EC-501 Microprocessor and its Applications - May 2023 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aDraw and explain the architecture of 8086 microprocessor. Mention the task performed by BIU and EU.
   How to answer

   • Block diagram of 8086 showing BIU and EU components
   • Function of BIU: fetch, queue, address generation, bus control
   • Function of EU: decode, execute, ALU, registers, flags
   • Interaction via instruction queue
2. 7 Marks
   bExplain minimum mode of 8086 microprocessor. Draw and discuss the timing diagram of memory read cycle in minimum mode for 8086 microprocessor.
   How to answer

   • Minimum mode definition with MN/MX pin and single processor configuration
   • Control signals and bus structure in minimum mode
   • Timing diagram of memory read cycle with T1-T4 states
   • Address/data multiplexing, ALE, M/IO, RD, DEN, DT/R explanation
3. 7 Marks
   aWhat do you mean by addressing modes? Explain the addressing modes of 8086 microprocessor with example.
   How to answer

   • Definition of addressing mode
   • List of 8086 addressing modes
   • Example instruction for each mode
   • Effective address calculation
4. 7 Marks
   bDescribe the flag register of 8086 microprocessor.
   How to answer

   • 16-bit flag register layout with 9 active flags
   • Status flags: CF, PF, AF, ZF, SF, OF
   • Control flags: TF, IF, DF
   • Role of each flag with example
5. 7 Marks
   aWrite an assembly language program for 8086 microprocessor to add two 16-bit numbers.
   How to answer

   • Initialize data segment and pointers to operands
   • Load two 16-bit numbers, ADD then ADC for carry
   • Store result and handle carry
   • Flowchart and assembly listing
6. 7 Marks
   bWrite an assembly language program for 8086 microprocessor to find the largest number in an array of 10 numbers.
   How to answer

   • Initialize count, pointer to array and max variable
   • Loop with compare and update max using CMP and conditional jump
   • Decrement counter and repeat for 10 numbers
   • Store/display largest number
7. 7 Marks
   aDraw and explain the block diagram of 8255 (Programmable Peripheral Interface) IC in detail.
   How to answer

   • Block diagram: data bus buffer, control logic, ports A, B, C
   • Control word and mode selection: Mode 0,1,2 and BSR mode
   • Pin details and interfacing signals
   • Example initialization
8. 7 Marks
   bDraw and explain the block diagram of 8259A (Priority Interrupt Controller) IC in detail.
   How to answer

   • Block diagram: IRR, ISR, IMR, priority resolver, control logic
   • Interfacing with 8086 and cascading
   • Interrupt sequence and command words ICW/OCW
   • Priority modes
9. 7 Marks
   aDiscuss the different interrupts of 8086 micro processor.
   How to answer

   • Classification: hardware, software, internal/external, maskable/non-maskable
   • Dedicated interrupts: divide by zero, single step, NMI, breakpoint, overflow
   • INTR and NMI handling
   • Interrupt vector table
10. 7 Marks
    bWhat do you mean by absolute and partial decoding? Interface 32 KB of RAM with 8086 microprocessor.
    How to answer

    • Definition of absolute vs partial decoding with address lines
    • Address decoding logic for 32 KB RAM with 8086 odd/even banks
    • Circuit diagram using decoder and chip select
    • Advantages/disadvantages and aliasing
11. 7 Marks
    aExplain the architecture of 8051 micro-controller with neat and clean diagram.
    How to answer

    • Block diagram: CPU, RAM, ROM, timers, serial port, I/O ports
    • Memory organization and registers
    • Oscillator, control and bus structure
    • Neat labelled diagram
12. 7 Marks
    bDescribe the hardware and software interrupts of 8051 microcontroller.
    How to answer

    • List of 8051 interrupts: INT0, INT1, T0, T1, serial
    • Hardware vs software interrupts concept
    • Interrupt enable, priority and vector addresses
    • IE and IP registers
13. 7 Marks
    aDraw and explain the block diagram of 0808/0809 ADC. How is A/D converter interfaced with 8086. Explain in detail.
    How to answer

    • Block diagram of ADC 0808/0809: multiplexer, comparator, SAR, ladder
    • Pin details: address, ALE, SOC, EOC, OE
    • Interfacing circuit with 8086 using 8255 or bus
    • Timing and program steps for conversion
14. 7 Marks
    bExplain in detail about the SFR's in 8051 microcontroller.
    How to answer

    • Concept of SFR area and addresses 80H-FFH
    • List: ACC, B, PSW, SP, DPTR, P0-P3, IP, IE, TMOD, SCON etc.
    • Bit-addressability and function of each
    • Example usage
15. 14 Marks
    Write short notes of any two:

    1. a)Block diagram of 8254 (Programmable Interval Timer) IC
    2. b)Rotate and swap instruction of 8051 microcontroller.
    3. c)PSW register of 8051 microcontroller.
    How to answer

    • For chosen topics: block diagram/purpose and key registers
    • Operating modes/commands and control words
    • Interfacing or instruction examples
    • Applications