Enabling and disabling interrupts in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable global interrupts.

Embedded C

sei(); // Call the function to [1] interrupts

Drag options to blanks, or click blank then click option'

Adisable

Benable

Ccheck

Dclear

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing enable with disable

Using functions that clear flags instead

The sei() function enables global interrupts in embedded C.

2fill in blank

medium

Complete the code to disable global interrupts.

Embedded C

cli(); // Call the function to [1] interrupts

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Acheck

Benable

Cset

Ddisable

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing disable with enable

Using functions that set flags instead

The cli() function disables global interrupts in embedded C.

3fill in blank

hard

Fix the error in the code to enable interrupts.

Embedded C

void enable_interrupts() {
    [1]();
}

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Asei

Bcli

Cint_enable

Dinterrupt_on

Attempts:

3 left

💡 Hint

Common Mistakes

Using cli() instead of sei()

Using non-standard function names

The correct function to enable interrupts is sei(). Using cli() disables them.

4fill in blank

hard

Fill both blanks to disable interrupts and then enable them again.

Embedded C

void toggle_interrupts() {
    [1]();
    // some code
    [2]();
}

Drag options to blanks, or click blank then click option'

Acli

Bsei

Cenable

Ddisable

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the order of enable and disable

Using incorrect function names

First, cli() disables interrupts, then sei() enables them again.

5fill in blank

hard

Fill all three blanks to check if interrupts are enabled, and disable them if yes.

Embedded C

if ([1] & (1 << [2])) {
    [3]();
}

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ASREG

BI

Ccli

Dsei

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong register or bit names

Confusing enable and disable functions

The SREG register holds the interrupt flag I. If set, interrupts are enabled. Then cli() disables them.