TDA4AEN-Q1: Does the Scratch Registers value changes (reset) after SoC cold start or warm start?

Part Number: TDA4AEN-Q1

Dear Expert.

Customer want to stores a piece of value (variable) in SoC, and they want this value do not change after SoC warm and cold reset.

Does "Scratch Registers" (SCRATCHx) in RTC support it? 

Does it have any R/W limition for "Scratch Registers"

Because customer want to implement "firmware upgrade over CAN", so they need an  Non-Volatile Memor to save some flags in SoC

Thank You.

Gibbs