Data represntation

Question 1

What architecture family does the ATmega328P belong to?

Answer 1

The AVR 8-bit RISC microcontroller family.

Question 2

What does RISC stand for?

Answer 2

Reduced Instruction Set Computer.

Question 3

How many general-purpose registers does the AVR architecture have?

Answer 3

32 registers (R0–R31).

Question 4

Why are AVR registers arranged in one register file?

Answer 4

To allow fast single-cycle arithmetic and logic operations.

Question 5

What are the three 16-bit pointer registers?

Answer 5

X, Y, and Z.

Question 6

What do pointer registers do?

Answer 6

Access data memory indirectly.

Question 7

What memory organisation does the ATmega328P use?

Answer 7

Harvard architecture.

Question 8

Where are program instructions stored?

Answer 8

Flash memory.

Question 9

What memory stores variables and the stack?

Answer 9

SRAM.

Question 10

What memory stores small non-volatile data?

Answer 10

EEPROM.

Question 11

What is the width of the program counter?

Answer 11

16 bits.

Question 12

What does the instruction decoder do?

Answer 12

Determines the CPU operations required for each instruction.

Question 13

What does the ALU do?

Answer 13

Performs arithmetic and logic operations.

Question 14

What does SREG contain?

Answer 14

Status flags (Carry, Zero, Negative, Overflow, Sign, Half-Carry, Bit-copy, Global Interrupt Enable).

Question 15

What does the Global Interrupt Enable (I) flag do?

Answer 15

Enables or disables all maskable interrupts.

Question 16

What does the Stack Pointer do?

Answer 16

Points to the top of the stack in SRAM.

Question 17

What is the stack used for?

Answer 17

Return addresses, saved registers, local variables.

Question 18

What are I/O registers?

Answer 18

Memory-mapped registers used to configure peripherals.

Question 19

How wide is the ATmega328P data bus?

Answer 19

8 bits.

Question 20

How wide is the program memory address bus?

Answer 20

16 bits.

Question 21

What is memory-mapped I/O?

Answer 21

Assigning peripheral registers to addresses in the data memory space.

Question 22

What are the three registers for each I/O port?

Answer 22

DDRx, PORTx, PINx.

Question 23

What does DDRx control?

Answer 23

Pin direction (input 0, output 1).

Question 24

What does PORTx do?

Answer 24

Outputs logic values or enables pull-ups.

Question 25

What does PINx read?

Answer 25

Logic levels on input pins.

Question 26

What converts analogue voltages to digital values?

Answer 26

ADC.

Question 27

What is the resolution of the ADC?

Answer 27

10-bit (0–1023).

Question 28

What are timers used for?

Answer 28

Delays, counting events, PWM, timing operations.

Question 29

Name the three timers.

Answer 29

Timer0 (8-bit), Timer1 (16-bit), Timer2 (8-bit).

Question 30

What interface is used for serial communication?

Answer 30

USART.

Question 31

What interface is used for synchronous serial communication?

Answer 31

SPI.

Question 32

What interface is used for two-wire serial communication?

Answer 32

I2C (TWI).

Question 33

What is a peripheral module?

Answer 33

A hardware block providing functions such as ADC, timers, serial interfaces.

Question 34

What is the purpose of the clock system?

Answer 34

Provides timing signals for instruction execution and peripherals.

Question 35

Name common clock sources.

Answer 35

Internal RC oscillator, external crystal, external clock input.

Question 36

What does the prescaler do?

Answer 36

Divides the clock frequency to lower speeds.

Question 37

Why use a lower clock?

Answer 37

To reduce power consumption.

Question 38

What are power-saving modes for?

Answer 38

Reducing energy use when the CPU or modules are idle.

Question 39

What module wakes the CPU from sleep?

Answer 39

Interrupt controller.

Question 40

What are interrupts used for?

Answer 40

Letting the CPU respond immediately to hardware events.