How will you construct and test a serial adder-subtractor circuit using JK flip-flop and shift registers? Thank you in advance

 

This sounds more like a homework question so I have moved it to the Homework Help forum.

 

you dont say how many bits, or who to control the add / subtract.
one way is do a serial to paralell conversion, run the paralell trough a 74181 ( one for each 4 bits needed) and back to serial. the 74181 will add subrtract, shift and many other functions.

 

How will you construct and test a serial adder-subtractor circuit using JK flip-flop and shift registers? Thank you in advance

You need to show YOUR best effort to do YOUR homework. That will allow us to see what your approach is, what you are getting right, and where you are going off the rails. We can then offer suggestions to get you back on the right track.

The first step is you have to have a clear understanding of what the objective is at a level of detail that will let you draw a timing diagram showing all of the signals and what should happen at each clock pulse.