how do we differentiate between PowerON Reset vs External Watchdog Reset in STM8AF5288

[DMega.1]

How can we differentiate between Power ON Reset vs MCU Reset initiated by an external watchdog device?

I mean is there a Memory Area in STM8AF5288 MCU that retains state after MCU Reset compared to Power ON Reset?

I cannot find the source of the MCU Reset as the External Watchdog output is connected to the MCU Reset pin.

[AA1]

You can't. Use the internal watchdog 

If you want to find the source of the MCU reset, disconnect the external watchdog.

[DMega.1]

Could we use the noinit ram section variables to distinguish between external watchdog applied MCU Reset versus Power ON Reset? Is it possible with STM8AF5288 MCU ?