Definitely can add a lot of parts around it. Then again the board would cost more and everyone would pay for that feature, whiter they used it or not..
It would be less expensive to just add it to the cape on an add needed basis and not on every single pin. Gerald On Tue, Sep 8, 2015 at 12:02 PM, rattus <gehlv...@gmail.com> wrote: > Completely understood; however, assuming one could meet board area and > timing constraints, it might be possible to wrap the processor with a > circuit prophylactic, as it were... > > I've also been part of several ARM-based core silicon projects, and it > would have been possible for that (i.e. consistent pre-reset I/O state) to > have been addressed at the chip level. > > Mike > > On Tuesday, September 8, 2015 at 5:56:32 AM UTC-6, Gerald wrote: >> >> I/O pin functionality is a function of the processor. Not the board. >> >> Gerald >> >> On Mon, Sep 7, 2015 at 10:05 PM, rattus <gehl...@gmail.com> wrote: >> >>> On Monday, September 7, 2015 at 6:52:12 PM UTC-6, Graham wrote: >>>> >>>> Well, by definition, the boot programming pins are going to have the >>>> pull-ups / pull-downs, so you know what they are going to be doing, until >>>> over-ridden. >>>> >>>> Most processors start up with the programmable pins as inputs, then >>>> move to the configured state. >>>> >>> >>> If it were so... but it seems with such an abundance of modes and pins, >>> a number of the pins I am using are in a variety if input, output, hi-Z and >>> I/O defaults at powerup, most often with pullup or pull-downs. The good >>> news is, I've added enough gating and the additional fast-starting Vdd to >>> avoid conflicts. SPI attached peripherals (powered early) all need commands >>> shifted in to drive outputs, so that's safe too. >>> >>> Now for the *next* Beaglebone, innocuous I/Os would be a great feature... >>> >>> Anything else can be dangerous to the pins. But, as Charles says, RTFM. >>>> >>> >>>> If you are concerned, use the bus-isolation /transmission-gate chips, >>>> power them early, supply your own pull-ups/pull-downs, and switch the >>>> connection on when SYS_RESETn goes high. Then you are unconditionally >>>> safe, and in-control. >>>> >>>> --- Graham >>>> >>> >>> Thanks, >>> >>> Mike >>> >> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Gerald ger...@beagleboard.org http://beagleboard.org/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
