Reset Introduction
A reset is
designed to bring a device or subsystem into a known state. Resets occur after power up
events, as well as through software and hardware reset requests. This section introduces
the device reset capabilities and functionality.Device Resets
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 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, PLLCTRL and PSC, this includes ARM®
Cortex®- M4F
MCU Processor (M4FSS).
- MAIN Reset Domain: Managed by the
MAIN Domain, PLLCTRL and PSC, this includes the high performance application Arm
Cortex-A53 cores (A53SS), Device Management and Low Power Management (DM R5F),
Security Controller (SMS0
- Dual core M4F) and Programmable
Real-Time Unit Subsystem (PRUSS0).
- A subset of MAIN and MCU domains is
logically grouped ad WKUP domain. This domain is always on and is responsible
for device low power management. DM R5F is located in this domain. See Figure 6-15.
- Security controller SMS has 2
submodules:
- TIFS (TI Foundational
Security) has a dedicated M4F responsible for device security
- HSM (Hardware Security
Mode) has a dedicated M4F responsible for customer/application centric
security (such as AutoSAR)
Figure 6-13 illustrates
the high-level reset domain partition.