SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
This reset signal is the MAIN domain warm reset request (active LOW) controlled by the RESET_REQz HW pin.
When LOW is detected, reset hardware generates an interrupt to processors (A53SS/R5FSS/M4FSS/DMSC-L/ICSSG) so that they can complete the reset isolation sequence before reset is propagated.
This isolation sequence isolates the MCU domain from the MAIN domain so that it is protected against spurious glitches when the MAIN domain is reset.
This sequence also ensures that reset isolated-configured modules such as PRU_ICSSG are in reset isolation before propagating the warm reset to MAIN domain.
Entire MCU domain is reset isolated.
MCU IOs are not effected.
This is a MAIN domain reset request. First, the reset isolation sequence is applied and then the reset is propagated.
All modules in MAIN domain are reset except for reset isolated modules and MAIN domain CTRLMMR register bits which are reset only on MAIN_PORz.
IOs are not effected.
All processor cores are reset (A53SS, DMSC-L, and R5FSS).
Reason for this reset is captured in the CTRLMMR reset source register CTRLMMR_RST_SRC. After reset is de-asserted, device will boot-up. During device boot-up, R5FSS secondary boot loader will read the reset status and MCU ACTIVE MAGIC WORD registers and reconfigure the MCU domain/M4FSS processor accordingly.
The MAIN_RESET_REQz reset sequence is described below.
The MAIN_RESET_REQz reset signal is equivalent to the RESET_REQz HW Pin.
This diagram shows the timing between the MAIN_RESET_REQz reset signal and the internal MAIN_RESETz (MAIN domain warm reset) signal.
MAIN_RESETSTATz:
The MAIN_RESETSTATz pin indicates the MAIN domain internal reset status (active LOW). This is a reflection of the reset status after the MAIN_RESET_REQz reset signal (RESET_REQz HW Pin) is asserted.
When LOW, it indicates that the MAIN domain is in internal reset state.
When HIGH, it indicates that the MAIN domain is out of internal reset state.
For more details see MAIN_RESETSTATz Status Pin.