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> >>> In any case, keep in mind usb hw changes, without them Neo won't be usb > >>> certified and that's a really big issue for a sdk-like device on > >>> manufacturers point of view. We can chat about it later ;-) > >> Definitely the first step is putting that in front of Wolfgang to see > >> how critical it is all things considered. Even if we can't > >> conform on this first run we need to as soon as possible. > > > > afaict, I didn't see an otg transceiver on neo's hw. Am I right ? > > If that's true, we won't ever have otg support. > > > > The connector is piece of cake, just change from mini-b to micro-ab > > (mini shouldn't be used anymore), but the transceiver involves much more > > expenses and changes to the hw design. Is there any space in the pcb for > > a new chip? And what about the i2c bus ? (otg transceivers are mostly > > connected through i2c and/or ulpi interfaces). > > I don't know much about OTG, but we currently have some discretes > allowing to control 15K pulldowns on to the USB +/- and 1K5 to 3.3V. We > have a separate pump to make 5V for being host power that can be enabled > and an overcurrent detect. > > The CPU has a USB host controller and device controller logic that can > operate on the same phy pins. > > Is this adequate? If it isn't and the transceiver replaces some or all > of the existing discretes, then there is probably room. This sounds adequate... but I'm concerned about id pin. Device should switch to host role automaticaly upon detecting id-pin grounded (micro-a connector attached to micro-ab receptacle) and switch to peripheral upon detecting id pin floating (micro-b connector attached to micro-ab receptacle). D+/D- terminations will probably be inside the otg transceiver, so as the charge pump, just gotta look what is in the market. Make some ISPXXXX is enough. if I could take a look at neo's schematics, I could at least wonder if an otg transceiver would be necessary of not. The datasheet/trm/whatever-doc from samsung cpu would also be handy. - -------------- Somebody in the thread at some point said: >> >> Is this adequate? If it isn't and the transceiver replaces some or all >> >> of the existing discretes, then there is probably room. > > > > This sounds adequate... but I'm concerned about id pin. Device should > > switch to host role automaticaly upon detecting id-pin grounded (micro-a > > connector attached to micro-ab receptacle) and switch to peripheral upon > > detecting id pin floating (micro-b connector attached to micro-ab > > receptacle). I think this detection will be OK since we can discover it from an ADC on the PMU via a resistor network (ID is in the middle of 100K to 0V + 39K to switched 3.3V). But it means polling this which is fine, I don't have much idea how to handle that in terms of role switching... a daemon / kernel thread? But it sounds possible. > > D+/D- terminations will probably be inside the otg transceiver, so as > > the charge pump, just gotta look what is in the market. Make some > > ISPXXXX is enough. If we are okay with what we have, we would leave it alone probably. So far I understood only the connector change is mandatory. ... - -Andy -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFH0/ZPOjLpvpq7dMoRAh71AJ9vtp5gfreJoXle/f/DooU8d4cUTwCeNjqW SX0dVlvBNHg6XsrEIwEn1PI= =EmG2 -----END PGP SIGNATURE-----
