Kinetis Microcontrollers中的主题 Re: Understanding ICS_C3 register in KEA-128

Understanding ICS_C3 register in KEA-128

vigneshbalaji — Thu, 26 May 2016 12:40:47 GMT

Hi,

I want to understand ICS_C3 register of KEA-128.

I want to know, what values of ICS_C3 register correspond to what value of Internal Reference Clock???

Re: Understanding ICS_C3 register in KEA-128

Robin_Shen — Mon, 30 May 2016 02:46:40 GMT

Hi VIGNESH,

Please refer "Yes, OSDA can trim the reference of internal clock source!".

Best Regards,

Robin

Re: Understanding ICS_C3 register in KEA-128

vigneshbalaji — Mon, 30 May 2016 07:08:54 GMT

Hi Robin,

I looked through the document. It explains about Trim value but it does not explain about what values of ICS_C3 or ICS_C4 registers correspond to what values of Internal Reference in Khz?

Can you give me Clarity on that?

Re: Understanding ICS_C3 register in KEA-128

Robin_Shen — Wed, 01 Jun 2016 09:06:28 GMT

Hi VIGNESH,

The factory trimmed value of ICS_C3 and ICS_C4 vary from one MCU to another, although the frequency of IRC are default equal to 37.5kHz.

Even you trim the different chip to the same frequency, but the internal ICS_C3,ICS_C4 may have different data, the data is not fixed to different chip.

Manufacturing process yealds to frequency deviation, that is why all MCU devices are factory programmed with a trim value in a reserved memory location. This value is uploaded to the ICS_C3 register and ICS_C4[SCFTRIM] during any reset initialization. For finer precision, trim the internal oscillator in the application and set ICS_C4[SCFTRIM] accordingly.

About the ICS_C3 and ICS_C4, you can read below field descriptions.

Best Regards,

Robin