SLVUCF3 March   2022 DRA829V , LP8764-Q1 , TDA4VM , TPS6594-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2Device Versions
  4. 3Processor Connections
    1. 3.1 Power Mapping
    2. 3.2 Control Mapping
  5. 4Supporting Functional Safety Systems
    1. 4.1 Achieving ASIL-B System Requirements
    2. 4.2 Achieving up to ASIL-D System Requirements
  6. 5Static NVM Settings
    1. 5.1  Application-Based Configuration Settings
    2. 5.2  Device Identification Settings
    3. 5.3  BUCK Settings
    4. 5.4  LDO Settings
    5. 5.5  VCCA Settings
    6. 5.6  GPIO Settings
    7. 5.7  Finite State Machine (FSM) Settings
    8. 5.8  Interrupt Settings
    9. 5.9  POWERGOOD Settings
    10. 5.10 Miscellaneous Settings
    11. 5.11 Interface Settings
    12. 5.12 Multi-Device Settings
    13. 5.13 Watchdog Settings
  7. 6Pre-Configurable Finite State Machine (PFSM) Settings
    1. 6.1 Configured States
    2. 6.2 PFSM Triggers
    3. 6.3 Power Sequences
      1. 6.3.1 TO_SAFE_SEVERE and TO_SAFE
      2. 6.3.2 TO_SAFE_ORDERLY and TO_STANDBY
      3. 6.3.3 ACTIVE_TO_WARM
      4. 6.3.4 ESM_SOC_ERROR
      5. 6.3.5 TO_ACTIVE
      6. 6.3.6 TO_RETENTION
  8. 7Application Examples
    1. 7.1 Initialization
    2. 7.2 Moving Between States; ACTIVE and RETENTION
      1. 7.2.1 ACTIVE
      2. 7.2.2 RETENTION
    3. 7.3 Entering and Exiting Standby
    4. 7.4 Entering and Existing LP_STANDBY
    5. 7.5 Runtime Customization
  9. 8References

Entering and Exiting Standby

STANDBY can be entered from the ACTIVE or the RETENTION states. In order to stay in the mission state of STANDBY and not enter the hardware state LP_STANDBY the LP_STANDBY_SEL bit must be cleared.

Similar to the RETENTION state, the STANDBY state turns off all regulators that power the processor. The ACTIVE state is the only destination state available that the STANDBY state returns to.

When the ENABLE pin goes low, the TO_STANDBY sequence is triggered. When the ENABLE pin goes high again, the PMICs return to the ACTIVE state, defined in the STARTUP_DEST bits. The TO_STANDBY sequence is also triggered by the I2C_0 trigger. When triggered from I2C_0 the PMIC can be triggered to return to the ACTIVE states by GPIO4, GPIO10, or and RTC timer or alarm. In this example, I2C_0 trigger is used to enter the STANDBY state and the GPIO4 is used to enter the ACTIVE state.


Write 0x48:0xC3:0x00:0xF7  // LP_STANDBY_SEL=0
Write 0x48:0x7D:0xC0:0x3F  // Mask NSLEEP bits
Write 0x48:0x34:0xC0;0x3F  // Set GPIO4 to WKUP1 (goes to ACTIVE state)
Write 0x48:0x64:0x08:0xF7  // clear interrupt of GPIO4
Write 0x48:0x4F:0x00:0xF7  // unmask interrupt for GPIO4 falling edge
Write 0x48:0x85:0x01:0xFE  // set I2C_0 trigger, trigger TO_STANDBY sequence
After the GPIO4 has gone low and the PMICs have returned to the ACTIVE state
Write 0x48:0x7D:0x00:0x3F  // unmask NSLEEP bits
Write 0x48:0x86:0x03:0xFC  // Set NSLEEPx bits for ACTIVE state
Write 0x48:0x64:0x08:0xF7  // clear interrupt of GPIO4