--------------------------------------------
On Thu, 1/5/17, Justin Pearson <[email protected]> wrote:

 Subject: Re: [beagleboard] Clock running slow when gpio0[11] pulled high
 To: [email protected]
 Date: Thursday, January 5, 2017, 1:19 AM
 
 Thanks
 Gerald! Did I reference the correct version (CircuitCo's
 GitHub)?
 -Justin
 On Wed, Jan 4, 2017 at 3:15
 PM, Gerald Coley <[email protected]>
 wrote:
 That brings tears to my eyes seeing someone
 quoting the manual.
 Yes,
 don't screw up the SYS_BOOT pins.
 
 Gerald
 
 On Wed, Jan 4, 2017 at 5:12 PM,
 Justin Pearson <[email protected]>
 wrote:
 Expanding
 Chad's comment, in the Beaglebone Black System Reference
 Manual (Rev B, Jan 20, 2014)
 https://github.com/CircuitCo/B
 eagleBone-Black/blob/390c46a03
 e039661aeca6eab22e6c383d8d537f
 8/BBB_SRM.pdf
 "Figure 39. Processor Boot
 Configuration" in "Section 6.8 Default Boot
 Options" says that the top two bits of the SYSBOOT
 register, SYSBOOT[15:14], seem to select which oscillator is
 used (19.2MHz, 24MHz, 25MHz, 26MHz). 
 "Figure 38. Processor Boot
 Configuration Design" shows that SYS_BOOT14 and 15 are
 physically lcd_data14 and 15.
 "Table 12. Expansion Header P8
 Pinout" shows that lcd_data14 and 15 are GPIO0[10] and
 GPIO0[11] in MODE0.
 Section "8.1.1 LCD Pins"
 contains the warning:
 "These pins are also the
 SYSBOOT pins. DO NOT drive them before the SYS_RESETN signal
 goes high. If you do, the board may not boot because you
 would be changing the boot order of the
 processor."
 In
 Fig 39, I see that SYSBOOT[15:14] == 01b results in 24 MHz,
 whereas 11b results in 26MHz, whose 8% difference may
 account for your ~5 sec offset per minute. (If 24MHz is the
 default, I'm not sure.)
 Best,Justin
 
 
 On Wednesday, January 4, 2017 at 5:12:24 AM
 UTC-8, cmbaker3 wrote:
   
     
   
   
     Johan,
 
       That pin is used during the boot operation.
 
       Check in the SRM for the default boot options.
 
       
 
       On 1/4/2017 5:39 AM, Johan Ribenfors wrote:
 
     
     
       We've recently found a
 strange problem.  Repeatable
         across all eleven boards we've tried so far.
         
 
         
         When pin 32 on P8 (gpoi0[11]) is pulled high
 via a resistor
           on boot, the clock on the BBB runs ~7000 seconds
 slow a day.
           (~5 seconds a minute)
         
 
         
         If the pin is pulled low or left floating on
 boot, the
           clock keeps time.
         
 
         
         The device tree overlay was set to 0x37 for
 this pin - fast
           slew, output, pullup, mode 7, but changing this
 has no effect.
         
 
         
         We were using Debian 7.9 with various programs
 installed, a
           few device tree overlays applied and a custom cape
 when we
           noticed this, but it's still the case using
 the Debian 8.6
           image with no modifications, no dto and no
 cape.
         
 
         
         We haven't been able to find anything
 online and don't
           really know where to start looking.
         
 
         
         Any ideas?
       
       -- 
 
       For more options, visit http://beagleboard.org/discuss
 
       --- 
 
       You received this message because you are subscribed
 to the Google
       Groups "BeagleBoard" group.
 
       To unsubscribe from this group and stop receiving
 emails from it,
       send an email to [email protected] m.
 
       To view this discussion on the web visit https://groups.google.com/d/ms
 gid/beagleboard/e0647cb0-ac27-
 44ed-a11b-a6f71b7ef077%40googl egroups.com.
 
       For more options, visit https://groups.google.com/d/op
 tout.
 
     
     
 
     
 
     
     -- 
 
       Chad Baker
       Memphis, TN
   
 
 
 
 
 
 -- 
 
 For more options, visit http://beagleboard.org/discuss
 
 --- 
 
 You received this message because you are subscribed to the
 Google Groups "BeagleBoard" group.
 
 To unsubscribe from this group and stop receiving emails
 from it, send an email to beagleboard+unsubscribe@google
 groups.com.
 
 To view this discussion on the web visit https://groups.google.com/d/ms
 gid/beagleboard/79bac7d6-3011-
 44b5-95ac-61c43cb8525c%40googl egroups.com.
 
 For more options, visit https://groups.google.com/d/op
 tout.
 
 
 
 
 -- 
 Gerald
  
 [email protected]
 http://beagleboard.org/[email protected]
 
 
 
 
 
 -- 
 
 For more options, visit http://beagleboard.org/discuss
 
 --- 
 
 You received this message because you are subscribed to a
 topic in the Google Groups "BeagleBoard" group.
 
 To unsubscribe from this topic, visit https://groups.google.com/d/
 topic/beagleboard/mFBxTSWl7Ro/ unsubscribe.
 
 To unsubscribe from this group and all its topics, send an
 email to beagleboard+unsubscribe@
 googlegroups.com.
 
 To view this discussion on the web visit https://groups.google.com/d/
 msgid/beagleboard/CAHK_S%2Bc0% 3DS__LXv5wbF_%
 2B9xP9chLWxErTbCvcxOyejQv8pASZ w%40mail.gmail.com.
 
 For more options, visit https://groups.google.com/d/
 optout.
 
 
 
 
 
 
 -- 
 
 For more options, visit http://beagleboard.org/discuss
 
 --- 
 
 You received this message because you are subscribed to the
 Google Groups "BeagleBoard" group.
 
 To unsubscribe from this group and stop receiving emails
 from it, send an email to [email protected].
 
 To view this discussion on the web visit 
https://groups.google.com/d/msgid/beagleboard/CABCHBhJ9ga9%3DGa5%2BupB-y2y59DZDBqLsM2Rhv0Y5dL5tJbwuqg%40mail.gmail.com.
 
 For more options, visit https://groups.google.com/d/optout.
  dec - Ludovic Napoleon Bonaparte se proclama imparat cu numele de Napoleon al 
lII- Ion Bratianu inainteaza lui Napoleon al

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/beagleboard/128570793.51906.1483572715515%40mail.yahoo.com.
For more options, visit https://groups.google.com/d/optout.

Reply via email to