[ULP-3.19] ULP Coprocessor And Touch Sensors Can Not Be Used In Deep-sleep Mode If RTC_PERIPH Power Domain Is Powered Up
Description
The main operating clock for the ULP coprocessor and touch sensor is FAST_CLK. In Deep-sleep mode, if the RTC_PERIH power domain (RTC Peripherals) remains powered up, the ULP coprocessor and touch sensor will receive the wake-up signal earlier than the clock management module. This causes them to operate under SLOW_CLK for a period before switching to FAST_CLK, leading to inaccuracies in the operating clock. Therefore, in Deep-sleep mode, if RTC_PERIH is powered up, the ULP co-processor and touch sensor cannot be used.
Workarounds
If the user wants to utilize the ULP coprocessor and touch sensor functionalities, the RTC_PERIPH must remain powered down in Deep-sleep mode. Note that during this time, the EXT0 wake-up is not available, as it only operates when RTC_PERIPH is powered up.
Users need to make a trade-off between using the EXT0 wake-up function and the ULP coprocessor and touch sensor functionalities:
If the EXT0 wake-up function is needed: The RTC_PERIPH power domain must remain powered up, and the ULP coprocessor and touch sensor functionalities will not be available.
If the ULP coprocessor and touch sensor functionalities are needed: The RTC_PERIPH must remain powered down, and the EXT0 wake-up function will not be available.
Solution
No fix scheduled.