3 ms·
>ATX 5V is really unsuitable for USB power, and can play tricks on you. Why? I don't think current motherboard duplicate 5V converter. >you may end up with im
by garaetjjte 7y ago
>ATX 5V is really unsuitable for USB power, and can play tricks on you.
Why? I don't think current motherboard duplicate 5V converter.
>you may end up with improperly inited board, and 3.3V ICs booting up before the CPU.
Why it cannot just hold reset line for these chips high until CPU started?
- Gibbon1 7y agoA lot of peripheral IC's don't have reset lines. Sometimes this is a big big problem. You can end up with failure to come up maybe 1 in 10,000. Exactly the sort of thing that shows up late in development or worse in the field. Tip: If anyone tells you power supply and reset sequencing is 'easy' ignore them.
- dezgeg 7y agoHolding chips in reset is not the only thing that matters. Complex chips may have power-sequencing restrictions; for example 1.8V power rail might need to be up before 3.3V, otherwise the chip gets damaged.