McqMate
1. |
for i/o of 8255,if -----, the word is taken as a bit set/rest word |
A. | D7=1 |
B. | D7=0 |
C. | D0=1 |
D. | D0=0 |
Answer» B. D7=0 |
2. |
on activation of ----, 8255 loads data from the input port lines into the input buffer of that port |
A. | STB# |
B. | IBF |
C. | OBF# |
D. | none of these |
Answer» B. IBF |
3. |
8255 has three ----parrallel port |
A. | 8bit |
B. | 16bit |
C. | 32bit |
D. | 64bit |
Answer» A. 8bit |
4. |
in ----, bidirectional data transfer is possible |
A. | mode 0 |
B. | mode1 |
C. | mode2 |
D. | BSR |
Answer» C. mode2 |
5. |
walkie-talkie is an example of …..serial communication |
A. | Simplex |
B. | Half duplex |
C. | Full Duplex |
D. | none of these |
Answer» B. Half duplex |
6. |
Transmission through telephone lines is an example of….serial commuincation |
A. | Simplex |
B. | Half duplex |
C. | Full Duplex |
D. | none of these |
Answer» C. Full Duplex |
7. |
Asynchronous serial communication involves |
A. | start bit |
B. | stop bits |
C. | character data |
D. | all of these |
Answer» D. all of these |
8. |
to configure 8255 with port A output,Port B input port C lower output and port C upper input |
A. | Mov al,0AFH |
B. | mov al,0AEH |
C. | mov Al,0CEH |
D. | Mov A,0AAH |
Answer» B. mov al,0AEH |
9. |
A high on ---line indicates that the buffer register is empty |
A. | TXRDY |
B. | TXE |
C. | TXC# |
D. | both B and C |
Answer» B. TXE |
10. |
Adc 0808 uses ----technique |
A. | Successive apraximation |
B. | single step |
C. | dual slope |
D. | flash converter |
Answer» A. Successive apraximation |
11. |
the signals provided by ADC are |
A. | SOC |
B. | EOC |
C. | ALE |
D. | all of these |
Answer» D. all of these |
12. |
Flash ADC consist of….converters |
A. | 2^n |
B. | 2^n -1 |
C. | 2^n +1 |
D. | none of these |
Answer» B. 2^n -1 |
13. |
8253/54 has ----independent timers/counters |
A. | 1 |
B. | 2 |
C. | 3 |
D. | 4 |
Answer» C. 3 |
14. |
8253/54 timers can be programmed in---modes |
A. | 1 |
B. | 3 |
C. | 6 |
D. | 5 |
Answer» C. 6 |
15. |
in mode 0 of 8253/54 ----disables counting |
A. | gate=1 |
B. | gate=0 |
C. | wr#=1 |
D. | wr#=0 |
Answer» 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 |
A. | write back |
B. | write ahead |
C. | read ahead |
D. | read back |
Answer» D. read back |
17. |
for mode 3 of 8253/54, if the count is odd the output will be high for--- |
A. | 2/(n+1) |
B. | (n+1)/2 |
C. | 2/(n-1) |
D. | (n-1)/2 |
Answer» B. (n+1)/2 |
18. |
EOC means |
A. | End of Conversion |
B. | Enable output conversion |
C. | error of conversion |
D. | none of these |
Answer» A. End of Conversion |
19. |
ADC 0808 is ----- pin IC |
A. | 40 |
B. | 20 |
C. | 24 |
D. | 28 |
Answer» D. 28 |
20. |
ADC 0808 operates on single ---- power supply |
A. | 5V |
B. | 10V |
C. | 15V |
D. | 20V |
Answer» A. 5V |
21. |
8255 has -------- i/o pins |
A. | 28 |
B. | 26 |
C. | 24 |
D. | 22 |
Answer» C. 24 |
22. |
8255 has three ----parallel ports |
A. | 8 bit |
B. | 16 bit |
C. | 32 bit |
D. | 64 bit |
Answer» A. 8 bit |
23. |
In 8255 ,BSR means ----- |
A. | bit set/reset |
B. | byteset/reset |
C. | binary set/reset |
D. | none |
Answer» A. bit set/reset |
24. |
BSR mode is used to set or reset the bitsin |
A. | portA |
B. | portB |
C. | portC |
D. | portD |
Answer» C. portC |
25. |
8255 has ----i/o modes |
A. | 2 |
B. | 3 |
C. | 4 |
D. | 8 |
Answer» B. 3 |
26. |
A high on ----pin causes all 24 lines of three 8 bit ports to be in the input mode |
A. | WR\ |
B. | RESET |
C. | GND |
D. | Vcc |
Answer» B. RESET |
27. |
For i/o mode of 8255,if -----,the word is taken as a mode definition word |
A. | D7=1 |
B. | D7=0 |
C. | D0=1 |
D. | D0=0 |
Answer» A. D7=1 |
28. |
For i/o mode of 8255 ,if -----, the word is taken as a bit set/reset word |
A. | D7=1 |
B. | D7=0 |
C. | D0=1 |
D. | D0=0 |
Answer» B. D7=0 |
29. |
On activation of --------,8255 loads data from the input port lines into the input buffer of that port |
A. | STB\ |
B. | IBF |
C. | OBF\ |
D. | NONE |
Answer» B. IBF |
30. |
IBF is an active-------- output signal for 8255 |
A. | high |
B. | low |
C. | enable |
D. | disable |
Answer» A. high |
31. |
8255 sets INTR when STB'=-----,IBF=---------,INTE=--------,for input conrol signals |
A. | 1,0,1 |
B. | 1,1,0 |
C. | 1,1,1 |
D. | 0,1,1 |
Answer» C. 1,1,1 |
32. |
Upon activation of------ signal,output device reads data from output port and acknowledges it |
A. | INTR |
B. | ACK\ |
C. | OBF\ |
D. | IBF |
Answer» C. OBF\ |
33. |
In ------ of 8255 ,bidirectionali/o data transfer is possible |
A. | mode0 |
B. | mode1 |
C. | mode2 |
D. | BSR MODE |
Answer» C. mode2 |
34. |
Walkie-talkie is an example of serial communication |
A. | simplex |
B. | half-duplex |
C. | full-duplex |
D. | none |
Answer» B. half-duplex |
35. |
Asynchronous serial communication involves transmission of |
A. | start bit |
B. | stop bit |
C. | character data |
D. | all |
Answer» D. all |
36. |
Whichof the following is the fastest ADC |
A. | DUAL SLOPE |
B. | successive approximation |
C. | flash |
D. | single slope |
Answer» C. flash |
37. |
To indicate end of conversion ADC 0808/0809 ACTIVATES -----SIGNAL |
A. | EOC |
B. | SOC |
C. | CLK |
D. | OUTPUT CONTROL |
Answer» A. EOC |
38. |
Conversion time Tc of successive approximation ADC is given as |
A. | T(n-1) |
B. | T(n+1) |
C. | T(n) |
D. | T(n+2) |
Answer» B. T(n+1) |
39. |
Conversion time of ADC 0808 IS |
A. | 100 ms |
B. | 100micro sec |
C. | 100 Ms |
D. | 100ns |
Answer» B. 100micro sec |
40. |
ADC 0809 IS A ----- PIN IC |
A. | 40 |
B. | 20 |
C. | 24 |
D. | 28 |
Answer» D. 28 |
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