KL26Z & RTC

[simonatoumberto]

I use

MKL26Z256VLL4 micro -  clock 8Mhz

I use  as RTC_CLKIN (pin PTC1) the output of pin PTC3

I set MGGIRCLK with souce 32KHz IRC

As you can see in Clock and RTC SET 

I have a RTC time error - about 2 minutes x day

I see that PTC3 output a 32898 hz signal

instaead of waiting 32768 hz. (see RTCinput.jpg)

I have tried to adjust this signal 

changing the value of  slow internal reference clock but no result

Can you give me some support?

Thanks

Umberto

[Hui_Ma]

Hi,

Please refer KL26 datasheet about the internal slow clock accuracy data:

If customer want more accuracy RTC clock, it need to use external 32.768KHz crystal or oscillator.

Thank you for the attention.

Have a great day,
Ma Hui

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