Microprocessor MCQ (Multiple Choice Questions) - SchoolingAxis

Microprocessor MCQ (Multiple Choice Questions)

 1. The pin that clears the control word register of 8255 when enabled is

a. CLEAR

b. SET

c. RESET

d. CLK


Ans- c. RESET


2. The function, 'data bus tristated' is performed when

a. CS(active low) = 1

b. CS(active low) = 0

c. CS(active low) = 0, RD(active low) = 1, WR(active low) = 1

d. CS(active low) = 1 OR CS(active low) = 0, RD(active low) = 1, WR(active low) = 1


Ans- d. CS(active low) = 1 OR CS(active low) = 0, RD(active low) = 1, WR(active low) = 1


3. If A1=0, A0=1 then the input read cycle is performed from

a. port A to data bus

b. port B to data bus

c. port C to data bus

d. CWR to data bus


Ans- b. port B to data bus


4. The port that is used for the generation of handshake lines in mode 1 or mode 2 is

a. port A

b. port B

c. port C Lower

d. port C Upper


Ans- d. port C Upper


5. The device that receives or transmits data upon the execution of input or output instructions by the microprocessor is

a. control word register

b. read/write control logic

c. 3-state bidirectional buffer

d. none of the mentioned


Ans- c. 3-state bidirectional buffer


6. The input provided by the microprocessor to the read/write control logic is

a. RESET

b. A1

c. WR(ACTIVE LOW)

d. All of the mentioned


Ans- d. All of the mentioned


7. The data bus buffer is controlled by

a. control word register

b. read/write control logic

c. data bus

d. none of the mentioned


Ans- b. read/write control logic


8. All the functions of the ports of 8255 are achieved by programming the bits of an internal register called

a. data bus control

b. read logic control

c. control word register

d. none of the mentioned


Ans- c. control word register


9. Port C of 8255 can function independently as

a. input port

b. output port

c. either input or output ports

d. both input and output ports


Ans- c. either input or output ports


10. Programmable peripheral input-output port is another name for

a. serial input-output port

b. parallel input-output port

c. serial input port

d. parallel output port


Ans- b. parallel input-output port

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