1. Detailed block diagram of a microcomputer system 2. What is the difference between an actuator and a sensor? Give an example of each. [4] 3. Discuss the bus activity for an opcode fetch cycle and show it diagram 4. What is the program status word of the following and the content of the accumulator after execution: a. Add 3CH and E6H b. Add 6AH and BAH C. Add 73H and 71H [4] [4] [4] [7] [7] 5. What is the difference between the 8051's idle mode and power-down mode? [4] 6. Write a subroutine called SUM that calculates the sum of two numbers in the accumulator A and the B register, and returns the answer in the accumulator, A. Then, write another subroutine called TOTAL that calculates the sum of three numbers in R1, R2, and R3. Do not subroutine to do the additions. Return the total sum in R5. use the ADD instruction in the TOTAL subroutine. Instead, you should call the SUM [6]