Bhavnagar University 2007 B.Sc Computer Science MICRO PROCESSORS - Question Paper

MICRO PROCESSORS


Time: three hrs
Max Marks: 70

First ques. is Compulsory

ans any 4 from the remaining ques.

All ques. carry equal marks

ans all parts of any ques. at 1 place

1. a) provide important specifications of a semiconductor memory device.
b) How a bit stored in a FAMOS device can be erased?
c) Distinguish ranging from µP, interfacing and I/O interfacing
d) provide the status register details of peripheral IC - 8279
e) A 12-bit ADC is operating with one µSec. clock period and the total conversion time is seen to be 14 µSecs. Write the kind of this ADC with a brief justification.
f) elaborate the important features of 8051 ?
g) Distinguish ranging from BIOS Function call and DOS Function call.

2. a) provide the I/O diagram, Functional Block diagram, Function table, memory cell, and learn Timing diagram for 2K x eight SRAM discuss its working.

b) Design 16k x eight SRAM memory interface at 4000H Using 2k x eight SRAMS with 8085 based system with fully decoded addressing logic. provide memory address range for every SRAM

3. a) What do you understand by "Interfacing an I/O device to a µP.” ? provide the characteristics and functions of various kinds of interfaces with respect to a µP. system. Outline briefly the procedure for interfacing an I/O device to a µP-based system.

b) Compare and contrast different I/O programming methods.

4. The 8255 PPI is to be used to interface a single 7 segment LED display unit and an 8-bit DIP switch to an 8085-based system.

a) Draw a logic diagram showing all connections ranging from the LED, the DIP switch, the 8255. and the system bus. Show also any additional components needed, such as driver circuits.

b) Write an I/O program that reads the DIP switch and if bit i is switched on, reason the corresponding decimal digit i to be displayed by the LED display unit.

5. presume that 2 similar µP-based systems are to be linked for exchanging messages. Consider a message as a sequence of maximum 100 data bytes that must be transfeffed from main memory of 1 system to that of the other system. Message transfer is accomplished by every system treating the other as 1 of its I/O devices. Usiug either 8085 or 8086 to implement the host µPs., carry out the following:

a) Design a suitable hardware interface for intersystem commumcation based on programmable interface circuits such as the 8255 or 8251
b) Write the structure of software needed for message transfer, explaining clearly how the activities of the 2 µPs. are synchronized.

6. a) Write clearly the complete specifications of 8-bit DAC device and 8-bit ADC device

b) Write both hardware and software to implement 8-bit ADC using 8-bit DAC by interfacing 8-bit DAC to 8085-based system.

7. a) Write briefly 8051 architectural features. Write 8051 assembly language program to learn 4-bit binary number from an input port and display its 2’s complement value on a 7-segment LED display at an output port.

b) Briefly explain about hardware organization of IBM compatible PC. Write either assembly language program or high level language program to learn a character from keyboard and display on the screen of PC continuously using DOS function calls.

8. Write short notes on the following:
a) Programmable Logic Devices
b) 8253 Timer Architecture
c) Programming 8279
d) ROM BIOS

Earning:   Approval pending.