MUOTUC,
Very nice work!!!!!! We all appreciate your hard work! Thank you.
dattaway- 08-21-2005
This will be useful for when I convert the batteries to lithium and need to calibrate the battery low voltage divider.
terramir- 12-06-2005
ok two questions A are the contacts for the main chip on the other side of the board (ergo do they poke through) and B what stops those among us that are really really good solders to solder in a higher capacity flash chip? :P
or wouldn't that work because the lines used for the 128 mb chip would be different or you would need more lines to reach let's say the upper half of the storage on a 256 mb or 512 mb chip? :?
terramir
PS: if youwant to use a Li-ion rechargable battery on this thing you should be able to do it with just a diode(one with a small .3V drop gemanium should do just fine) or no adjustments at all a little secret full 1.5 V batteries are actually around the 1.7V-1.75V range depending on how sensitive this thing is. A full li-ion cell might hurt it, but once the first 20% are used and it's down to 3.6V-3.7V you shouldn't have a problem but usually 4.2V (or if you choose a 4.1V Li-ion even better :D ) should be safe. If you put in a small germanium diode in series you should be safe. I don't think a 4.2 V one would brick the thing even without a voltage drop diode! (although I would wait for some input from the crack electronics experts here on that one) One thing I do know are li-ion's (hehe did a lot of research on those suckers still working on the code for my pic li-ion charging chip though :D ) (got 50 of those thing's laying around prismatic cell's 4.1V max 3.6V nominal that I wantto usefor projects Although I already use two for my li-ion driven eGo (mp3 player) manual charging is a bit*h though
brite_eye- 12-28-2005
Can someone verify that the NC (no connects) on the flash chip are either connected to ground or just left floating (unlikely)?
boclo- 12-28-2005
Glad this thread was bumped. interesting, trying to read the schmatics.
shootME- 12-29-2005
Can someone verify that the NC (no connects) on the flash chip are either connected to ground or just left floating (unlikely)?I think NO CONNECT means exactly that ... NOT CONNECTED to ANYTHING.
brite_eye- 12-30-2005
I vaguely recalled that someone indicated that wasn't always true. After using the divergences sticky for google searches specifying flash nc ground - I found the following old post by MUOTUC:
forumer.com/viewtopic.php?p=2930#2930" target="_blank">http://camerahacks.10.forumer.com/viewtopic.php?p=2930#2930
And since he (MUOTUC) did include ground for pin 6 on schematic - I think the other NC are probably just floating.
shootME- 12-30-2005
I just took another look at the data sheet for the HYNIX - HY27UA081G1M Flash chip,
and the info about all the pins shows the ones that say NC are "NOT Connected Internally"
if it's showing DU it means "DO NOT USE"
I was always told that when a pin isn't connected internally, you can connect something to there if you want,
as a connection point for a separate part of the circuit without screwing up the chips function.
I've never done this, but if these chips have pins NOT CONNECTED INTERNALLY, then it's like those pins are floating on the board,
'cause there's NO connection within the chips internal circuitry to those particular pins (NC)
so there CAN BE a pin pad, or NOT BE a pin pad for the NC pins, it doesn't matter...
like you put two wires on your desk, connected to nothing. 8) it doesn't matter if you connect one end of each wire to something
'cause nothing is connected to the other ends. :P :D
There are quite a few NC pins on this chip, but there ARE differences with the 8-BIT version and the 16-BIT version...
some of the 16-BIT versions pins that show as NC on the 8-BIT, are NOT NC on the 16-BIT chip...
and the same for the WSOP1 version of the chip... maybe this is what MUOTUC was referring to...
I don't know, I'm just reading the Data Sheet PDF. :roll: :)
:wink:
texaspyro- 12-30-2005
Nope, never connect anything to an NC pin. Future chips may have something connected there.
Nope, never connect anything to an NC pin. Future chips may have something connected there.
well ... future chips would need to be re-mounted when the old one is removed, so at that point you could remove any connection to the chips NC pins, ... :roll:
and brite_eye is right ... I checked the PDF and all the versions of the Hynix chip has pin 6 as NC.
Spooky HUH. :roll: :shock: :lol: :?: :!: so Pure Digital isn't following texaspyro's advice, or the schematic is wrong. :D
:roll:
texaspyro- 12-30-2005
The idea is that if the manufacturer makes mods to their chip or releases a new and improved one that uses the NC pin for something, you won't have locked yourself into a corner by connecting things to NC pins.
Sometimes you design a product that allows alternate source components that may have conflicting pinout requirements... then you might have something connected to a pin that says NC. Otherwise it's best to leave NC pins NC'ed.
shootME- 12-30-2005
Sometimes you design a product that allows alternate source components that may have conflicting pinout requirements... then you might have something connected to a pin that says NC. Otherwise it's best to leave NC pins NC'ed.TRUE ... this was why I originally said I've never connected anything to pins marked NC ... !
I was just thinking out-loud, for brite_eye's sake.
brite_eye- 12-30-2005
Based on Corscaria's comments it looks like PD may have designed these to support other smartmedia with spare pages always enabled.
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