MSP430F5252: Uart configuration drift

Clement Guillou1

Part Number: MSP430F5252

Hello,

I'm having an issue that I can't explain with my product.

I use an MSP430F5252 with TI-RTOS (tirtos_msp43x_2_20_00_06) and when I set the Uart driver as recommended by the datasheet and this :

I sometimes get corrupted data.

{
    .outputBaudrate = 9600,
    .inputClockFreq = 32768,
    .prescalar = 3,
    .hwRegUCBRFx = 0,
    .hwRegUCBRSx = 3,
    .oversampling = 0
},

But if I set this config below, it seems to be ok :

{
    .outputBaudrate = 9600,
    .inputClockFreq = 32768,
    .prescalar = 3,
    .hwRegUCBRFx = 0,
    .hwRegUCBRSx = 4,
    .oversampling = 0
},

Is there any reason that would explain such a thing ?

Thanks for your help,

Clement

over 6 years ago

0 Srinivas Lingam over 6 years ago

TI__Expert 7395 points

Hi Clement,

The User's guide (www.ti.com/.../slau208) does have the following information in section 36.3.10.1 Low-Frequency Baud-Rate Mode Setting:

"Incrementing or decrementing the UCBRSx setting by one count may give a lower maximum bit error for any given bit. To determine if this is the case, a detailed error calculation must be performed for each bit for each UCBRSx setting."

That might explain why 4 is giving better results than 3.

Srinivas

0 Clement Guillou1 over 6 years ago in reply to Srinivas Lingam

Intellectual 300 points

Ok, so if I understand this line correctly it means : If it works better in this particular setting, then it is the good setting.

I should keep this incremented setting then ?

Thank you Srinivas

0 Srinivas Lingam over 6 years ago in reply to Clement Guillou1

TI__Expert 7395 points

Hi Clement,

That is also my interpretation. If 4 is working better, maybe it is better to keep that configuration.

Srinivas

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MSP430F5252: Uart configuration drift