In this PDN, the PMIC devices have the
following configured power states:
- Standby
- Active
- MCU Only
- Pwr SoC Error
- Retention
In Figure 6-1, the configured PDN power states are shown, along with the transition conditions
to move between the states. Additionally, the transitions to hardware states, such
as SAFE RECOVERY and LP_STANDBY are shown. The hardware states are part of the fixed
device power Finite State Machine (FSM) and described in the TPS6594-Q1 Power
Management IC (PMIC) with 5 Bucks and 4 LDOs for Safety-Relevant Automotive
Applications Data Sheet, see Section 8.
When the PMICs transition from the FSM
to the PFSM, several initialization instructions are performed to disable the
residual voltage checks on both the BUCK and LDO regulators, set the
FIRST_STARTUP_DONE bit and clear the VCCA OV and UV masks which are set in the
static configurations, Table 5-8. After these instructions are executed the PMICs wait for a valid ON Request
before entering the ACTIVE state. The definition for each power state is described
below:
STANDBY
The PMICs are powered by a valid supply on the system power rail (VCCA >
VCCA_UV). All device resources are powered down in the STANDBY state. EN_DRV
is forced low in this state. The processor is in the Off state, no voltage
domains are energized. Refer to the Section 6.3.2 sequence description.
The STANDBY state is also entered when an error occurs and the PMIC
transitions out of the PFSM mission states and into the FSM states. When the
device returns from the FSM state the to PFSM the first state is represented
by STANDBY with all of the resources powered down and EN_DRV forced low. The
sequence Section 6.3.1 is performed before the PMIC leaves the PFSM and enters the FSM state
SAFE_RECOVERY.
ACTIVE
The PMICs are powered by a valid supply. The PMICs are fully functional and
supply power to all PDN loads. The processor has completed a recommended
power up sequence with all voltage domains energized in both MCU and Main
processor sections. Refer to the Section 6.3.8 sequence description.
MCU_ONLY
The PMICs are powered by a valid supply. Only the power resources assigned
to the MCU Safety Island are on. VDD_DDR, which is enabled via GPIO4 remains
on when trigger I2C_7 is high and is turned off during the transition to the
MCU_ONLY state when I2C_7 is low. Refer to the Section 6.3.7 sequence description.
Pwr SoC Error
The PMICs are powered by a valid supply. Only the power resources assigned
to the MCU Safety Island are on. Refer to the Section 6.3.5 sequence description. The only active trigger is 'B', requiring the PMICs
to return to the MCU_ONLY mode. The return to MCU_ONLY mode and eventually
ACTIVE mode is only recommended after the interrupts which caused the
SOC_PWR_ERROR have been cleared.
Retention
The PMICs are powered by a valid supply. Only GPIO4 remains high, which
enables VDD_DDR, all other domains are off to minimize total system power.
EN_DRV is forced low in this state. Refer to the Section 6.3.9 sequence description.