M.Sc. (Semester IV) (CBCS) Examination Nov/Dec-2018
Physics (Applied Electronics)
MICROPROCESSORS INTERFACING
Time: 2½ Hours Max. Marks: 70
Instructions: Q.1 and Q.2 is compulsory.
Any three questions from Q.3 to Q.7.
Figures to the right indicate full marks.
Q.1 Choose the correct option:- 08
If the programmable counter timer 8253 is set in mode 4 then it is
Square wave generator Rate pulse generator
Software triggered Hardware triggered
Which pins are general purpose I/O pins during mode-1 operation of
the 8255?
PA0 PA7 PB0-PB7
Both a b PC0-PC2
If A0 A1 pin of 8253 is connected to A0 and A1 address line and
remaining address line i.e. from A2 to A7 connected to VCC then the
address of control word register.
FFH FDH
FBH FEH
Tick the correct instruction
STAX H STA B
INX L LDAX B
20 bit address bus provides access to memory of capacity
64 KB 32 KB
1 MB 8 KB
Commonly used IC for converting Analog to Digital uses
Weighted resistor R-2R
Flash Successive approximation
The delay provided by the NOP instruction for 2MHz crystal frequency
1s 2s
3s 4s
When RST7.5 interrupt is triggered in an intel 8085A, the program
control is transferred to which one of the following?
0034H 003CH
002CH 0024H
Q.1 State True or False:- 06
RST 5.5 is edge trigged interrupt.
Maximum 64K of external memory we can interface to 8085.
In the Mode-2 of 8255 Port C is used for bidirectional input output.
ADC 0809 is a flash type of ADC.
In the PIC 8259 four ICWs (initialization Command Words) are exist.
To execute LXI 9000H instruction 13T states are required.
Q.2 Differentiate between I/O mapped I/O and Memory mapped I/O.
Explain the Flash type of ADC
Explain the control word format of 8255.
05
05
04
Q.3 Interface 8K x 8 RAM to 8085. Determine its initial and final address.
Explain the interrupt structure of 8085.
08
06
Q.4 Interface 8255 to 8085 in I/O mapped I/O. Determine the addresses of all
ports.
Explain the Mode-1 of 8255.
08
06
Q.5 Draw and explain the block diagram of 8279.
Explain the weighted resistor type DAC.
08
06
Q.6 Interface ADC0809 to 8085 through 8255. Explain the process of converting
analog input to digital in stepwise manner.
08
Explain the features of 8259. 06
Q.7 Explain the OCWs (Operational Command Words) of 8259. 08
Explain the Square Wave generation mode of 8253 with the help of
waveforms.