Embedded Systems — question 4 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.
Stack sizing on small MCUs with no MMU is a routine sanity check before shipping firmware.
Your MCU has 1KB of stack allocated for a task. Baseline stack usage before any function calls is 200 bytes (locals in main plus saved registers). Each additional nested function call in your worst-case call chain adds 40 bytes of frame overhead, and a worst-case interrupt preemption at any point in that chain needs an extra 150 bytes for its own context and locals. What is the maximum call depth you can nest before you risk overflowing the stack?
This one resolves to a number. Give the value in the field below and your reasoning in the box — the number is checked exactly, by arithmetic.