So where do I change this?  In the device tree overlay?
I am just not comfortable on linux.  Use to direct control coding a PIC.


On Fri, Jun 6, 2014 at 10:25 PM, <[email protected]> wrote:

> I'm unsure how close to the hardware you're working, but it looks like the
> UART baud rate generator is using 13x oversampling when you were expecting
> 16x oversampling.  This is controlled by MODESELECT field in the UART's
> MDR1 register.
>
> So long as you're using the standard internal clock rates, the UARTs take
> a 48MHz clock as input, divide that down by the divisor you provide (UART
> registers DLH and DLL), then use the resulting clock to oversample each
> pixel period by either 13x or 16x.  Since you are trying to get 1Mbaud, a
> divisor of 3 with 16x oversampling would get you there.  It appears as if
> you have a divisor of 3 with 13x oversampling producing approximately
> 1.23Mbaud.
>
> One small change and you may be good to go.
>
> On Friday, June 6, 2014 5:45:39 PM UTC-7, Charles Kerr wrote:
>>
>> I setup my serial ports on the BBB to have a 1Mbaud rate.  However, when
>> I look at the output on the logic analyzer, I see the baud rate is more
>> like 1.214 MBaud.   This of course is too much deviation for my serial
>> transmission to sync  up.  I tried setting a custom baud rate, and that
>> just fails completely.  I wanted to use all four uarts.  If I need to, I
>> could bit bang it from the PRU (but then limit myself to two versus four).
>>  Is there a way to setup a more accurate baud rate on the BBB?
>>
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