MTL200 EXAM QUESTIONS WITH 100%
CORRECT ANSWERS LATEST VERSION
2025/2026.
N/A -
What is the difference between volatile and non volatile memory in microcontrollers? -
ANS Volatile memory (RAM) loses stored data when power is removed. Non-volatile memory
(Flash, EEPROM) retains data even when power is lost.
How does a microcontroller execute instructions stored in its memory? - ANS It follows the
Fetch-Decode-Execute cycle: Fetch retrieves the instruction, Decode interprets it, and Execute
performs the operation.
Explain the role of the Control Unit (CU) in a microcontroller? - ANS The CU directs
instruction execution, manages communication between ALU, registers, and memory, and
controls data flow.
What is the purpose of the Status Register in a microcontroller? - ANS It stores flags that
indicate operation results, such as carry, zero, and overflow, which are used for conditional
execution.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, How many clock cycles does it take for an instruction to execute on an ATmega328P? -
ANS Most AVR instructions execute in 1 clock cycle, except for branching/jump instructions,
which take 2-3 cycles.
Name and explain three types of memory used in the ATmega328P microcontroller? -
ANS Flash (stores program code), SRAM (stores variables during execution), and EEPROM
(stores data that must be retained after power loss).
What is the function of the Stack Pointer (SP), and how does it change when pushing and
popping data? - ANS The SP holds the top address of the stack. Pushing data decrements SP,
while popping data increments SP.
What is the difference between general purpose registers and special function registers? -
ANS General purpose registers (R0-R31) store temporary data and arithmetic results, while
special function registers (e.g., SREG, SP) control system functions.
What is the function of the PINx register in ATmega328P? - ANS It reads the current logic
level of an input pin.
How do you configure Port D, Pin 5 as an output and set it to HIGH in C? - ANS Use DDRD |=
(1 << PD5); to set PD5 as an output and PORTD |= (1 << PD5); to set it HIGH.
What is the difference between PORTx, PINx, and DDRx registers? - ANS DDRx configures pin
direction, PORTx writes HIGH/LOW or enables pull-ups, and PINx reads input pin states.
Write an Assembly instruction to toggle a specific pin (e.g., PB3) without affecting other bits? -
ANS IN R16, PORTB; EOR R16, (1 << PB3); OUT PORTB, R16;
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
CORRECT ANSWERS LATEST VERSION
2025/2026.
N/A -
What is the difference between volatile and non volatile memory in microcontrollers? -
ANS Volatile memory (RAM) loses stored data when power is removed. Non-volatile memory
(Flash, EEPROM) retains data even when power is lost.
How does a microcontroller execute instructions stored in its memory? - ANS It follows the
Fetch-Decode-Execute cycle: Fetch retrieves the instruction, Decode interprets it, and Execute
performs the operation.
Explain the role of the Control Unit (CU) in a microcontroller? - ANS The CU directs
instruction execution, manages communication between ALU, registers, and memory, and
controls data flow.
What is the purpose of the Status Register in a microcontroller? - ANS It stores flags that
indicate operation results, such as carry, zero, and overflow, which are used for conditional
execution.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, How many clock cycles does it take for an instruction to execute on an ATmega328P? -
ANS Most AVR instructions execute in 1 clock cycle, except for branching/jump instructions,
which take 2-3 cycles.
Name and explain three types of memory used in the ATmega328P microcontroller? -
ANS Flash (stores program code), SRAM (stores variables during execution), and EEPROM
(stores data that must be retained after power loss).
What is the function of the Stack Pointer (SP), and how does it change when pushing and
popping data? - ANS The SP holds the top address of the stack. Pushing data decrements SP,
while popping data increments SP.
What is the difference between general purpose registers and special function registers? -
ANS General purpose registers (R0-R31) store temporary data and arithmetic results, while
special function registers (e.g., SREG, SP) control system functions.
What is the function of the PINx register in ATmega328P? - ANS It reads the current logic
level of an input pin.
How do you configure Port D, Pin 5 as an output and set it to HIGH in C? - ANS Use DDRD |=
(1 << PD5); to set PD5 as an output and PORTD |= (1 << PD5); to set it HIGH.
What is the difference between PORTx, PINx, and DDRx registers? - ANS DDRx configures pin
direction, PORTx writes HIGH/LOW or enables pull-ups, and PINx reads input pin states.
Write an Assembly instruction to toggle a specific pin (e.g., PB3) without affecting other bits? -
ANS IN R16, PORTB; EOR R16, (1 << PB3); OUT PORTB, R16;
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
