Timers Drivers

Supported Drivers

• Timer Drivers
  • Enabling the Timer Support and Example in menuconfing
  • Timer Example
  • Application Level Interface
• Oneshot Timer Drivers
  • Background
  • Oneshot Drivers API
  • ClockCount
• PWM Drivers
  • Application Level Interface
    • Application Example
  • Configuration
• Watchdog Timer Drivers
  • Enabling the Watchdog Support and Example in menuconfing
  • Watchdog Timer Example
  • Application Level Interface
  • Enable Built in System Monitoring to reset the watchdog
• RTC Drivers
• Capture
  • Usage
    • Supported ioctl Commands
    • Configuration
    • Example
    • Notes

The NuttX timing subsystem consists of four layers:

• 1 Hardware Timer Drivers: Includes implementations of various hardware

  timer drivers.

• 2 Timer Driver Abstraction: Such as Oneshot and Timer, which provide

  oneshot/periodical timer hardware abstraction.

• 3 OS Timer Interfaces: Arch_Timer(up_timer_*) and Arch_Alarm(up_alarm_*),

  offering relative timer (trigger an event with a certain delay) and absolute timer (trigger an event at a certain time) interfaces.

• 4 OS Timer Abstraction: The wdog timer manages software timers

  and provides a unified timer API to upper layers.

The Timer Driver Abstraction is not mandatory. If the driver is simple enough (e.g.,just providing a periodic tick), the OS Timer interfaces Arch_Timer can be implemented directly, bypassing the timer driver abstraction layer.

The design purpose of the Timer Driver Abstraction is to simplify driver implementation, improve performance, and enhance the reusability of driver code.