Microprocessor And Interfacing - May 2016

Electronics and Comm. Engg. (Semester 4)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.

Short Questions

1(a) What is the use of bidirectional buffer in 8085?(1 marks) 1(b) Define the function of parity flag in 8085.(1 marks) 1(c) What is clock signal?(1 marks) 1(d) Define machine cycle.(1 marks) 1(e) Write instruction which rotate accumulator left with carry.(1 marks) 1(f) What is the value of SP after execution of PUSH D instruction. (SP=3000, DE=8050).(1 marks) 1(g) What is direct addressing mode? Give an example.(1 marks) 1(h) How many bytes instruction HLT has?(1 marks) 1(i) How many T-States are required for LXI instruction?(1 marks) 1(j) If memory has 8192 memory locations, then how many address lines are required?(1 marks) 1(k) If the memory size is 256 × 1 bits. How many chips are required to make up-to 1 Kbyte of memory?(1 marks) 1(l) What is the total number of T-States required to execute below program.
    MVI C,05H
Back: DCR C
    JNZ Back(1 marks) 1(m) Which interrupt has the highest priority?(1 marks) 1(n) Explain the instruction: EI(1 marks) 2(a) Describe the instruction with example and also show the contents of register/memory locations before and after execution of instruction: XTHL(3 marks) 2(b) Show the diagram to generate control signal using NAND gate in 8085.(4 marks)

Solve any one question from Q.2(c) & Q.2(d)

2(c) Write 8085 assembly language program for Modulo-10 down counter. After count 00H, the count should go back to repeat the sequence. Provide 1 Sec delay between count and display the count at an output port 01H. The clock frequency is 1 MHz. Show timing calculations assuming suitable value of T states for various instructions.(7 marks) 2(d) Write 8085 assembly language program to perform the following, a₂ + b₂ , where a and b are 8-bit binary numbers.(7 marks)

Solve any three question from Q.3(a), Q.3(b), Q.3(c) & Q.3(d), Q.3(e), Q.3(f)

3(a) Compare memory mapped I/O and I/O mapped I/O.(3 marks) 3(b) Show only memory map for the 8085 microprocessor such that it should contain 8 kbyte of EPROM and 8 kbyte of RAM.(4 marks) 3(c) Draw timing diagram for DAD instruction.(7 marks) 3(d) What is the difference between absolute decoding and linear decoding. Explain with example.(3 marks) 3(e) Draw memory system and show memory map for the microprocessor system such that it should contain 2 kbyte of EPROM and 2 kbyte of RAM with starting addresses 0000H and 6000H(4 marks) 3(f) Draw timing diagram for STA instruction.(7 marks)

Solve any three question from Q.4(a), Q.4(b), Q.4(c) & Q.4(d), Q.4(e), Q.4(f)

4(a) Draw control word format for Bit Set/Reset for 8255 IC.(3 marks) 4(b) Write a program to initialize 8255 in the configuration given below: Port A as simple input, Port B as simple output, Port C_L as output and Port C_U as input. Assume address of the control word register of 8255 as 83H.(4 marks) 4(c) Consider that 4 LEDs are connected to port C_L of 8255 chip. Address of port C is 82H and control register is 83H. Write a program to flash 4 LEDs 10 times. Assume persistence of vision to be 0.1 seconds. Consider operating frequency 2.5 MHz.(7 marks) 4(d) Draw control word format for I/O mode of 8085.(3 marks) 4(e) Write a BSR control word subroutine only to set PC7 and PC3 and reset them after 10ms delay. (do not calculate for delay)(4 marks) 4(f) Write a program to generate square wave using digital to analog converter 0808.(7 marks)

Solve any three question from Q.5(a), Q.5(b), Q.5(c) & Q.5(d), Q.5(e), Q.5(f)

5(a) State any three features of 8259 programmable interrupt controller.(3 marks) 5(b) What are the function of below pins of 8251 USART 1. DSR', DTR', RTS', CTS'.(4 marks) 5(c) Draw and explain the functional block diagram of 8253 timer IC.(7 marks) 5(d) State any three features of Intel 8086 Microprocessor.(3 marks) 5(e) What are the advantages of Memory segmentation in 8086(4 marks) 5(f) Draw and explain the functional block diagram of interrupt controller IC 8259.(7 marks)