TechnicalInterior and Mirror Cameras: The Stale Frame Problem
A mirror-replacement camera rarely fails by going blank. It fails by showing you a well-formed picture of a road that has moved on. Most of the chain answers a different question. A link CRC proves the pixels arrived intact. A register readback proves the sensor is configured. A watchdog proves the imaging task is scheduled, and a task republishing its last buffer is scheduled perfectly. So teams add a frame counter, usually in the software that receives frames. That proves only that this software is running: it keeps counting while the sensor sits dark. Even minted at the sensor, a counter is metadata: it travels next to the pixels, not inside them. A stage that re-stamps on publication can attach a fresh number to old pixels, and a header-only check waves it through. Placement earns you sequence coverage. Claiming the picture is current is a bigger claim than most safety cases support. New article on what that costs in detection budget and where the ISO 21448 boundary falls.