From: <gs...@gm...> - 2005-03-14 11:09:02
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Just a quick Q from a newbie. Im building a usb port from scratch. The signali i get on D+, D- from the USB host are 5V can the Gumstix use these lavels or do i have to scale them down to 3.3 V ? The schematisc on Gumstic.com shows them using 5V but i just wanted to be sure before risking frying the thing :) Cheers TinTin |
From: Gordon K. <go...@gu...> - 2005-03-14 15:35:01
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Gert, You can review the PXA Design doc (which we list on the left panel of the wiki) Section 4, which describes the interface officially. My summary of it is that the PXA takes the USB Data signals directly into the D+ and D-, which are not GPIO lines. Intel does list an optional resistor if any trace impedence matching turns out to be needed for the board. However, all the other signals would go to GPIO lines and do need to be level-shifted. Good luck, Gordon Gert Sørensen wrote: >Just a quick Q from a newbie. >Im building a usb port from scratch. The signali i get on D+, D- from >the USB host are 5V can the Gumstix use these lavels or do i have to >scale them down to 3.3 V ? > >The schematisc on Gumstic.com shows them using 5V but i just wanted to >be sure before risking frying the thing :) > >Cheers TinTin > > >------------------------------------------------------- >SF email is sponsored by - The IT Product Guide >Read honest & candid reviews on hundreds of IT Products from real users. >Discover which products truly live up to the hype. Start reading now. >http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >_______________________________________________ >gumstix-users mailing list >gum...@li... >https://lists.sourceforge.net/lists/listinfo/gumstix-users > > |