31. Which of the following depends on the number of bits that are transferred?
A. wait for the statement
B. ready statement
C. time
D. counter
Answer: C
The time taken for the data transmission within the system depends on the clock frequency and the number of bits that are transferred.
32. Which of the following is the most commonly used buffer in serial porting?
A. LIFO
B. FIFO
C. FILO
D. LILO
Answer: B
Most of the serial ports use a FIFO buffer so that the data is not lost. The FIFO buffer is read to receive the data, that is, first in first out.
33. What does SPI stand for?
A. serial-parallel interface
B. serial peripheral interface
C. sequential peripheral interface
D. sequential port interface
Answer: B
The serial-parallel interface bus is a commonly used interface that involves a master-slave mechanism. The shift registers are worked by the master and the slave devices are driven by a common clock.
34. Which allows the full-duplex synchronous communication between the master and the slave?
A. SPI
B. serial port
C. I2C
D. parallel port
Answer: A
The serial peripheral interface allows the full-duplex synchronous communication between the master and the slave devices. MC68HC05 developed by Motorola uses SPI for interfacing peripheral devices.
35. Which of the following processor uses SPI for interfacing?
A. 8086
B. 8253
C. 8254
D. MC68HC11
Answer: D
The MC68HC05 and MC68HC11 microcontrollers use the serial peripheral interface for the peripheral interfacing.
36. In which register does the data written in the master device?
A. index register
B. accumulator
C. SPDR
D. status register
Answer: C
The serial peripheral interface follows a master-slave mechanism in which the data is written to the SPDR register in the master device and clocked out into the slave device SPDR by using a common clock signal called SCK.
37. What happens when 8 bits are transferred in the SPI?
A. wait statement
B. ready statement
C. interrupt
D. remains unchanged
Answer: C
The interrupts are locally generated when 8-bits are transferred so that the data can be read before the next byte is clocked through.
38. Which signal is used to select the slave in the serial peripheral interfacing?
A. slave select
B. master select
C. interrupt
D. clock signal
Answer: A
The slave select signal selects which slave is to receive data from the master.
Chip select (CS) or slave select (SS) is the name of a control line in digital electronics used to select one (or a set) of integrated circuits (commonly called “chips”) out of several connected to the same computer bus, usually utilizing the three-state logic.
39. How much time period is necessary for the slave to receive the interrupt and transfer the data?
A. 4 clock time period
B. 8 clock time period
C. 16 clock time period
D. 24 clock time period
Answer: B
The SPI uses an eight-clock time period for the slave to receive the interrupt and transfer the data which determines the maximum data rate.
40. What does I2C stand for?
A. inter-IC
B. intra-IC
C. individual integrated chip
D. intel IC
Answer: A
The I2C is known as inter-IC, which is developed by Philips for interfacing with peripheral devices.
41. Which company developed I2C?
A. Intel
B. Motorola
C. Phillips
D. IBM
Answer: C
The I2C is developed by Philips for use in television sets.
42. Which of the following is the most known simple interface?
A. I2C
B. Serial port
C. Parallel port
D. SPI
Answer: A
The I2C is the most known simple interface which is used currently. It can combine both the hardware and the software protocols to provide a bus interface that helps in the communication with many peripherals.
43. Which are the two lines used in the I2C?
A. SDA and SPDR
B. SPDR and SCL
C. SDA and SCL
D. SCL and status line
Answer: C
The I2C bus consists of two lines which are called SDA and SCL. The master and slave devices are attached to these lines.
44. Which of the following developed P82B715?
A. Philips
B. Intel
C. IBM
D. Motorola
Answer: A
The special buffer chip, P82B715 for increasing the current drive is developed by Philips.
45. Which pin provides the reference clock for the transfer of data?
A. SDA
B. SCL
C. SPDR
D. Interrupt pin
Answer: B
The SCL pin can provide the reference clock for the transmission of data but it is not a free-running clock.
