This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

Debug monitor


The Debug Monitor sample shows a basic configuration of debug monitor feature.

The source code shows how to:

  1. Configure registers to enable degugging in debug monitor mode

  2. Specify custom interrupt to be executed when entering a breakpoint


Your board must:

  1. Support Debug Monitor feature (available on Cortex-M processors with the exception of Cortex-M0)

  2. Have an LED connected via a GPIO pin (these are called “User LEDs” on many of Zephyr’s Supported Boards).

  3. Have the LED configured using the led0 devicetree alias.

Building and Running

Build and flash Debug Monitor as follows, changing reel_board for your board:

west build -b reel_board samples/subsys/debug/debugmon
west flash

After flashing the board enters a breakpoint and executes debug monitor exception code. The LED starts to blink, indicating that even though the processor spins in debug monitor interrupt, other higher priority interrupts continue to execute.