QUESTION $11.2.3.4.$ What is a central processing unit and d raw it diagram. Discuss the steps involved during fetching an instruction Draw the label diagram of the circuitry for I$/0$ ports. Discuss the difference between the power control registers. QUESTION $21.2.$ Discuss the program status word $[5].[5][6][4][5]$ You have R $=16$H and S $=7$CH$,$ write a code performing subtraction between them. Point out the program status word that Question $31.$ is $\backslash$ Draw the label diagram for the c are flagged during the operation. locking source $2.3.$ Write a program using Timer $0$ to create a $1$ kHz square wave on P$1\mathrm{.}0$ Draw the c ircuit Diagram for Interfacing of External Memory