EE3404 Microprocessor and Microcontroller Important Questions

EE3404 Microprocessor and Microcontroller

Important Questions

Unit 1

1. The instruction code 01001111 (4FH) is stored in memory location 5005H. Illustrate the data flow with appropriate sketch and list the sequence of events when the instruction code is fetched by the 8085 MPU.
2. Two machine codes 00111110 (3EH) and 00110010 (32H) are stored in memory locations 8000H and 8001H, respectively. The first machine code (3EH) represents the opcode to load a data byte in the accumulator, and the second code (32H) represents the data byte to be loaded in the accumulator. Illustrate the bus timings as these machine codes are executed. Calculate the time required to execute the Opcode Fetch and the Memory Read cycles and the entire instruction cycle if the clock frequency is 2 MHz.
3. With a neat sketch, briefly explain the interrupt structure of 8085 microprocessor.
4. Draw and explain the timing diagram of CALL instruction in 8085 microprocessor.
5. Explain the software and hardware interrupts available in 8085 along with their vector addresses.
6. Draw and explain the timing diagram of (i) Memory read machine cycle and (ii) Memory write cycle of 8085.

Unit 2

1. Load the bit pattern 91H in register B and 87H in register C. Mask all the bits except DO from registers B and C. If DO is at logic 1 in both registers, turn on the light connected to the DO position of output port 01H; otherwise, turn off the light.
2. Define addressing modes. Also, comment on the addressing modes supported in 8085 microprocessor with suitable examples.
3. Write instructions to clear the CY flag, to load number FFH in register B, and increment (B). If the CY flag is set, display 01 at the output port; otherwise, display the contents of register B. Explain your results.
4. Write a subroutine to set the Zero flag and check whether the instruction JZ (Jump on Zero) functions properly, without modifying any register contents other than flags.
5. ) Illustrate the contents of the stack memory and registers when PUSH and POP instructions are executed, and explain how memory pointers are exchanged.
6. Write an assembly language program to perform bubble sorting operation.
7. List and define the addressing modes supported by 8085 microprocessor with examples.
8. State the data manipulation instructions in 8051 microprocessor and mention their functions.

Unit 3

1. Discuss in detail about the various modes and operation of the programmable timer 8254 when it is interfaced with the 8085 processor.
2. ) Discuss in detail about the various modes of operation of the 8279 with various functional blocks and the control word registers.
3. With a neat circuit diagram/functional block diagram, interface an analog sensor with 8085 microprocessor. Also, write an assembly language program to read, convert the sensor value and save the result in 8000H.
4. Briefly explain the different modes of operation in 8254 IC? Support the answer with appropriate timing diagrams.
5. With neat diagram, Explain the architecture and interfacing of 8255 PPI.
6. Draw the internal block diagram of 8279 keyboard display controller and explain its features.

Unit 4

1. Explain the various operating modes of 8051 timer and special function registers associated with timer/counter.
2. Explain the structure of port 0 and port 3 of 8051 microcontroller.
3. Briefly explain the methodology of interfacing and configuring an external memory with 8051 microcontrollers.
4. Discuss in detail about timer mode and control operations of 8051 microcontrollers with the relevant special function registers.
5. Discuss in detail about the methodology involved in configuration, Data transmission and reception via UART module in 8051 microcontroller. Assume a crystal oscillator of 11.059 MHz is connected to a microcontroller for achieving 19200 baud rate. Also, calculate the value of TH1 to be loaded in order to achieve the desired baud rate. Support the data transmission and reception part via assembly language programming.
6. With a neat circuit diagram and assembly language program, briefly explain the process of interfacing a unipolar stepper motor with 8051 microcontroller in 4-step sequence/bi- phase mode..

Unit 5

1. With a neat sketch, describe the features and architecture of PIC16F877 microcontroller.
2. With a neat sketch, detail the interrupt structure supported in PIC16F877 microcontroller.
3. Draw the architecture and list the major functional elements of PIC microcontroller.
4. Mention the instructions of PIC microcontroller and their functions.
5. With a neat sketch, detail about the different functional blocks available in a PIC16 series of microcontrollers.
6. Briefly explain the process of configuring and programming the external interrupts in PIC16 Series MCU. Illustrate it with a real-time example.