Quiznetik

Microprocessors | Set 1

1. for i/o of 8255,if -----, the word is taken as a bit set/rest word

Correct : B. D7=0

2. on activation of ----, 8255 loads data from the input port lines into the input buffer of that port

Correct : B. IBF

3. 8255 has three ----parrallel port

Correct : A. 8bit

4. in ----, bidirectional data transfer is possible

Correct : C. mode2

5. walkie-talkie is an example of …..serial communication

Correct : B. Half duplex

6. Transmission through telephone lines is an example of….serial commuincation

Correct : C. Full Duplex

7. Asynchronous serial communication involves

Correct : D. all of these

8. to configure 8255 with port A output,Port B input port C lower output and port C upper input

Correct : B. mov al,0AEH

9. A high on ---line indicates that the buffer register is empty

Correct : B. TXE

10. Adc 0808 uses ----technique

Correct : A. Successive apraximation

11. the signals provided by ADC are

Correct : D. all of these

12. Flash ADC consist of….converters

Correct : B. 2^n -1

13. 8253/54 has ----independent timers/counters

Correct : C. 3

14. 8253/54 timers can be programmed in---modes

Correct : C. 6

15. in mode 0 of 8253/54 ----disables counting

Correct : B. gate=0

16. 8253/54 has c----command that allows the user to check the count value programmed mode and current status of the counter

Correct : D. read back

17. for mode 3 of 8253/54, if the count is odd the output will be high for---

Correct : B. (n+1)/2

18. EOC means

Correct : A. End of Conversion

19. ADC 0808 is ----- pin IC

Correct : D. 28

20. ADC 0808 operates on single ---- power supply

Correct : A. 5V

21. 8255 has -------- i/o pins

Correct : C. 24

22. 8255 has three ----parallel ports

Correct : A. 8 bit

23. In 8255 ,BSR means -----

Correct : A. bit set/reset

24. BSR mode is used to set or reset the bitsin

Correct : C. portC

25. 8255 has ----i/o modes

Correct : B. 3

26. A high on ----pin causes all 24 lines of three 8 bit ports to be in the input mode

Correct : B. RESET

27. For i/o mode of 8255,if -----,the word is taken as a mode definition word

Correct : A. D7=1

28. For i/o mode of 8255 ,if -----, the word is taken as a bit set/reset word

Correct : B. D7=0

29. On activation of --------,8255 loads data from the input port lines into the input buffer of that port

Correct : B. IBF

30. IBF is an active-------- output signal for 8255

Correct : A. high

31. 8255 sets INTR when STB'=-----,IBF=---------,INTE=--------,for input conrol signals

Correct : C. 1,1,1

32. Upon activation of------ signal,output device reads data from output port and acknowledges it

Correct : C. OBF\

33. In ------ of 8255 ,bidirectionali/o data transfer is possible

Correct : C. mode2

34. Walkie-talkie is an example of serial communication

Correct : B. half-duplex

35. Asynchronous serial communication involves transmission of

Correct : D. all

36. Whichof the following is the fastest ADC

Correct : C. flash

37. To indicate end of conversion ADC 0808/0809 ACTIVATES -----SIGNAL

Correct : A. EOC

38. Conversion time Tc of successive approximation ADC is given as

Correct : B. T(n+1)

39. Conversion time of ADC 0808 IS

Correct : B. 100micro sec

40. ADC 0809 IS A ----- PIN IC

Correct : D. 28