How long does the 32.768kHz crystal oscillator need when it starts running?

[Alice]

Hi,

For the LE1,I found that 32.768kHz crystal oscillator need long time(about 350ms) to running,I must do some delay(about 350ms) for the software then use the RTC,or the time will not correct.The time is more 300ms than the real time.If I use the 32.768 RC,the problem will not appear.

Is there any register that I can know the 32.768kHz crystal oscillator is running?

such as: while(hal_clk_get_16m_source() != HAL_CLK_XOSC16M) { // Wait until 16 MHz crystal oscillator is running }

In fact,I have done like this:

while(!(CLKLFCTRL & 0x40)); however,it seems that it is invalid.

Thank you very much.

Best regards, Alice

[Håkon Alseth]

Hi,

You can read the phase of the clock in the CLKLFCTRL register. Try something like this:

  while((CLKLFCTRL&0x80)==0x80); // Read
  while((CLKLFCTRL&0x80)!=0x80); // Phase

Best regards Håkon

[Alice]

Thanks for your reply.I have tried it,but it seems that it is invalid