PAI... is the toughest subject you people will ever face in the entire Second year. I would say , this subject would ruin your life...if you keep it for the last moment. It contains 4 units of Microprocessor and 2 units of Micro- Controller. Both are totally different concepts.
This subject wont let you score.With all your hard work you can score 60(max- and only if you are lucky enough). Rest you can hope for the best.

Books - Please dont think about any of the reference if you dared to think about it...
I would say...it is totally on your path to take a risk or not!!..... Going for a reference book would make it all the way more complicated!!

I would say - first 4 units from Techmax and last 2 from technical (from Kenneth Ayala .. which is the reference book for microcontrollers)

These books would suffice you more than enough...............

Download E-Books for Microprocessors 8086 and 8088:

Introduction to
Microprocessors and Microcontrollers

John Crisp