SRM University 2007 B.Tech Information Technology IT201 MICROPROCESSOR AND ITS APPLICATIONS - Question Paper

suitable maps.
3. Explain the dynamic RAM refreshing logic with neat diagram.
4. Explain the control word format of 8255 in I/O & BSR mode? (5).
5. Explain the various modes of operation of 8255.
6. Interface an input port 74LS245 to learn the status of switches sw1 to sw8. The switches, when shorted, input a ‘1’ else input a ‘0’ to the 8086 system. Store the status in register BL. The address of port A is 0740H. (10)
7. Draw an internal architecture of 8255 and explain? (10).
8. Using 74LS373 output port and seven segment displays design a seconds counter that counts from 0 to 9. Draw the suitable hardware schematic and write an ALP for this issue. presume that a delay of one sec is available as a subroutine. choose the port address suitably. (10).
9. Interface an 8255 with 8086 so as to have port A address 00, port B address 02, port C address 01 and CWR address 03. (10)
10. Interface an 8255 with 8086 to work as I/O port. Initialize port A as output port, port B as input port and port C as output port. Port A address should be 0750H. Write a program to sense switch positions sw0-sw7 connected at port B. The sensed trend is to be displayed on port A, to which eight LEDs are connected, while port C lower displays number of on switches out of the total eight switches. (10)
11. Draw a schematic hardware circuit for interfacing five, seven seg displays with 8086 using output ports. Display numbers one to five on them continuously. The seven seg codes are stored in a look up table serially at the address 2000 : 000H onwards starting from code 1.
12. Draw and explain the analog to digital convertor 0808/0809.
13. Interface ADC 0808 with 8086 using 8255 ports. Use port A of 8255 for transferring digital data output of ADC to the CPU and porte for control signals. presume that an analog input is current at I/P2 of the ADC and a clock i/p of suitable frequency is available for ADC. Draw the schematic and write the needed ALP.
UNIT –III
PART A 2 Marks
1. Explain the significances of various bits of the control word register format of 8253
2. Explain the functions of the subsequent pins of 8259A
a. CAS0¬ – CAS2 b.
3. Explain the subsequent terms in relation to 8259A.
i. EOI ii. Automatic rotation iii. Automatic EOI iv. Specific rotation
v. Special mask mode vi. Edge and level triggered mode
vii. Cascading viii. Special fully nested mode ix. Buffered mode x. Polling

Earning:   Approval pending.