Hi Their design is hardly unique in not having a dedicated supervisory part in it. There are a *lot* of designs that work very well using basically the same parts they use, without using a reset chip.
Without a lot of digging into exactly what is going on, there isn’t much of a way to be sure of a fix. One very real possibility is: The reason we *have* all these parts is that they have a bug in them, and were scrapped out because of it. Bob > On Jun 9, 2016, at 8:03 AM, Clint Jay <[email protected]> wrote: > > It would seem so bit I don't remember seeing a 'reset' chip in the 5680. > I'm wondering if there's scope to add one onto the rail that runs the PSD > and 80C320 to keep it in reset. > On 9 Jun 2016 13:00, "Bob Camp" <[email protected]> wrote: > >> Hi >> >> Based on the number of different ways there seem to be to corrupt the >> operating software >> in the FE Rb’s …. they seem to have a unique problem. There are a *lot* of >> devices >> using the same basic parts that don’t turn into a brick when this or that >> happens. >> >> Bob >> >>> On Jun 9, 2016, at 4:31 AM, Hal Murray <[email protected]> wrote: >>> >>> >>>> The ATTinys have brownout detectors in them that’s supposed to keep them >>>> from going bonkers during undervolt periods. >>> >>> Startup and/or brownout has long been a nasty problem area for digital >>> designers. >>> >>> In the old old days, there was typically a R/C delay on the reset pin to >> a >>> CPU. That screwed up when the power supply ramped up slowly enough. >> Most >>> old timers have that merit badge. >>> >>> Modern CPU chips often have specs like power must be OK for 200 ms before >>> releasing Reset. Anything like that will have at least one corresponding >>> power monitor chip with several supply voltage inputs and the appropriate >>> delay. >>> >>> The brownout side gets ugly when you look at the tolerances. The >> tolerance >>> on the power monitor subtracts from the power supply tolerances. >>> >>> There is another worm in the can. How long does it take for your >> oscillator >>> to get going? >>> >>> >>> >>> -- >>> These are my opinions. I hate spam. >>> >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
