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Rockbox mail archiveSubject: Re: USB On-The-Go (OTG) (was: Re: 2nd ATA Device on JB20 Recorder)Re: USB On-The-Go (OTG) (was: Re: 2nd ATA Device on JB20 Recorder)
From: Andrew Jamieson <andrew.jamieson_at_projectlab.net>
Date: Thu, 23 Jan 2003 10:49:20 +1100 USB OTG requires special controllers, and is not supported by either of the USB chips Archos uses. Andrew Jamieson ----- Original Message ----- From: "Francesco Grassi" <frangras_at_tin.it> To: <rockbox_at_cool.haxx.se> Sent: Thursday, January 23, 2003 10:25 AM Subject: USB On-The-Go (OTG) (was: Re: 2nd ATA Device on JB20 Recorder) > Hi guys, > I found these links: > http://www.semiconductors.philips.com/buses/usb/products/otg/ > > http://www.semiconductors.philips.com/buses/usb/products/otg/tutorial/index. > html > [...] > Point-to-Point Connectivity The OTG Supplement extends the USB standard to > enable point-to-point communication between two USB devices: one OTG device > and another OTG or traditional USB device. Because the two devices still > maintain the roles of host and peripheral, OTG point-to-point communication > is not to be confused with peer-to-peer. Unlike traditional USB, OTG allows > only one peripheral at a time to be connected to the device acting as host. > OTG devices do support USB hubs, a traditional way of enabling multiple USB > peripherals to share a single USB host connection. However, some OTG > functionality such as swapping host/peripheral roles and peripheral session > requests are not supported across today's USB hubs. > > USB OTG device types range from battery-powered handheld products to > non-portable peripherals. While initial device roles (host/peripheral) are > defined by how they are cabled together, some OTG devices can switch roles > through the host negotiation protocol (HNP) without changing the cabling. > > Figure 3: OTG enables point-to-point connectivity between peripherals > without a traditional PC host. > > To better understand how new OTG devices and features add to existing USB > functionality, a quick review of USB device terminology follows. > > The A-device is the default host at the start of a session. It supplies > power to VBUS. > The B-device is the default peripheral at the start of a session. > To these, the OTG Supplement adds the OTG device and defines two types: a > dual-role device and a peripheralonly device. > [...] > > > http://www.usb.org/developers/onthego/ > > > > Maybe it could be useful for our objective... > > > > FG > > > > -----Messaggio originale----- > Da: owner-rockbox_at_cool.haxx.se [mailto:owner-rockbox_at_cool.haxx.se]Per > conto di roland > Inviato: mercoledì 22 gennaio 2003 23.35 > A: rockbox_at_cool.haxx.se > Oggetto: Re: 2nd ATA Device on JB20 Recorder > > > jep, > otherwise CF2IDE Adapters like these: > http://www.flashmemory.com.au/shop/shopdisplayproducts.asp?id=3&cat=FlashMem > ory+Disk+Drives > would be a bit dangerous :) > > First I was unsure about this because I read contradictory comments - but > at least > http://www.compactflash.org/faqs/faq.htm#dvs approved that CF supports BOTH > voltages. > > Regards > Roland > > > ----- Original Message ----- > From: "Stuart Tedford" <stuart.tedford_at_piresearch.co.uk> > To: <rockbox_at_cool.haxx.se> > Sent: Wednesday, January 22, 2003 5:29 PM > Subject: RE: 2nd ATA Device on JB20 Recorder > > > > >-----Original Message----- > > >From: Andrew Jamieson > > > > > >And dont forget that CF cards use 3.3V power, not 5V. > > > > No, CF cards allow for both 3.3 and 5V supply. > > > > Stu. > > > Received on 2003-01-23 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |