Interfacing Through Microprocessors March06 Nr310501

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Code No: NR310501

III B.Tech I Semester Supplementary Examinations, March 2006 INTERFACING THROUGH MICROPROCESSORS ( Common to Computer Science & Engineering, Information Technology and Computer Science & Systems Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) If an absolute address of the type 6A3D9H is given, express it in the form of CS : IP and explain what are the advantages of the memory segmentation. Discuss about the various segment registers in 8086. (b) What are the modes in which the 8086 can be used .How many lines are there in the multiplexed bus of 8086. Give the pin diagram separately for each mode of operation. [8+8] 2. Develop an 8086 assembly language program that converts the given hexadecimal data into ASCII and vice-versa. [16] 3. Use the 8086 string instructions to write a program which scans a string of 80 characters looking for a carriage return (0DH). If a carriage return is found, put the length of the string up to the carriage return in AL. If no carriage return is found, put 50H in AL. [16] 4. An 8086 system with 8255 interfaced at port A address F0H, as a block of 100 data bytes Stored in it. Another 8086 system with another 8255 interface at port A address 80H has another block of 100 data bytes stored in it. Interchange this blocks of data bytes between the two 8086 systems. Draw the necessary hardware scheme and write the necessary sequence of instructions. Both systems run on the same clock rate. [16] 5. (a) Write about interrupt sequence in an 8086 system (b) Explain about command words of 8259 (c) Show interfacing schematic for connecting 13 interrupting devices to 8086 using 8259 [4+6+6] 6. (a) Design a circuit to activate a actuator, based on a bit combination given by eight switches interfaced to a microprocessor (b) Design a interface circuit to feed numbers 0-9 through a linearly encoded switches and to display the number on a seven segment LED through a microprocessor [8+8] 7. What do you mean by dual ported memory? Explain how CRT controller exploits it to display data on screen [16] 8. (a) Describe the functions of the DSR, DTR, RTS, CTS, TXD, and RXD signals exchanged between a terminal and a modern. 1 of 2

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Code No: NR310501

(b) Why is synchronous serial data communication much more efficient than asynchronous communication? (c) List out various signals in 1 EEE 488 and their purpose and explain.[6+4+6] ?????

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