For systems using microprocessors or computers there are usually numerous power supplies. If a power supply fails the power manager circuits may, as a minimum, force a shutdown. For maintenance and troubleshooting it is very desirable to know which power supply failed and the type of failure condition (over-voltage or under-voltage).
This reference design presents a solution that records the supply fault condition in non-volatile memory so the fault(s) can read back at some later time. This solution is fast, reliable, and cost effective because, it is based on a Power Manager II, MachXO, and nonvolatile SPI flash memory.