#1) Is the Vsystem signal on J5 a direct connection to the Vsystem signals on J1/J4? #2) Do all the Vsystem pins, on J1 and J4, go directly to the PMIC "Vbat" regulator inputs as shown in Figure 4-1 of the TPS65950 datasheet and all the Vbat* named signals from Table 2-2? #3) J1 pin 65 is labeled POWERON but it didn't look like it was used on the Tobi or Summit expansion boards. Per the TPS65950 datasheet (Table 2-1) this signal is referenced to the VBAT power input on the TPS65950 and had no internal pullup. So does it have a pullup to Vsystem on the Overo COM? #5) J1 pin 1 is labeled N_MANUAL_RESET. Does that go to the NRESWARM pin on the PMIC?
Thanks
C W Hinkle
Ascendant Engineering Solutions
Austin, TX
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On 10/3/09, Clyde Hinkle <[hidden email]> wrote:
> #1) Is the Vsystem signal on J5 a direct connection to the Vsystem signals > on J1/J4? Yes. > #2) Do all the Vsystem pins, on J1 and J4, go directly to the PMIC "Vbat" > regulator inputs as shown in Figure 4-1 of the TPS65950 datasheet and all > the Vbat* named signals from Table 2-2? Yes. > #3) J1 pin 65 is labeled POWERON but it didn't look like it was used on the > Tobi or Summit expansion boards. Per the TPS65950 datasheet (Table 2-1) this > signal is referenced to the VBAT power input on the TPS65950 and had no > internal pullup. So does it have a pullup to Vsystem on the Overo COM? IIRC this pin is an output from a master PMIC chip so no pullup is needed. > #4) J4 pin 41 is labeled GPIO114_SPI1_NRQ. I don't see SPI NRQ as an OMAP > defined function. So that is just OMAP GPIO114 and can be used for other > GPIO purposes, right? Yes. > #5) J1 pin 1 is labeled N_MANUAL_RESET. Does that go to the NRESWARM pin on > the PMIC? I am not sure about this one, but yes that is most likely. Lowering GPIO30 will also reset the board. > Thanks > > C W Hinkle > Ascendant Engineering Solutions > Austin, TX ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ gumstix-users mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/gumstix-users |
> > #3) J1 pin 65 is labeled POWERON but it didn't look like it was used on
the > > Tobi or Summit expansion boards. Per the TPS65950 datasheet (Table 2-1) this > > signal is referenced to the VBAT power input on the TPS65950 and had no > > internal pullup. So does it have a pullup to Vsystem on the Overo COM? > > IIRC this pin is an output from a master PMIC chip so no pullup is needed. In case we are speaking about the PWRON pin on TPS65950 (I assume we are), this is always an input and referenced to VBAT as described in the original post. In case the pull-up isn't mounted on the Overo module itself you would need it externally on your own board. I would however assume it's mounted on the Gumstix (but I don't know) since it's working and since a low going pulse on this signal will switch on the board after it has been switched off. Can anybody from Gumstix please comment on this? Best regards and thanks Søren --- SSC Solutions ApS - Denmark - www.ssc-solutions.dk ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ gumstix-users mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/gumstix-users |
I am experiencing infrequent power up problems with Overo Air modules. 10% of my systems will fail to boot after a week of use. The problem is the PMIC not turning on power to the OMAP. I am floating PWRON on my main board, per some of the previous discussion here. I posted this question to a TI OMAP forum, and received this answer today from Gandhar who is active on the TI site:
"Do you not connect anything to PWRON? Floating SYSEN output is ok. PWRON should be connected to VBAT via a switch or via pull-up. It should not be left floating. You will surely have issues due to this." I'm going to add a pullup to PWRON, but this problem is so infrequent, it will be difficult to tell if this fixes anything. If someone from Gumstix can confirm if PWRON is pulled up on the module, that would be very helpful, so I'm not guessing anymore! Thanks. |
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