From: Arlen R. <ar...@gm...> - 2012-01-10 13:56:58
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Ben: The OMAP processor expects all I/O lines to be driven only after the proper power up sequence has completed, and that all I/O lines to the OMAP processor stop being driven before the proper power down sequence begins. If you choose to drive any I/O lines before the power up sequence has started, or continue to do so while shutting power off to the processor, you are using the OMAP processor out of the manufacturer recommendations, and TI does not define how the device will behave. Thus, it is a good idea to not use the device in this way. The TI TPS65950 Power Management IC provides the SYSEN signal that goes high when it is allowable to start driving the I/O lines. Use this signal to enable driving all I/O to the OMAP processor, and you will be fine. Thanks, -Arlen On Mon, Jan 9, 2012 at 6:01 PM, Keane, Ben (STRX) <ben...@ka...> wrote: > Is this protection only required for UART or for all GPIO pins? > >> -----Original Message----- >> From: ebtschi [mailto:ewa...@ni...] >> Sent: Monday, 9 January 2012 8:13 PM >> To: gum...@li... >> Subject: Re: [Gumstix-users] Protecting UART ports while SYSEN is low >> >> Hi Lucas, >> >> thank you for your reply. >> >> I also found this thread: >> http://gumstix.8.n6.nabble.com/Overo-module-seems-dead-root-ca >> use-td641684.html >> >> One user also used series resistors to solve the problem. As >> far as I can see there is a pullup needed anyway, to avoid >> detecting a break condition on the UART line. Could this also >> be a problem? Moving from high-impedance to high at a time >> defined by SYSEN (or a little bit after that) seems a bit unsafe. >> >> -- >> View this message in context: >> http://gumstix.8.n6.nabble.com/Protecting-UART-ports-while-SYS >> EN-is-low-tp3274358p3511548.html >> Sent from the Gumstix mailing list archive at Nabble.com. >> >> -------------------------------------------------------------- >> ---------------- >> Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't >> need a complex infrastructure or vast IT resources to deliver >> seamless, secure access to virtual desktops. With this >> all-in-one solution, easily deploy virtual desktops for less >> than the cost of PCs and save 60% on VDI infrastructure >> costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> ______________________________________________________________________ >> CAUTION: This message was sent via the Public Internet and >> its authenticity cannot be guaranteed. >> > > PROPRIETARY: This e-mail contains proprietary information some or all of which may be legally privileged. It is intended for the recipient only. If an addressing or transmission error has misdirected this e-mail, please notify the authority by replying to this e-mail. If you are not the intended recipient you must not use, disclose, distribute, copy, print, or rely on this e-mail. > > ------------------------------------------------------------------------------ > Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex > infrastructure or vast IT resources to deliver seamless, secure access to > virtual desktops. With this all-in-one solution, easily deploy virtual > desktops for less than the cost of PCs and save 60% on VDI infrastructure > costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users |