M.Sc. (Semester IV) (CBCS) Examination Mar/Apr-2018
Physics (Applied Electronics)
MICROPROCESSORS INTERFACING
Time: 2½ Hours
Max. Marks: 70
Instructions: Questions 1 and 2 are compulsory. Answer any three questions from Q.3 to Q.7. Figures to the right indicate full marks.
Q.1

Choose the correct option
08
The 8259 is
PPI device
PIC device
PIT device
Keyboard and display interface
Which pins are used as handshaking signals during mode-1 operation of the 8255?
PA0 PA7
PB0-PB7
PC0-PC5
PC6-PC7
The advantages of I/O mapped I/O over memory mapped I/O is,
Faster
Many instructions supporting I/O mapped I/O
Require a bigger address decoder
All the above
8253, a programmable interval timer consists of
Three, 8-bit counters
Two, 16-bit counters
Three, 16-bit counters
Two, 8-bit counters
In memory mapped scheme, the devices are viewed as
Distinct I/O devices
Memory locations
Only input devices
Only output devices
The time taken by the ADC from the active edge of SOC (start of conversion) pulse till the active edge of EOC (end of conversion) signal is called
Edge time
Conversion over
Conversion delay
Time delay
The operation that can be performed on control word register is
Read operation
Write operation
Read and write operations
None of these
The RST7.5 is
Level triggered interrupt
Non maskable interrupt
Highest priority interrupt
Edge triggered interrupt
State true or false
06
Software interrupts are vectored interrupts.
To interface 32K of memory to 8085, fifteen address lines are required.
The display can be blanked by using BD line of 8279.
ADC0809 is a 16 bit.
In the 8255 Mode-2 the Port-B either can be used in Mode-0 or Mode-1.
In the general purpose mode of 8259 IR7 as the highest priority.
Page 2 of 2
SLR-UR-577
Q.2
Write a program to generate a square wave on PC1 pin be using BSR mode.
05
Explain the control word format of 8253.
05
Explain the features of 8255.
04
Q.3
Interface 2K × 8 EPROM to 8085 by using 2K × 4 EPROM. Determine its initial and final address.
08
Draw the block diagram of 8255.
06
Q.4
Interface 8259 to 8085 in I/O mapped I/O. Use 3:8 decoder for address decoding.
08
Explain the Mode-1 of 8255
06
Q.5
Draw and explain the block diagram of 8253.
08
Explain the different modes of 8253.
06
Q.6
Interface 8279 to 8085. Use 3:8 decoder for address decoding
08
Explain the features of 8279.
06
Q.7
Explain the ICWs (Initialization Command Words) of 8259
08
Explain flash type of ADC.
06