Microprocessors and Microcontrollers (3160914) MCQs

MCQs of Applications and design of microcontroller based systems

Showing 11 to 20 out of 40 Questions
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11.

Which of the following steps detects the key in a 4*4 keyboard matrix about the key that is being pressed?

(a)

masking of bits
(b)

ensuring that initially, all keys are open
(c)

checking that whether the key is actually pressed or not
(d)

all of the mentioned
Answer:

Option (d)

12.

What is described by this command: CJNE A,#00001111b, ROW1

(a)

it masks the bit and then jumps to the label where ROW1 is written
(b)

it makes the value of the accumulator 0FH and then jumps at the address where ROW1 label is written
(c)

it compares the value of the accumulator with 0FH and jumps to the location where ROW1 label is there if the value becomes equal
(d)

it compares the value of the accumulator with 0FH and jumps to the location where ROW1 label is there if the value is not equal
Answer:

Option (d)

13.

To detect that in which column, the key is placed?

(a)

we can mask the bits and then check it
(b)

we can rotate the bits and then check that particular bit which is set or reset(according to the particular condition)
(c)

none of the mentioned
(d)

all of the mentioned
Answer:

Option (d)

14.

In reading the columns of a matrix, if no key is pressed we should get all in binary notation

(a)

o
(b)

1
(c)

F
(d)

7
Answer:

Option (b)

15.

If we need to operate a key of a keyboard in an interrupt mode, then it will generate what kind of interrupt?

(a)

ES
(b)

EX0/EX1
(c)

T0/T1
(d)

RESET
Answer:

Option (b)

16.

To identify that which key is being pressed, we need to:

(a)

ground all the pins of the port at a time
(b)

ground pins of the port one at a time
(c)

connect all the pins of the port to the main supply at a time
(d)

none of the mentioned
Answer:

Option (b)

17.

Key press detection and Key identification are:

(a)

the same processes
(b)

two different works are done in Keyboard Interfacing
(c)

none of the mentioned
(d)

any of the mentioned
Answer:

Option (b)

18.

Why two pins for ground are available in ADC0804?

(a)

for controlling the ADCON0 and ADCON1 register of the controller
(b)

for controlling the analog and the digital pins of the controller
(c)

for both parts of the chip respectively
(d)

for isolate analog and digital signal
Answer:

Option (d)

19.

What is the function of the WR pin?

(a)

its active high input used to inform ADC0804 to the end of conversion
(b)

its active low input used to inform ADC0804 to the end of conversion
(c)

its active low input used to inform ADC0804 to the start of conversion
(d)

its active high input used to inform ADC0804 to the start of conversion
Answer:

Option (c)

20.

State which of the following statements are false?

(a)

CLK IN pin used for External Clock Input or Internal Clock with external RC element
(b)

INTR pin tells about the end of the conversion
(c)

ADC0804 IC is an 8 bit parallel ADC in the family of the ADC0800 series
(d)

None of the mentioned
Answer:

Option (d)

Showing 11 to 20 out of 40 Questions
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