Can an ESP8266 read it's own supply voltage?

[mmliam]

According to the ESP8266EX Data sheet

Pin 6, TOUT
ADC pin. It can be used to test the power-supply voltage of
VDD3P3 (Pin3 and Pin4) and the input power voltage of TOUT
(Pin 6). However, these two functions cannot be used
simultaneously.

The ADC has a 1v max input voltage that max's to 1024. Therefore, if indeed the ESP8266 can read it's own supply voltage would suggest that there must be an internal voltage divider.

Does anyone know whether indeed the ESP8266 can read it's own supply voltage, and if so, does micropython support this function?