SNLS757B June   2024  – November 2024 TUSB2E221

PRODMIX  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Variants
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Timing Requirements
    8. 6.8 Typical Characteristics
  8. 7 Parametric Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 USB 2.0
      2. 8.3.2 eUSB2
      3. 8.3.3 Cross MUX
    4. 8.4 Device Functional Modes
      1. 8.4.1  Repeater Mode
      2. 8.4.2  Power-Down Mode
      3. 8.4.3  UART Mode
      4. 8.4.4  Auto-Resume ECR
      5. 8.4.5  L2 State Interrupt Modes
      6. 8.4.6  Attach Detect Interrupt Mode
      7. 8.4.7  GPIO Mode
        1. 8.4.7.1 EQ0 as GPIO0
        2. 8.4.7.2 EQ1 as GPIO1
        3. 8.4.7.3 EQ2/INT as GPIO2
      8. 8.4.8  CROSS
      9. 8.4.9  USB 2.0 High-Speed HOST Disconnect Detection
      10. 8.4.10 Frame Based Low Power Mode
    5. 8.5 Programming
      1. 8.5.1 I2C Target Interface
      2. 8.5.2 Register Access Protocol (RAP)
  10. 9 Register Map
    1. 9.1 TUSB2E221 Registers
  11. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application: Dual Port System
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 eUSB PHY Settings Recommendation
      3. 10.2.3 Application Curve
    3. 10.3 Power Supply Recommendations
      1. 10.3.1 Power-Up Reset
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Example Layout
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

8.4.3 UART Mode

In I2C mode GPIO0 defaults as an enable control for Carkit UART mode. GPIO0 is an active low signal to enable Carkit UART mode. GPIO0 can be controlled through APU or SoC. When APU or SoC is not powered on or the firmware has not been loaded, GPIO0 is low. When GPIO0 is low, the UART mode allows access to the APU or SoC debug interface through the USB port.

Default Carkit UART direction is DP → eDP (RX) and eDN → DN (TX).

On the rising edge of GPIO0, followed by TMODE_SWITCH, the TUSB2E221 is enabled and enters the default state, ready to accept eUSB2 port reset, configuration or RAP. The repeater mode is configured as host or peripheral depending on the eUSB2-defined configuration received from eUSBr and acknowledged by the repeater.

UART mode enable is controlled through GPIO0 after power up. This can be changed through UART_use_bit1_Px bit in UART-PORTx register, so UART mode enable can be controlled through a register instead of GPIO0.