JNTU B.Tech II Semester Examinations, MICROPROCESSORS AND MICRO CONTROLLERS, Apr/May 2008
(Electrical & Electronic Engineering)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
1. (a) Discuss the minimum mode memory control signals of 8086?
(b) Explain the write cycle operation of the microprocessor with a neat timing
diagram in maximum mode. [8+8]
2. (a) Write short notes on Linker?
(b) Write an ALP to find the largest among a given array of 16 bit numbers?
(choose the length of the array as 100)
3. (a) Explain the steps involved in the Interfacing of an I/O device
(b) Explain various methods of interfacing of I/O devices. [6+10]
4. (a) Explain the bus structure of 8086 system
(b) Explain the differences between memory and I/O interfacing. [8+8]
5. (a) Write an 8086 instruction sequence for transmitting 50 characters which are
stored from the location 2010H using 8251.
(b) Write an 8086 instruction sequence for receiving 50 characters using 8251 and
store them in memory at location 2080H. [8+8]
6. Discuss the following signals of 8051
(a) INT0 / INT1
(e) T0 and T1
(h) RxD 
7. (a) Write 8051 program to generate 2 kHz square waves on pin P1.0 of port 1
using Timer interrupt.
(b) Write 8051 program to receive a serial byte through RxD. [8+8]
8. (a) Interface the 7-segment displays in time-multiplexing and display select method
and explain the same.
(b) Write a 8051 program to control the operation of a 7-segment displays with
time multiplexing and display method. Assume that the 7-segment codes for
the characters to be displayed are at 40,42,44,46H respectively in the internal RAM. Whereas, the cathode select codes for each of the displays are at
41,43,45,47H respectively. [8+8]