Dear all,
I want to use the SNVS RTC with backup battery on imx6ul. I was able to enable it in kernel and device tree. From user space I can read it (hwclock -r) and set it to system time (hwclock -w). However, it runs way to fast, around +8 seconds faster per minute. This is more than 137ms per second. According to iMX6UL reference manual there is an RTC calibration register, however the maximum possible calibration value is 16/32768=488us per second, so no way I can compensate it this way. I know that internal clocks are quite inaccurate compared to external crystals, but I don't believe the difference is that big.
Does anyone have an idea what the problem could be?
Thanks and regards
已解决! 转到解答。
Hi Philipp
according to Table 11. Oscillator and clock recommendations
Hardware Development Guide for the i.MX 6UltraLite Applications Processor
"..on-chip 40 kHz oscillator. The tolerance is ± 50%."
https://www.nxp.com/docs/en/user-guide/IMX6ULHDG.pdf
Best regards
igor
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Hi Philipp
according to Table 11. Oscillator and clock recommendations
Hardware Development Guide for the i.MX 6UltraLite Applications Processor
"..on-chip 40 kHz oscillator. The tolerance is ± 50%."
https://www.nxp.com/docs/en/user-guide/IMX6ULHDG.pdf
Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
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