Help me with a Adder circuit

Thread Starter

yasthicklee

Joined Feb 6, 2010
7
Hello friends,
I am in need of a simple 2 4-bit adder in which the output shud be added with the input.
That is, it shud be capable of storing the output and use the same for the next add operation.And I shud supply only 1 4-bit as input.....
 

bertus

Joined Apr 5, 2008
22,290

Thread Starter

yasthicklee

Joined Feb 6, 2010
7
Yes friend,I too looked over there and I was failed.I could not find the same which i need....

I need a Adder where I shud give only one input.......And it shud be added with the previous value of the adder.And it shud work only once after a clock pulse...
 

bertus

Joined Apr 5, 2008
22,290
Hello,

That is why I gave you the other pages too.
You will need a register (memory) for the "old" value.
That is connected to the second value input of the adder.

Greetings,
Bertus
 

Thread Starter

yasthicklee

Joined Feb 6, 2010
7
Hello friend,I triend the adder circuit with the Shift register 74LS195N.But when i gave the clock pulse for the first time (3 as my input) it is working.But for the second clock pulse I could not get the 6 as output.But I am getting 1 and in third clock pulse I am getting 2 and then 0.

Help with the circuit.....
 

bertus

Joined Apr 5, 2008
22,290
Hello,

What are you using as an adder?
Take a look at the 74283 as adder.
The 74195 can be the resgister.

Greetings,
Bertus
 

bertus

Joined Apr 5, 2008
22,290
Hello,

You have turned the bits around on the adder.
Bit 1 => A (value 1)
Bit 2 => B (value 2)
Bit 3 => C (value 4)
Bit 4 => D (value 8)

Greetings,
Bertus
 

Thread Starter

yasthicklee

Joined Feb 6, 2010
7
But friend,even doing all the things i could not get the exact circuit functioning in the right way.....pls help to sort out off this simple circuit.
 
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