Firmware Fundamentals — question 6 of 10
Write a real answer. It is graded against the question's rubric, and the mastery movement is computed by the same engine the product uses. Scoring here is deterministic rather than model-written, so this page costs nothing to run and nothing is saved. In a track built from your own posting, the same rubric is graded by the model, which is what produces feedback about your reasoning rather than about coverage.
On an 8-bit microcontroller, a timer interrupt increments a 16-bit millisecond counter every tick. In the main loop you read that same variable to time an event. Occasionally you get an elapsed time that's wildly wrong - one 16-bit read comes back nowhere near what it should be. What's actually happening at the instruction level, and how would you fix it?