The MCA implements a real-time clock (RTC) in its firmware. On the ConnectCore 8M Mini the internal CPU RTC is disabled because the MCA implementation handles power consumption more efficiently.

To keep the date during power-off you must connect a coin cell battery to the board.

Kernel configuration

You can manage the MCA RTC driver support through the following kernel configuration option:

  • Digi ConnectCore SOMs Micro Controller Assist RTC (CONFIG_RTC_DRV_MCA)

This option is enabled as built-in on the default ConnectCore 8M Mini kernel configuration file.

Kernel driver

The MCA GPIO driver is located at:

File Description


MCA RTC driver

Device tree bindings and customization

The MCA RTC device tree binding is documented at Documentation/devicetree/bindings/rtc/digi,mca-rtc.txt.

RTC inside the MCA

ConnectCore 8M Mini device tree
mca_cc8m: mca@63 {


	rtc {
		compatible = "digi,mca-cc8m-rtc";