STR75x RTC in STANDBY mode

[Vagni]

Posted on August 11, 2010 at 10:03

My application on STR750F uses the internal RTC. My board applies the Power Scheme N. 3 (single external 5.0V power source).

I need to preserve the date-time of the RTC when my board is powered off.

From the UM0191 Reference Manual I see I could enter in STANDBY mode when the power is switched off. The RTC continues to run, because it is powered by the internal Vbackup.

Could you please confirm to me that VDD_IO must always be present also when the STR750F is in STANDBY mode with only the internal RTC running, otherwise the RTC would loose its counter value at the next power-on of my board?

[Vagni]

Posted on August 11, 2010 at 10:29

When in STANDBY mode, how have I to keep the NRSTIN pin? If I keep NRSTIN low, does RTC continue to run preserving its counter value?