Enabling and disabling interrupts in Embedded C - Mini Project: Build & Apply

Enabling and Disabling Interrupts in Embedded C

📖 Scenario: You are working on a simple embedded system that needs to control when interrupts are allowed to happen. Interrupts are signals that tell the processor to stop what it is doing and handle something important. Sometimes, you want to turn interrupts off to finish a task without interruption, and then turn them back on.

🎯 Goal: Build a small program that shows how to enable and disable interrupts using variables and functions in Embedded C.

📋 What You'll Learn

Create a variable to represent the interrupt status

Create a configuration variable to hold the interrupt mask

Write functions to enable and disable interrupts

Print the interrupt status after enabling and disabling

💡 Why This Matters

🌍 Real World

Embedded systems often need to control when interrupts can happen to avoid errors during critical tasks.

💼 Career

Understanding how to enable and disable interrupts is essential for embedded software developers working on microcontrollers and real-time systems.

1

Create the interrupt status variable

Create an unsigned int variable called interrupt_status and set it to 0 to represent that interrupts are initially disabled.

Embedded C

// Create an unsigned int variable called interrupt_status and set it to 0
// Your code here

Need a hint?

Use unsigned int interrupt_status = 0; to create the variable.

2

Create the interrupt mask configuration

Create an unsigned int variable called interrupt_mask and set it to 1 to represent the mask used to enable interrupts.

Embedded C

unsigned int interrupt_status = 0;
// Create an unsigned int variable called interrupt_mask and set it to 1
// Your code here

Need a hint?

Use unsigned int interrupt_mask = 1; to create the mask variable.

3

Write functions to enable and disable interrupts

Write two functions: enable_interrupts() and disable_interrupts(). In enable_interrupts(), set interrupt_status to interrupt_mask. In disable_interrupts(), set interrupt_status to 0.

Embedded C

unsigned int interrupt_status = 0;
unsigned int interrupt_mask = 1;

// Write the function enable_interrupts() to set interrupt_status to interrupt_mask
// Write the function disable_interrupts() to set interrupt_status to 0
// Your code here

Need a hint?

Define two functions that change the value of interrupt_status accordingly.

4

Print the interrupt status after enabling and disabling

Call enable_interrupts() and then print interrupt_status. Then call disable_interrupts() and print interrupt_status again. Use printf to display the values.

Embedded C

unsigned int interrupt_status = 0;
unsigned int interrupt_mask = 1;

void enable_interrupts() {
    interrupt_status = interrupt_mask;
}

void disable_interrupts() {
    interrupt_status = 0;
}

int main() {
    // Call enable_interrupts and print interrupt_status
    // Call disable_interrupts and print interrupt_status
    // Your code here
    return 0;
}

Need a hint?

Use printf("Interrupt status after enabling: %u\n", interrupt_status); to print the status.