TIDUEY9 April   2021

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 LP8770
        1. 2.3.1.1 Safety Features
          1. 2.3.1.1.1 Window Watchdog
          2. 2.3.1.1.2 Voltage Monitoring
      2. 2.3.2 AWR1843/xWR6843 mmWave Sensor Solution
    4. 2.4 System Design
      1. 2.4.1 Hardware Block Diagram
      2. 2.4.2 Software Components
        1. 2.4.2.1 Secondary Bootloader (SBL)
        2. 2.4.2.2 mmWaveLink APIs
        3. 2.4.2.3 mmWave Safety Diagnostic Library (SDL)
        4. 2.4.2.4 mmWave SDK Software Block Diagram
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  10. 5About the Author
2.3.1.1.1 Window Watchdog

WDI is the watchdog function input pin and WD_RESET is the reset output. WDI pin needs to be pulsed within a certain timing window to avoid watchdog expiration. Minimum pulse width is 100 μs. Watchdog expiration always causes a reset pulse at WD_RESET output, otherwise device behavior after watchdog expiration is programmable.

Long open, close and open window periods are independently programmable. When long open or open window expires before WDI input is received, watchdog enters WD Reset state. Also when WDI is received during close window, watchdog enters WD Reset. Long open period can be extended by a I2C write to WD_CTRL_1 or WD_CTRL_2 register.