SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The RTC provides three general-purpose registers (RTC_SCRATCHx_REG) that can be used to store 32-bit words -- these registers have no functional purpose for the RTC. Software using the RTC may find the SCRATCHx_REG registers to be useful in indicating RTC states. For example, the RTC_SCRATCHx_REG (RTC_SCRATCH0_REG, RTC_SCRATCH1_REG, RTC_SCRATCH2_REG) registers may be used to indicate write-protection lock status or unintentional power downs. To indicate write-protection, the software should write a unique value to one of the RTC_SCRATCHx_REG registers when write-protection is disabled and another unique value when write-protection is enabled again. In this way, the lock-status of the registers can be determined quickly by reading the RTC_SCRATCHx_REG register. To indicate unintentional power downs, the software should write a unique value to one of the RTC_SCRATCHx_REG registers when RTC is configured and enabled. If the RTC is unintentionally powered down, the value written to the RTC_SCRATCHx_REG register is cleared.