MSP430's default CPU clock frequency

Henry yu

Prodigy 60 points

Hi,

We have a question about MSP430's default CPU clock frequency.

In TI RTOS, the default CPU clock frequency is 8192000 (MCLK=SMCLK=819200).

Can we adjust this frequency by external circuit?

Can MSP430 calibrate this frequency internally? we would like to know tolerance of this frequency.

Thanks

Henry

over 4 years ago

0 Urica Wang over 4 years ago

TI__Intellectual 2650 points

Hi Henry,

That depends on the particular device you're using. These values are described in the device datasheet, and you can refer to the source code examples on Resource Explorer for examples on frequency calibration, etc.

Thanks,

Urica Wang

0 Henry yu over 4 years ago in reply to Urica Wang

Prodigy 60 points

Hi Urica,

According to the MSP430F552x datasheet, the DCO frequency temperature drift is 0.1%/C

How to do the calibration for MSP430F552x DCO?

Thanks

Henry

0 Urica Wang over 4 years ago in reply to Henry yu

TI__Intellectual 2650 points

Hi Henry,

You can find this information in the device family User's Guide https://www.ti.com/lit/slau208, specifically section 5.2.6 "Digitally Controlled Oscillator (DCO)" and section 5.2.6.1 "Adjusting DCO Frequency".

Resource Explorer also has several code examples that show how to calibrate the DCO [link], specifically the MSP430F55xx_USC code examples.

Thanks,

Urica Wang

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MSP430's default CPU clock frequency