Q. 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
πŸ’¬ Discuss
βœ… Correct Answer: (B) D7=0

Q. 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
πŸ’¬ Discuss
βœ… Correct Answer: (B) IBF

Q. 8255 has three ----parrallel port

  • (A) 8bit
  • (B) 16bit
  • (C) 32bit
  • (D) 64bit
πŸ’¬ Discuss
βœ… Correct Answer: (A) 8bit

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

  • (A) mode 0
  • (B) mode1
  • (C) mode2
  • (D) BSR
πŸ’¬ Discuss
βœ… Correct Answer: (C) mode2

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

  • (A) Simplex
  • (B) Half duplex
  • (C) Full Duplex
  • (D) none of these
πŸ’¬ Discuss
βœ… Correct Answer: (B) Half duplex

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

  • (A) Simplex
  • (B) Half duplex
  • (C) Full Duplex
  • (D) none of these
πŸ’¬ Discuss
βœ… Correct Answer: (C) Full Duplex

Q. Asynchronous serial communication involves

  • (A) start bit
  • (B) stop bits
  • (C) character data
  • (D) all of these
πŸ’¬ Discuss
βœ… Correct Answer: (D) all of these

Q. 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
πŸ’¬ Discuss
βœ… Correct Answer: (B) mov al,0AEH

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

  • (A) TXRDY
  • (B) TXE
  • (C) TXC#
  • (D) both B and C
πŸ’¬ Discuss
βœ… Correct Answer: (B) TXE

Q. Adc 0808 uses ----technique

  • (A) Successive apraximation
  • (B) single step
  • (C) dual slope
  • (D) flash converter
πŸ’¬ Discuss
βœ… Correct Answer: (A) Successive apraximation

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