Embedded System Questions and Answers Part-30

1. Which of the following are the three hardware signals?
a) START, STOP, ACKNOWLEDGE
b) STOP, TERMINATE, END
c) START, SCL, SDA
d) STOP, SCL, SDA

Answer: a
Explanation: The three hardware signals are START, STOP and ACKNOWLEDGE. These signals help in the transmission of data between the slave and the masters

2. Which of the following performs the START signal?
a) master
b) slave
c) CPU
d) memory

Answer: a
Explanation: The START signal is performed by the master by making the SCL and SDA pin high.

3. Which of the following are handshake signals?
a) START
b) STOP
c) ACKNOWLEDGE
d) START and STOP

Answer: c
Explanation: The START signal and ACKNOWLEDGE signals are almost similar but there exhibits a small change. The START signal is initiated by the master only but the ACKNOWLEDGE signal is a handshake between both the master and slave.

4. A packet is also referred to as
a) postcard
b) telegram
c) letter
d) data

Answer: b
Explanation: The data is transmitted in packets with a having one or more bytes. These packets of data are also known as a telegram.

5. Which of the following byte performs the slave selection?
a) first byte
b) second byte
c) terminal byte
d) eighth byte

Answer: a
Explanation: The slave selection is performed by using the first byte as an address byte. When the address byte is sent out all the slave devices compares the address by its own value. If there is a match, the ACKNOWLEDGE signal will be sent by the slave.

6. Which of the following indicates the type of operation that the master requests?
a) address value
b) initial value
c) terminal count
d) first byte

Answer: a
Explanation: The address value helps the master to select the device and indicates what operation should be taken. If the 8th bit is logic one, read operation takes out and if it is logic zero, write operation takes out.

7. Which counter selects the next register in the I2C?
a) auto-incrementing counter
b) decrementing counter
c) auto-decrementing counter
d) terminal counter

Answer: a
Explanation: The peripheral having a small number of locations can use auto-incrementing counter for accessing the next register. But this will not be applicable in bigger memory devices

8. Which is an efficient method for the EEPROM?
a) combined format
b) auto-incrementing counter
c) register set
d) single format

Answer: a
Explanation: Combined format is an efficient method for the EEPROM because it is having a large number of registers.

9. Which can determine the timeout value?
a) polling
b) timer
c) combined format
d) watchdog timer

Answer: a
Explanation: The polling can be used along with the counter to determine the timeout value.

10. Which of the following can determine if two masters start to use the bus at the same time?
a) counter detect
b) collision detect
c) combined format
d) auto-incremental counter

Answer: b
Explanation: The collision detects technique helps to determine whether two or more masters are using the same bus in a multi-master device.