Rajasthan Technical University 2011-4th Sem B.Tech Information Technology ester-(main/back) e/y- - Question Paper

B.Tech (Semester 4th)(Main/Back)Examination,June/July-2011
C.S And I.T
4IT1 Microprocessor & Interface


1 (a) How a program is executed by microprocessor 8085 ?
discuss by using diagram of flow of signal for the execution of a stored instruction.

(b) discuss the requirement of a program counter, stock pointer and instruction register in the
architecture of Intel 8085 microprocessor.

OR
1 (a) Why a microprocessor needs ROM and RAM ?write the procedure to communicate with memory by
a microprocessor.
(b) discuss the function of flag register in MP8085.What is the use of general purpose registers w and z?

2 (a)Explain the subsequent instructions indicating their addressing modes , flag affected , number and names of machine cycles on the execution of every :XRA A,CALL,XHTL,LHLD.
(b)Write a program to count the no of 1's and 0 bit in a register . presume data is in B register and store number of one in H register and 0 in L register.

OR
2 (a)write a program to compare 2 strings of ASCII characters to see if they are identical . The length of the string is in memory location 90XXH.One string begins in memory location A0XXH and the other in memory location B0XXH.If the 2 strings match , clear the memory location B0XXH otherwise set memory location B0XXH to FFH.
(b)Explain with example how flags can be set or reset in 16-bit instructions.

3 (a)Draw the timing diagram for the instruction SHLD BABAH.
Show of the status of the different signals: A8-A15, AD7-Ado,ALE,¬RD,IO/¬M,So,S1,¬WR.
(b)what is the difference ranging from MACROS and subroutine.
discuss with example.
OR
3 (a) Draw and discuss the block diagram of 8259 PIC.
(b) Interface 2 chips of 4k byte RAM and 2 chips of 2K byte Rom to MP 8085 by absolute decoding using 74LS138 decoder . provide the memory map starting at address 8000H for EPROM.
4(a) Draw the functional block diagram of 8254 IC and discuss how this can be used to find a signal having frequency equal to 1/6 of input clock signal.
(b) Interface 2 LED's using common cathode and common anode technique . Show the complete interface.
Write the program to blink them alternatively.
presume part addresses in IO mapped IO.
OR
4(a) Draw the block diagram of 8255 PPI. elaborate various operating modes of 8255 PPI? explain how to determine the control word for 8255?
(b)Interface the keyboard and display controller 8279 with 8085 at address ABC0H.Write an ALP to set up 8279 in scanned keyboard mode with encoded scan, N-key roll-over mode . Use 16-charater display in right entry display format.
5(a) write a program to transmit 256 bytes of data from system A Asynchronous transmission is to be done using 8251 and RS 232 C cable .Draw a schematic diagram to show how RS 232C cable is connected through 8251 to 8085.
(b)Write short note on IEEE 488.
OR
5(a)Interface eight switches and a 7 segment display to 8085 through 8255 PPI. Write a program to display the switch when a switch is open. presume that the 8255 is interfaced in memory mapped IO technique.
(b) Specify mode word ,command word and status word to transmit data. The TXC is 152.6KHZ.The requirement of system is :
1.Asynchronous mode with 9600 band
2.Character length of five Bits
3.1 stop bit
4.Even parity check.

Earning:   Approval pending.