Input capture mode in Embedded C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Input Capture Mode in embedded C?

Input Capture Mode is a feature in microcontrollers that records the exact time when an input signal changes, using a timer. It helps measure signal timing precisely.

beginner

Which hardware component is mainly used in Input Capture Mode?

A timer/counter module is used to capture the time of an input event, like a rising or falling edge on a pin.

intermediate

How does Input Capture Mode help in measuring pulse width?

It records the timer value at the start and end of a pulse, allowing calculation of the pulse duration by subtracting these values.

intermediate

What is the role of an interrupt in Input Capture Mode?

An interrupt triggers when the input event occurs, so the program can quickly read the captured timer value without missing the event.

advanced

Give a simple example of configuring Input Capture Mode in embedded C.

Example: Configure timer, set input capture pin, enable capture on rising edge, enable interrupt, and read timer value in ISR.

What does Input Capture Mode primarily measure?

A The exact time an input signal changes

B The voltage level of an input pin

C The frequency of the output signal

D The temperature of the microcontroller

Input Capture Mode records the timer value when an input signal changes, capturing the exact time of the event.

Which event typically triggers the input capture in embedded systems?

A A change in input pin signal (rising or falling edge)

B A timer overflow

C A reset button press

D A power failure

Input capture is triggered by a signal edge (rising or falling) on the input pin.

Why are interrupts used with Input Capture Mode?

A To reset the microcontroller

B To slow down the timer

C To turn off the input pin

D To immediately handle the captured timer value

Interrupts allow the program to quickly respond and read the captured timer value without delay.

What hardware module is essential for Input Capture Mode?

A Analog-to-Digital Converter

B Timer/Counter module

C UART module

D PWM generator

The timer/counter module records the time when the input event occurs.

How can Input Capture Mode help measure pulse width?

A By counting the number of pulses

B By measuring voltage levels

C By capturing timer values at pulse start and end

D By generating PWM signals

Capturing timer values at the start and end of a pulse allows calculation of pulse duration.

Explain how Input Capture Mode works in a microcontroller and why it is useful.

Think about how a stopwatch records exact times when a button is pressed.

Describe the steps to configure Input Capture Mode in embedded C.

Consider what hardware and software settings are needed to catch and use the input event time.