Guru Gobind Singh Indraprastha Vishwavidyalaya 2005 B.Tech Microprocessor System I - Question Paper

Fifth Semester [B.Tech] - September 2005

Paper Code : ETEC – 303 Subject : Microprocessor System I

Time : 11/2 Hours
Maximum Marks : 30

Note : Attempt any three ques. in all. every ques. carries 10 marks. Make suitable assumptions wherever necessary.


Q1 ( a ) Draw the logic diagram of a circuit the generates the control strobes
MEMR, MEMW, I/OR AND I/OW

( b ) discuss the functions of the subsequent pins in the 8-bit microprocessor 8085A.
i ) READY ii ) HOLD iii) RESETIN three
( c ) discuss the methods of driving the clock input circuits X1 and X2. four

Q2 ( a ) List the machine cycle involved in the subsequent instructions in the order of their occurrence.

LHLD addr
MOV R, M
DAD Rp
CALL addr

( b ) explain the addressing modes available in the 8-bit microprocessor 8085A.
( c ) Write a program for the 8-bit microprocessor 8085A, to multiply 2 8-bit numbers stored in memory locations with addresses N1 and N2 respectively. The product is to be placed in memory locations with addresses N3 and N4, lower byte of the product being at address N3. Use assembly language mnemonics.


Q3 ( a ) Write a delay subroutine for the 8085A to generate a delay of 100ms. presume the crystal frequency to be 6.250 MHz.

( b ) State the conditions to be satisfied for the interrupt request on the input pin, INTR, to be recognized as a valid interrupt for service.


Q4 Write short notes on :

( a ) Programmable Interrupt Controller, 8259A 4

( b ) Halt and Hold states in 8085A 3

( c ) SIM and RIM instructions 3

Earning:   Approval pending.