Case History Notebook
Saved 25,000 Misprogrammed MCUs Challenge: 25,000 mask-programmed microcontrollers in an elder-care alarm reporting system were known to have an elusive bug in their firmware, causing the system to occasionally crash without warning or indication. Action: Despite the fact that no provisions for a watchdog timer were provided, and no detectable events took place while the program was running properly, an inexpensive (~$1) circuit was designed to detect the crash and reset the processor when needed. Result: The manufacturer was able to avoid scrapping $250,000 worth of microcontroller ICs and circumvent the 12-week production delay that ordering new parts would have caused.