SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
The VTM module outputs an alert signal (THERM_MAXTEMP_OUTRANGE_ALERT), when the device temperature goes beyond a maximum threshold.
This reset signal creates a MCU domain warm reset.
VTM alert will be active as long as the error condition (Device Temperature > Maximum Temperature Threshold) is still TRUE.
When the error goes away, VTM alert will be de-asserted and device will come out of warm reset.
This signal, when asserted HIGH, will cause a device warm reset similar to MCU_RESETz.
All modules in MCU domain are reset except for modules and MCU domain CTRLMMR bits which are reset only on MCU_PORz.
IOs are not effected.
This reset is active as long as the VTM alert is active.
When THERM_MAXTEMP_OUTRANGE_ALERT is de-asserted, the MCU domain needs to be reconfigured by R5FSS (secondary boot loader) in the MAIN domain.
All modules in the MAIN domain are reset except for modules and CTRLMMR bits which are reset only on MAIN_PORz.
IOs are not effected.
All processor cores are reset (A53SS, DMSC-L, and R5FSS).
When THERM_MAXTEMP_OUTRANGE_ALERT is de-asserted, the device goes through full initialization procedure. The reason for this reset is captured in the CTRLMMR reset source register CTRLMMR_RST_SRC.
VTM alert use-case example:
VTM sends out a warning signal before generating the Max Temp Alert.
There are 2 different threshold settings for max temperature limits.
The first one has a lower threshold which will generate an interrupt to the processor for taking action to reduce frequency, turn-off power domains, etc. This should eventually lower the temperature and avoid the Max Temp Alert.
If the interrupt does not fix the rising temperature, then VTM will issue a Max Temp Alert. This will cause a device warm reset. The VTM Max Temp Alert will be active as long as die temperature is above the programmed threshold.
Device warm reset will default certain power domains to off mode (default at power-up). This should eventually lower the die temperature further.
Software can read the reset status register to poll on the cause of the warm reset. If it is from VTM, then it can wait for additional time before turning on the power domains.