SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
The Device Power-on-Reset (POR) is controlled by the external pin MCU_PORz. This pin is driven by an external (off-chip) "Power-Good" Circuit or Power Management IC (PMIC). The MCU_PORz pin should be held active LOW (0) during the entire power-up phase. The device should be held in reset until all power supplies are stable with an additional a delay for the High Frequency Oscillator (HFOSC0) clock to stabilize.
The SoC is divided into two separate functional Reset Domains: MCU Reset Domain and MAIN Reset Domain (each containing specific processing cores and peripherals).
MCU Reset Domain: Managed by the MCU Domain PSC, this includes Arm Cortex-M4F MCU Processor (M4FSS).
MAIN Reset Domain: Managed by the MAIN Domain PSC, this includes the high performance application Arm Cortex-A53 cores (A53SS), Device Management and Security Controller (DMSC-L), real-time performance Arm Cortex-R5 cores (R5FSS), and Programmable Real-Time Unit Subsystem and Industrial Communication Subsystem - Gigabit (PRU_ICSSG) Cores.
The MCU and MAIN domains can be configured to have independent warm reset pins via software: MCU_RESETz and RESETz_REQ. By default, these two pins have the same effect and will act as a warm reset source for both MAIN and MCU domains. When the MCU domain is configured for reset isolation, MAIN domain resets will only reset the MAIN domain and the MCU domain will remain unaffected by all MAIN domain resets.
This flowchart explains the high-level reset use case.