>
> Robert,
>
> What do you need or want to use the PRUs for ? These pins you're talking
> about are probably shared with the HDMI pins, but are not the only pins the
> PRU have access to. These pins are probably the pins the single cycle(5ms)
> access to
> , where the PRU's can access any pin on the board, just not with single
> cycle access. More like 3+ cycles if memory serves correctly.
>
> My answers this morning did not include this earlier because I was not
> quite awake yet. . .


Put more acurately.


   - The pins you're asking about are shared with the header pins for the
   HDMI framer.
   - Your LCD uses HDMI, so in order to use those pins, you would have to
   disable HDMI.
   - The PRUs can access any GPIO pin on the board, but the ones shared
   with HDMI( and a few others ) can be accessed by the PRU in a single PRU
   cycle - 5ms.
   - The rest of the pins can still be accesses by the PRU's, just with a
   higher access latency. 3-5 cycles if I remember right.


So to solve this problem of yours, you have some options. Disable the HDMI
pins, and re-enable for PRU GPIO access, for full speed GPIO, or use
different pins and access the pin slower . . .Or perhaps the remaining
single cycle access pins raming for PRU0 / PRU1 are enough for what you
need ?

So again, I ask. WHat ddo you need the PRU's for ? ;)

On Fri, May 6, 2016 at 12:58 PM, William Hermans <[email protected]> wrote:

> Robert,
>
> What do you need or want to use the PRUs for ? These pins you're talking
> about are probably shared with the HDMI pins, but are not the only pins the
> PRU have access to. These pins are probably the pins the single cycle(5ms)
> access to
> , where the PRU's can access any pin on the board, just not with single
> cycle access. More like 3+ cycles if memory serves correctly.
>
> My answers this morning did not include this earlier because I was not
> quite awake yet. . .
>
> On Fri, May 6, 2016 at 12:53 PM, Robert Jonathan Šimon <
> [email protected]> wrote:
>
>> I have another Question on PRUs. It has 9 pins for first PRU and 15 pins
>> for the second PRU (according to this schematic
>> <http://beagleboard.org/support/bone101/#headers-pru>). Is there any
>> option to expand number of pins, which I cand use by the PRUs?
>>
>> Dne pátek 6. května 2016 18:25:14 UTC+2 Robert Jonathan Šimon napsal(a):
>>
>>> Ok. Great. Thanks for your time.
>>>
>>> Dne pátek 6. května 2016 18:21:47 UTC+2 William Hermans napsal(a):
>>>>
>>>> Better yet, I'll tell you what's better to do. Contact the manufacturer
>>>> of that screen, and ask what you're options are.
>>>>
>>>> If you're lucky, it could be possible to rewrite the device tree
>>>> overlay file for that screen to work using alternate pins.
>>>>
>>>> If you're unlucky, you'll have to buy a different kind of screen.
>>>>
>>>> On Fri, May 6, 2016 at 9:18 AM, Robert Jonathan Šimon <
>>>> [email protected]> wrote:
>>>>
>>>>> Sorry, i send the wrong link. On this link
>>>>> <https://www.soselectronic.cz/productdata/15/37/24/153724/4DCAPE-70T_datasheet_R_1_2.pdf>,
>>>>> there is a picture, where you can see precisely which pin it is using
>>>>>
>>>>> Dne pátek 6. května 2016 18:12:17 UTC+2 William Hermans napsal(a):
>>>>>>
>>>>>> Ok, so, I do not have time to read through all the literature for
>>>>>> that screen. Which pins does it use, what is the specific function of 
>>>>>> each
>>>>>> pin, and what "protocol" does the screen use ?
>>>>>>
>>>>>> Is it one of those modified 9pin SPI + GPIO screens ?
>>>>>>
>>>>>> On Fri, May 6, 2016 at 9:02 AM, Robert Jonathan Šimon <
>>>>>> [email protected]> wrote:
>>>>>>
>>>>>>> I have this LCD screen
>>>>>>> <https://www.soselectronic.cz/products/4dcape-70t#tabs-6> and it
>>>>>>> user most of the second PRU pins and one of the first PRU unit. I am not
>>>>>>> sure, if this is problem or not.
>>>>>>>
>>>>>>> Dne pátek 6. května 2016 17:59:11 UTC+2 William Hermans napsal(a):
>>>>>>>>
>>>>>>>> *Hi,*
>>>>>>>>> *I am starting to play with PRU on BBB, and I noticed, that when I
>>>>>>>>> want to use PRU on BBB and on the same time use LCD display through 
>>>>>>>>> GPIO, i
>>>>>>>>> cant (they use the same pins). Is there any workarounds?*
>>>>>>>>>
>>>>>>>> *Thanks a lot*
>>>>>>>>
>>>>>>>> I suppose that depends on how far you're willing to go, and changes
>>>>>>>> you're willing to make. You can buy a different LCD screen, and perhaps
>>>>>>>> even type of screen that uses different peripherals.
>>>>>>>>
>>>>>>>> But you can start by telling us which LCD screen you're using, and
>>>>>>>> being more verbose as to how this LCD is connected. exactly which pins 
>>>>>>>> are
>>>>>>>> required, etc.
>>>>>>>>
>>>>>>>>
>>>>>>>> On Fri, May 6, 2016 at 8:41 AM, Robert Jonathan Šimon <
>>>>>>>> [email protected]> wrote:
>>>>>>>>
>>>>>>>>> Hi,
>>>>>>>>> I am starting to play with PRU on BBB, and I noticed, that when I
>>>>>>>>> want to use PRU on BBB and on the same time use LCD display through 
>>>>>>>>> GPIO, i
>>>>>>>>> cant (they use the same pins). Is there any workarounds?
>>>>>>>>> Thanks a lot
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> For more options, visit http://beagleboard.org/discuss
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>>>>>>>>> .
>>>>>>>>> For more options, visit https://groups.google.com/d/optout.
>>>>>>>>>
>>>>>>>>
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>>>>>>> .
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>>>>>>> For more options, visit https://groups.google.com/d/optout.
>>>>>>>
>>>>>>
>>>>>> --
>>>>> For more options, visit http://beagleboard.org/discuss
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>>>>> You received this message because you are subscribed to the Google
>>>>> Groups "BeagleBoard" group.
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>>>>> an email to [email protected].
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>>>>> .
>>>>>
>>>>> For more options, visit https://groups.google.com/d/optout.
>>>>>
>>>>
>>>> --
>> For more options, visit http://beagleboard.org/discuss
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>>
>> For more options, visit https://groups.google.com/d/optout.
>>
>
>

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