Guru Gobind Singh Indraprastha Vishwavidyalaya 2005 B.Tech Microprocessor System I - exam paper

Fifth Semester [B.Tech] - November 2005

Paper Code : ETEC – 303 Subject : Microprocessor System I

Time : 11/2 Hours
Maximum Marks : 30

Note : Attempt any three ques. in all. Make suitable assumptions where nessecary.


Q1 ( a ) The memory space of an 8085A based system consists of 1 8Kx8 bit EPROM starting from memory locations 0000H to 1FFFH and eight RAM chips every of 1Kx4 bits from the location 2000H. Draw the decoding circuit and draw the connection diagram.

( b ) explain the different mapping techniques used to establish the relationship ranging from the main memory and cache memory blocks. four
( c ) Consider the memory system with main memory size = 8K blocks; cache memory size = 512 blocks; block size = eight words. Determine the size of the tag field of the main memory address under the subsequent conditions:
Fully associative mapping
Direct mapping
Set associative memory with 16 blocks per set.

Q2 ( a ) explain the modes in which the Programmable Peripheral Interface device 8255A can be operated.

( b ) Determine the 8255 control word to be used when programming the port A as mode1 input port and port B as mode1 output port. INTEA and INTEB should both be enabled and the 2 unused port C lines should be described as outputs. Address of the control port is 83H. Draw the Connection diagram and write the initialization routine needed.

(c) Specify the handshake signals for port B of the 8155 if port B is connected as an input port in interrupt mode. discuss the functioning of every handshake signal. four


Q3 ( a ) Draw the connection diagram to show how the DMA controller 8237 can be interfaced with the 8-bit microprocessor 8085A and list the steps needed to accomplish data transfer with the peripheral. 5

( b ) Draw the block diagram of the Programmable Keyboard/Display Interface 8278 and discuss its operation. explain the format of the keyboard/display mode set command. five


Q4 Write short notes on :

( a ) Cache Controller 3

( b ) DRAM Controller 4

( c ) Programmable Interval Timer, 8254

Earning:   Approval pending.