SLVUBY7A October   2020  – October 2022 DRA821U , LP8764-Q1 , TPS6594-Q1

 

  1.   User's Guide for Powering DRA821 with TPS6594-Q1 and LP8764-Q1
  2.   Trademarks
  3. 1Introduction
  4. 2Device Versions
  5. 3Processor Connections
  6. 4Supporting Functional Safety Systems
    1. 4.1 Achieving ASIL-B System Requirements
    2. 4.2 Achieving up to ASIL-D System Requirements
  7. 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
  8. 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
      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 PWR_SOC_ERROR
      6. 6.3.6 MCU_TO_WARM
      7. 6.3.7 TO_MCU
      8. 6.3.8 TO_ACTIVE
      9. 6.3.9 TO_RETENTION
  9. 7Application Examples
    1. 7.1 Moving Between States: ACTIVE, MCU, and RETENTION
      1. 7.1.1 ACTIVE
      2. 7.1.2 MCU ONLY
      3. 7.1.3 RETENTION
    2. 7.2 Entering and Exiting Standby
    3. 7.3 Entering and Existing LP_STANDBY
    4. 7.4 GPIO8 and Watchdog
  10. 8Additional Resources
  11. 9Revision History

4.2 Achieving up to ASIL-D System Requirements

For ASIL-C or ASIL-D systems, there are additional features to the ones described in Section 4.1 that can be utilized. These features include:

  • PMIC current monitoring on all output power rails
  • Isolation of the MCU and Main power domains of the processor
  • SoC reset

The current monitoring is enabled by default for all BUCKs and LDOs for the TPS6594-Q1 and LP8764-Q1 devices. Additionally, Figure 3-1 shows that the MCU domain of the processor is powered by different power resources of the PMICs than the main power domain of the processor. SoC reset functionality is supported through the connection of GPIO_11 on TPS6594-Q1, configured as nRSTOUT_SoC, to the PORz pin of the processor.

Note: Residual voltage checking is available on the PMICs to prevent startup when output rails are not discharged below 100 mV as may happen under a fault condition. However, this feature is not enabled in the NVM settings of this PDN to support repetitive power cycling during system software development.