SLVUCR8A September   2023  – March 2024 TPS25751

 

  1.   1
  2.   Read This First
    1.     Notational Conventions
    2.     Glossary
    3.     Related Documents
    4.     Support Resources
    5.     Trademarks
  3. 1Introduction
    1. 1.1 Introduction
      1. 1.1.1 Purpose and Scope
    2. 1.2 PD Controller Host Interface Description
      1. 1.2.1 Overview
      2. 1.2.2 Register and Field Notation
    3. 1.3 Unique Address Interface
      1. 1.3.1 Unique Address Interface Protocol
  4. 2PD Controller Policy Modes
    1. 2.1 Overview
    2. 2.2 Source Policy Mode
    3. 2.3 Sink Policy Mode
  5. 3TPS25751 Registers
  6. 44CC Task Detailed Descriptions
    1. 4.1 CPU Control Tasks
      1. 4.1.1 'Gaid' - Return to Normal Operation
      2. 4.1.2 'GAID' - Cold Reset Request
    2. 4.2 PD Message Tasks
      1. 4.2.1 'SWSk' - PD PR_Swap to Sink
      2. 4.2.2 'SWSr' - PD PR_Swap to Source
      3. 4.2.3 'SWDF' - PD DR_Swap to DFP
      4. 4.2.4 'SWUF' - PD DR_Swap to UFP
      5. 4.2.5 'GSkC' - PD Get Sink Capabilities
      6. 4.2.6 'GSrC' - PD Get Source Capabilities
      7. 4.2.7 'GPPI' - PD Get Port Partner Information
      8. 4.2.8 'SSrC' - PD Send Source Capabilities
      9. 4.2.9 'MBRd' - Message Buffer Read
    3. 4.3 Patch Bundle Update Tasks
      1. 4.3.1 'PBMs' - Start Patch Burst Mode Download Sequence
      2. 4.3.2 'PBMc' - Patch Burst Mode Download Complete
      3. 4.3.3 'PBMe' - End Patch Burst Mode Download Sequence
      4. 4.3.4 'GO2P' - Go to Patch Mode
    4. 4.4 System Tasks
      1. 4.4.1 'DBfg' - Clear Dead Battery Flag
      2. 4.4.2 'I2Cr' - I2C Read Transaction
      3. 4.4.3 'I2Cw' - I2C Write Transaction
  7. 5User Reference
    1. 5.1 PD Controller Application Customization
    2. 5.2 Loading a Patch Bundle
    3. 5.3 GPIO Events
    4. 5.4 AUTO_NEGOTIATE_SINK Register
      1. 5.4.1 AUTO_NEGOTIATE_SINK Usage Example 1
      2. 5.4.2 AUTO_NEGOTIATE_SINK Usage Example 2
      3. 5.4.3 AUTO_NEGOTIATE_SINK Usage Example 3
      4. 5.4.4 AUTO_NEGOTIATE_SINK Usage Example 4
  8. 6Revision History

4.2.4 'SWUF' - PD DR_Swap to UFP

Table 4-6 'SWUF' - PD DR_Swap to UFP
DescriptionThe 'SWUF' Task instructs PD Controller to attempt to become a UFPthrough DR_Swap at the first opportunity while maintaining policy enginecompliance. If there are any active Alternate Modes as a DFP PD Controller willexit those Modes first before attempting the DR_Swap.
INPUT DATAXNone
OUTPUT DATAXByte 1: Standard Task Return Code.
Task CompletionThe 'SWUF' Task completes either when the DR_Swap is finished or it is otherwise determined to not be possible or fails. The Task can continue to run because of Wait messages being sent by the UFP. The 'SWUF' Task shall be considered rejected if:
  • The DFP indicated through Source or Sink Capabilities that it does not support Data Role Swap.
  • The DR_Swap is Rejected.
The 'SWUF' Task shall be considered successful if:
  • PD Controller is already in the UFP data role.
  • The DR_Swap is Accepted and completes normally.
Side EffectsWhen the 'SWDF' Task completes successfully PD Controller will have transitioned to the UFP data role, which impacts other registers. If the DR_Swap fails after the Accept is sent then Soft and/or Hard Resets are likely to occur per PD spec requirements.
Additional InformationNone