i.MX ProcessorsのトピックPCF85063AT/AY | Oscillator stop flag setting issue

PCF85063AT/AY | Oscillator stop flag setting issue

Anmol — Mon, 04 Sep 2023 07:43:05 GMT

We constructed an IMx8x board with a PCF85063AT/AY RTC (schematic attached). The problem is that when I turn on the power supply, the oscillator stop bit is set. and the IMx8x driver reports power failure and discards the time. On the oscilloscope, I noticed misbehave in crystal pulse. The RTC OSCI pin is pink, and the OSCO pin is blue. When I switched the power supply from off to on, the pulse rate increased. How can we fix it?

Re: PCF85063AT/AY | Oscillator stop flag setting issue

guoweisun — Tue, 05 Sep 2023 07:37:11 GMT

The oscillator is considered to be stopped during the time between power-on and stable
crystal resonance. This time can be in the range of 200 ms to 2 s depending on crystal
type, temperature, and supply voltage.

so you can operate the OS bit after this period(200ms to 2s) when power on this RTC.

Re: PCF85063AT/AY | Oscillator stop flag setting issue

Anmol — Wed, 06 Sep 2023 15:27:17 GMT

Hi guoweisun

Thanks for your response. yes i read the same in datasheet. So the driver i am using read this oscillator bit as corruption in time and show "power loss detected, time is invalid". so i there any way to not have oscillator stop bit get set making seconds register invalid for my driver.

Re: PCF85063AT/AY | Oscillator stop flag setting issue

guoweisun — Wed, 06 Sep 2023 22:45:59 GMT

Seems no method to stop this OS bit set if any oscillator stop happened.