WDT Example

Source code path: example/rt_device/wdt/wdt

Supported Platforms

• sf32lb52-lcd_n16r8

• sf32lb58-lcd_n16r64n4

Overview

This example demonstrates WDT usage based on rt-device (using rt-thread), including:

• WDT on/off.

• WDT feeding.

• WDT timeout response.

Tip

This example is based on HCPU, using IWDT and WDT1.

Example Usage

Hardware Requirements

Before running this example, you need to prepare a development board supported by this example

menuconfig Configuration

1. BSP enable WDT (automatically configures RT_USING_WDT):

2. Configure WDT timeout time (WDT_TIMEOUT):

Compilation and Programming

Switch to example project directory and run scons command to execute compilation:

scons --board=eh-lb525 -j32

Run build_sf32lb52-lcd_n16r8_hcpu\uart_download.bat, select port as prompted to download:

$ ./uart_download.bat

     Uart Download

please input the serial port num:5

For detailed steps on compilation and downloading, please refer to Getting Started Guide related introduction.

Expected Results of Example

After example startup, serial port outputs as follows:

1. WDT off then on:

11-01 11:05:24:772    WDT Example.
11-01 11:05:24:813    WDT off.
11-01 11:05:24:816    WDT on.

Tip

When using rt-thread, WDT initialization configuration and enable (rt_hw_watchdog_init) are already completed by default in startup process, no need to call initialization configuration and enable separately.

2. Cancel feeding in idle thread:

11-01 11:05:24:820    Unregister idle hook.

Tip

rt_hw_watchdog_init registers idle hook for feeding. Cancel here to demonstrate manual feeding.

3. Feeding (every 5 seconds):

11-01 11:05:29:709    watchdog feeding.
11-01 11:05:34:699    watchdog feeding.
11-01 11:05:39:668    watchdog feeding.
11-01 11:05:44:660    watchdog feeding.
11-01 11:05:49:629    watchdog feeding.
11-01 11:05:54:600    watchdog feeding.
11-01 11:05:59:594    watchdog feeding.
11-01 11:06:04:575    watchdog feeding.
11-01 11:06:09:558    watchdog feeding.
11-01 11:06:14:553    watchdog feeding.

3. After stopping feeding, WDT1 timeout (WDT_TIMEOUT, configured in menuconfig), generating interrupt. In interrupt (WDT_IRQHandler) WDT1/WDT2 will be disabled, IWDT refreshed, IWDT timeout time updated (WDT_TIMEOUT):

11-01 11:06:14:557    Stop watchdog feeding.
11-01 11:06:51:813    WDT1 timeout occurs.
11-01 11:06:51:817    WDT reconfig:
11-01 11:06:51:821      WDT1 and WDT2 has been stopped.
11-01 11:06:51:825      IWDT refreshed and set timeout time to WDT_TIMEOUT.

Tip

Provides overridable function: wdt_store_exception_information, called by WDT_IRQHandler. Can be used to save scene, reboot system, etc.

4. IWDT timeout resets system:

11-01 11:07:35:237    SFBL
11-01 11:07:37:445    Serial:c2,Chip:4,Package:3,Rev:2  Reason:00000000

Exception Diagnosis

1. Confirm WDT configuration status (enable status, count configuration, working mode) through WDT registers:

Reference Documents

Update Log

Version	Date	Release Notes
0.0.1	10/2024	Initial version