Gujarat Technological University 2010-4th Sem B.E Computer Science and Engineering e- -(Microprocessor and Interfacing) - Question Paper

GUJARAT TECHNOLOGICAL UNIVERSITY

B.E. Sem-IV exam June- 2010

Subject code : 140701

Subject Name: Microprocessor and Interfacing

Date: 17 / 06 /2010 Time: 10.30 am – 01.00 pm Total Marks: 70

Instructions:
1. Attempt all ques..
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.

Q.1
(a) (i) a few of the pins of 8085 are listed beneath. For every pin (line) show whether
it is an input line or output line and mention its function. ( Any 4 )(06 Marks)
(1) ALE (2) HOLD (3) SID (4) READY (5) TRAP

(ii) The memory address of the last location of a one K byte memory chip is
provided as FBFF H. Specify the memory map.(01 Marks)
(b) (i) discuss the subsequent instructions of 8085. Also mention about the
addressing mode and flags the instruction affects. ( Any 4 )(06 Marks)
(1) LHLD 1000H (2) RAL (3) DAD D (4) PUSH PSW (5)PCHL
(ii) What is meant by Bus ? Why is the address bus unidirectional and the data
bus bidirectional ? (01 Marks)

Q.2
(a) What do you understand by the term Addressing mode ? discuss the Addressing
modes supported by 8085 by giving suitable examples.(07 Marks)
(b) Design a memory system that contains 2K byte of of EPROM , immediately
followed by 1K byte of RWM. The EPROM begins at address 0000H and it is
implemented by using 1K byte of EPROM .The RWM is implemented using 1K
byte RAM chips . Use decoder and gates ( if needed ) for the interfacing
circuit.(07 Marks)
OR
(b) In instruction requires three machine cycles and 10 T states for the execution.
discuss using timing diagram, sequence of events taking place in every
machine cycle with reference
3000H …..IN 05H instruction.(07 Marks)
Q.3
(a) A set of ten BCD numbers are stored in memory locations starting from
2500H . Write an ALP to convert every BCD number to binary hex number and
store the outcome in memory locations starting from address 4000H (07 Marks)
(b) Design a modulo-12 down counter to count from 0BH to 00H . After count 00H
, the count should go back to 0BH and repeat the sequence. give one Sec. delay
ranging from count and display the count at an output port 01H. The clock freq. is 1
Mhz. Show your timing computations assuming suitable value of T states for
different instructions. Draw also the flow chart.(07 Marks)
OR
Q.3
(a) An array of binary numbers are stored in memory starting from address
3000H. There are ten numbers in the array. Write an ALP which obtains out
volume of positive numbers , negative numbers and zeros in the data array and
stores the outcome in memory location starting from address 3050H.(07 Marks)
(b) Write an ALP to multiply the contents of memory location 3040H by the
contents of memory location 3041H and store the outcome in memory
locations 3042H and 3043H with LS byte of the product at memory
location 3042H. Draw also the flow chart.(07 Marks)

Q.4
(a) discuss Memory Mapped I/O and Peripheral I/O and make the comparison ranging from them.(07 Marks)
(b) discuss the function of RIM and SIM instructions. (07 Marks)
OR
Q.4
(a) Write a detailed note on Memory Classification. (07 Marks)
(b) discuss clearly the interrupt arrangement in 8085 microprocessor with
improper diagram. How the interrupts are activated ? To which memory
location an interrupt points ? How the priority is organizes ? How the
interrupts can be cleared ?(07 Marks)

Q.5
(a) With the help of simplified block diagram discuss the internal architecture of
8255. How different parts can be addressed ?(07 Marks)
(b) List the major components of the 8279 keyboard / display interface, and
discuss their functions.(07 Marks)
OR
Q.5
(a) Write a note on the 8251A programmable communication interface. (07 Marks)
(b) List the major components of the 8259A interrupt controller , and discuss
their functions.(07 Marks)
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Earning:   Approval pending.