Serial Port Communication 1. What actually are the DB9, DB25 ports available in our computers? a) they are connectors used to transfer data either serially or parallelly b) they are the RS232 connectors used to connect two incompatible devices c) they are the TTL logic connector pins used for communication d) they are just data transfer pins used to transfer the data Answer: they are the RS232 connectors used to connect two incompatible devices 2. What does RI handshaking signal refer to according to the RS232 logic? a) if this logic is high then a receive interrupt is generated b) this pin is high during transmission c) this pin is high during a reception in order to tell that the device is busy at this particular time d) none of the mentioned Answer: this pin is high during a reception in order to tell that the device is busy at this particular time 3. What is the major difference between a MAX232 and a MAX233 device? a) one has one serial port other has two b) one has inbuilt UART

  AVR Microcontroller I/O Port Programming and Addressing Modes 1. In AVR, which registers are there for the I/O programming of ports? a) PORT b) PIN c) DDR d) All of the mentioned Answer: All of the mentioned 2. The data will not go from the port registers to the pin unless: a) DDR register of that port is set to 0 b) PORT register of that port is set to 1 c) DDR register of that port is set to 1 d) PORT register of that port is set to 0 Answer: DDR register of that port is set to 1 3. On reset DDR registers of all ports are set to: a) 0 b) 1 c) None of the mentioned d) 0 & 1 Answer: 0 4. Which of the following statements are correct? a) PIN register of a port is used to bring data into CPU from pins b) PORT register is used to send data out to pins c) DDR register is used to control the direction of a port d) All of the mentioned Answer: All of the mentioned 5. In the AVR family, all I/O ports have 8 pins? a) true b) false c) none of the mentioned d) can’t be determined Answer: f

  AVR Microcontroller Architecture 1. Is the following instruction correct LDI R3,50? a) Yes b) No c) Cant be said d) None of the mentioned Answer: No 2. Registers R0-R31 are used for what type of works? a) they are used for arithmetic and logic instructions b) they are used for data copy c) they are used for calculations d) none of the mentioned Answer: they are used for arithmetic and logic instructions 3. The largest value that can be loaded in an 8 bit register is? a) 11111111H b) FH c) FFH d) 00H Answer: FFH 4. The total space for the data memory available in the AVR based microcontroller is? a) FFH b) FFFH c) FFFFH d) FFFFFH Answer: FFFFH 5. Which of the following instructions affect the flags of the status register? a) AND b) INC c) OR d) All of the mentioned Answer: All of the mentioned 6. What is the difference between the two given instructions? LDI R16,0x34 and LDI R16,$34 a) One copies the hexadecimal value to R16 and the other copies the decimal value to the R16 register b