2103 Quiz

A digital illustration depicting a microcontroller circuit with interrupt flags and a keypad, showcasing electronics components and coding logic

Microcontroller Interrupts and Keypad Quiz

Test your knowledge on microcontroller interrupts, push-button functionality, and keypad scanning techniques with this engaging quiz! Ideal for electronics enthusiasts and students alike.

Multiple choice and checkbox questions
Explore concepts related to MSP430 microcontrollers
Perfect for self-assessment and learning

15 Questions4 MinutesCreated by TestingTech42

To determine which input port pin requested an interrupt, you can check which bits are set in the interrupt flag register (PxIFG) within your ISR. Is there also another way to do it?

Yes, by checking the value of the interrupt enable register (PxIE)

Yes, by checking the value of the interrupt vector register (PxIV)

No, checking the PxIFG is the only possibility.

Yes, by checking the value of the input register (PxIN)

Consider a push-button with an external pull-down resistor connected to pin P2.0. Which TWO of the following statements are true?

The push button is active-high.

The push button is active-low.

P2.0 is 1 when push-button is NOT pressed.

P2.0 is 0 when the push-button is NOT pressed.

For a smooth key pressing experience on the keypad, your program uses a scanning frequency of ca. 50 Hz (scans per seconds). What would be the result of increasing this frequency, for instance, to 3000 Hz?

It will result in a reduced power consumption, since key pressed can be read faster.

It will result in a higher power consumption, since the program size will be larger.

It will allow multiple keypresses to be identified.

It will result in a higher power consumption, since more instructions per second are executed.

An active-low push button is connected to pin P2.0. Which instruction causes the MCU to wait until the button is pressed?

While(P2IN & 0x01 == 0x01);

While(P2OUT|0x00==0x01);

While(P2OUT&0x00==0x01);

While(P2IN|0x01==0x01);

What is the result for c in the following code segment? Signed char c = 120; c += 10;

C = 130

C = -130

C = -3

C = -126

You enabled the internal pull-up/down resistor for input pin P2.7 in the P2REN register. What is the command to enable the pull-up option for the corresponding pin?

P2SEL |= BIT7;

P2IN |= BIT7;

P2OUT |= BIT7;

P2REN |= BIT7;

The interrupt edge select register (PxIES) allows to assert an interrupt either on the rising or on the falling edge. Is there a way to assert an interrupt on both edges (rising and falling)?

Yes, by toggling the corresponding PxIES bit inside the interrupt service routine(ISR).

No, because after each interrupt occurance the GIE flag must be manually set again.

No, because an interrupt is only allowed to occur either on the rising or on the falling edge.

Yes, by toggling the corresponding PxIFG bit inside the interrupt service routine (ISR).

Is it possible to change the interrupt priorities of the MSP430 Port1 pins?

No, it's only possible for Port 2

Yes, by using P1ES register.

Yes, by using P1SEL register.

No, interrupt priorities are fixed.

You have 4 push-buttons connected to the input pins P1.0, P2.0, P2.1, P2.2. All buttons should trigger interrupts. How many separate Interrupt Service Routines (ISRs) does your code require for this?

What is the result for c in the following code segment? Unsigned char c = 0x88; c ^= 0x77;

C = 0x00

C = 0x88

C = 0xFF

C = 0x77

Recall how the keypad is connected to the MSP430 in the Lab (rows connected to output pins, columns connected to input pins). Does this connection allow the scanning algorithm to detect more than one pressed key?

No, it is not possible.

Yes, regardless which keys are pressed.

Yes, but only if the pressed keys are in the same column.

Yes, but only if the pressed keys are in the same row.

An active-low LED is connected to pin P8.4. Which instruction will turn-off the LED?

P8OUT |= 0x04;

P8OUT &= ~(0x10);

P8OUT |= 0x10;

P8OUT &= ~(0x04);

What is the result for c in the following code segment? Unsigned char c = 0xF7; c |= 0x0F;

C = 0xFF

C = 0xF0

C = 0x00

C = 0x07

2103 Quiz

Microcontroller Interrupts and Keypad Quiz

More Quizzes