wire Select w

ire from here

Insert the AND gate and connect with wires

Type 7408

7408 IC is of AND gate

After this we have to connect digital clock

Type Digclock

Digital clock

Now connect the output probe and change its name Sum/Sub and carry/borrow

Click on place port

Select PORTLEFT-L

clickOK

Change the name of the output ports to SUM/SUB and

CARRY/BORROW

Output port Sum/Sub

Output port Carry/Borrow

Now the design of circuit is complete and now we have

to check the DRC

Select project manager

Select page1

Select pspice and then New simulation

Give it any nameClick Create

Set run to time to 10 micro sec.

Click OK

Now everything is complete and now run the circuit

Click on play button

After click on play button a blank black window is open and we have to Add traces to take output

Select Add trace

Click OK

Output waveform

Thank YouBy: Avtar Singh 3rd yr (ECE)UCoE, Pbi. Uni. Patiala