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FRDM K82F uart problem

Question asked by Grzegorz Mikitiuk on Sep 19, 2018
Latest reply on Sep 24, 2018 by Mark Butcher

Hello after a while i still didn't find answer to my question and i'm still unable to set proper baudrate on lpuart0.

Before i start i want to say that i read almost every post about lpuart on the forum, config is correct except baudrate and clocking.

 

Formula from datasheet:

Baudrate clock/(SBR*(OSR+1))

 

So i noticed that only  value of 16 and 32 can be set in OSR field (15 and 31), any other value results in getting 16/32. Also  in SBR field there is  always "1"  on third spot from LSB,  so  if i set 8 result in 12, 1 results in 5, 12 results in 12 etc.

 

Also there is no way to set FLL/PPL or IRC48M in SIM_SOPT2, value in the register doesn't want to change or clear, only fast internal oscillator can be set.

 

Knowing these problems i can easily predict what baudrate i will get but it's so problematic because setting any of typical baudrates highter than 9600 seems impossible.

 

 

Noticed that on  custom K80 board  also on FRDM-K82.

 

Any ideas what might be wrong?

Maybe it's a bug?

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