i need to implement a circuit that inputs two 4bit numbers (y3 y2 y1 y0 x3 x2 x1 x0)
and it has an output of (c3 c2 c1 c0 s3 s2 s1 s0) where "c" is the carry
and "s" is the sum

i was given an example in which X=0101 (5) Y=1000 (8) and it outputs
S=1010 (10) and C=0011 (3)
5+8=13

i dont know what is the role of C and S
how do they split the numbers???

i was asked to implement it using two 4 bit adders

here is the answer:
http://s290.photobucket.com/albums/ll279/t...nt=IMG_8831.jpg

i cant understand this circuit
????????

 

That makes two of us. Whadya gonna do?

 

This four bit adder circuit... it accept binary input and provides BCD output?

 

I think your example is wrong. It certainly makes no sense to me.

 

Could it be doing excess 3 encoding?

 

If you line up X and Y there should be no carries.

 

how can you explain that
S binary column is bigger by 6 then DEC number
and when the DEC number goes bigger then 10
then it has "1" and a normal number
the dec number is supposed to equal to the binay
noy to be smaller by 6
???

and in the EX3 column we each number is bigger by 3 then DEC number
and when the DEC number is smaller then 10
we dont have another 4 bits
?????????