They come up as inputs.

Gerald


On Mon, May 2, 2016 at 2:38 PM, <[email protected]> wrote:

> So, Gerald,
> Why do you think it is an acceptable condition to to have GPIO1_16
> fighting GPIO2_0 on boot up, and perhaps forever for the case that a BBB
> user doesn't happen to notice this condition, which violates the AM3358
> recommended operating conditions? Ref: TI SPRS717J –OCTOBER 2011–REVISED
> APRIL 2016 page 92, VOH and VOL, normal operation characteristics.
> John C.
>
> On Tuesday, June 4, 2013 at 3:29:51 PM UTC-4, Gerald wrote:
>>
>> Yes it is. I added the ability to bring out the MMC2 CMD
>> line. Unsoldering the resistor is what they are there for. No sadness
>> needed. Sadness only in the SW was unable to control the HW correctly.
>>
>> Gerald
>>
>>
>>
>> On Tue, Jun 4, 2013 at 2:18 PM, Juanjo <[email protected]> wrote:
>>
>>> Update,
>>>
>>> Indeed PIN9.15 on BBB is a _bit_ different than old BB. Seeing
>>> schematics one can see that T13 (GPIO2_0) is also connected on PIN9.15, on
>>> the original BB only R13 (GPIO1_16) was connected to pin 9.15.
>>>
>>> So now GPIO1_16 and also GPIO2_0 is connected to PIN9.15. Sadly T13
>>> (GPIO2_0) seems to start as GPMC or MMC2 or something that gets you
>>> 1.0-1.6V on this pin on start which could lead to problems on power up on
>>> some capes.
>>>
>>> By now I just desoldered R161 (which connects T13 to PIN9.15) but I´ll
>>> change my design to use another pin which do start at 0V on powerup.
>>>
>>>
>>> On Monday, June 3, 2013 5:35:22 PM UTC-4, Juanjo wrote:
>>>>
>>>> BTW,
>>>>
>>>> I must add that on my white BeagleBone I'm running the exact same
>>>> kernel that on the BBB which is 3.8.13-bone20. I was on understanding that
>>>> the DTS are applied the same on the BBW and BBB for 3.8.
>>>>
>>>> It seems that for 3.8.13 on the BBB the DTS that are loaded before any
>>>> overlay change PIN9.15 mux or just reset it to mode 0. But I cannot find
>>>> any mention to gpmc_a0 on those DTS/DTSI :(
>>>>
>>>> On Monday, June 3, 2013 5:25:00 PM UTC-4, Juanjo wrote:
>>>>>
>>>>> Thanks Gerald !
>>>>>
>>>>> On Monday, June 3, 2013 4:41:13 PM UTC-4, Gerald wrote:
>>>>>>
>>>>>> The 3.8 does not affect what is needed to control the pins, That is
>>>>>> all protected by hardware in the chip. The 3.8 kernel does affect how 
>>>>>> pins
>>>>>> are controlled with things like overlays. I suggest you read
>>>>>> the document located at https://docs.google.com/
>>>>>> document/d/17P54kZkZO_-JtTjrFuVz-Cp_RMMg7GB_8W9JK9sLKfA/pub . It
>>>>>> should answer some of your questions.
>>>>>>
>>>>>> Gerald
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Mon, Jun 3, 2013 at 3:32 PM, Juanjo <[email protected]> wrote:
>>>>>>
>>>>>>> Thanks Gerald,
>>>>>>>
>>>>>>> I managed to set the pin on early init on uBoot and it does work.
>>>>>>> But afterward when Kernel is booting it changes the pin back :( and keep
>>>>>>> that way until I set out direction on the GPIO using Linux gpio 
>>>>>>> interface.
>>>>>>>
>>>>>>> I wonder if the pin mux kernel parameters defined on
>>>>>>> http://processors.wiki.ti.com/index.php/AM335x_PSP_User's_Guide
>>>>>>> still applies to 3.8.X
>>>>>>>
>>>>>>> On Monday, June 3, 2013 3:06:28 PM UTC-4, Juanjo wrote:
>>>>>>>>
>>>>>>>> Guys,
>>>>>>>>
>>>>>>>> On my cape I use PIN9.15 (GPIO1_16) to control an ON/OFF process
>>>>>>>> through a NPN transistor. This cape worked just right on white BB. Now 
>>>>>>>> I´m
>>>>>>>> trying the cape on a new BBB I noted that the power on process is 
>>>>>>>> started
>>>>>>>> just when the BBB is powered up and I need to start the process after 
>>>>>>>> a few
>>>>>>>> conditions are met.
>>>>>>>>
>>>>>>>> I noted that on my white Beaglebone once power is up and uBoot
>>>>>>>> starts this PIN stay low just as expected (isn´t in SYSBOOT) but on 
>>>>>>>> the BBB
>>>>>>>> it starts at 1.0 - 1.6V which starts my process earlier than it should.
>>>>>>>>
>>>>>>>> I played in uBoot with "gpio clear 48" which do sets the pin low
>>>>>>>> but then the Kernel starts and it switch to 1.6V again and I´m setting 
>>>>>>>> pin
>>>>>>>> muxing through a DTBO which describes my cape. But the level goes low 
>>>>>>>> just
>>>>>>>> after I use "echo out > /sys/class/gpio/gpio48/direction" on
>>>>>>>> Linux. Even I forced the muxing of this pin to GPIO1_16 on uBoot and
>>>>>>>> recompile but somewhere is changed back to 1.6V on uBoot and in the 
>>>>>>>> Kernel
>>>>>>>> afterward.
>>>>>>>>
>>>>>>>> PIN9.15 is GPIO1_16, gmpc_a0, gmii_ and rmii_ something which AFAIK
>>>>>>>> isn't used for anything on the new BBB it isn't a SYSBOOT pin so I 
>>>>>>>> can't
>>>>>>>> figure why this pin is starting at 1.6V and even changing it to 0V 
>>>>>>>> using
>>>>>>>> uEnv.txt after Kernel boot it goes to 1.6V again.
>>>>>>>>
>>>>>>>> Any help would be appreciated.
>>>>>>>>
>>>>>>>> Thanks
>>>>>>>>
>>>>>>>> --
>>>>>>> For more options, visit http://beagleboard.org/discuss
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>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Gerald
>>>>>>
>>>>>> [email protected]
>>>>>> [email protected]
>>>>>> http://beagleboard.org/
>>>>>> http://circuitco.com/support/
>>>>>>
>>>>> --
>>> For more options, visit http://beagleboard.org/discuss
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>>>
>>>
>>
>>
>>
>> --
>> Gerald
>>
>> [email protected]
>> [email protected]
>> http://beagleboard.org/
>> http://circuitco.com/support/
>>
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-- 
Gerald

[email protected]
http://beagleboard.org/
[email protected]

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