Watchdog Timer standalone driver

Introduction

The watchdog timer can be used to prevent system lockup; for example, when software becomes trapped in a deadlock.
In normal operation, the user restarts the watchdog at regular intervals before the timer counts down to zero.
In cases where the timer does reach zero and the watchdog is enabled, one or a combination of the following signals is
generated: a system reset, an interrupt, or an external signal. The watchdog timeout period and the duration of any output signals are programmable.
For more information, please refer Chapter 14: Timers and clocks in Zynqmp Trm which includes links to the official documentation and resource utilization.

Driver Sources

The source code for the driver is included with the Vitis Unified Software Platform installation, as well as being available in the Xilinx Github repository. 

Driver NamePath in vitisPath in Git Hub
wdtps

<Vitis Install Directory>/data/embedded/XilinxProcessorIPLib/drivers/wdtps

https://github.com/Xilinx/embeddedsw/blob/master/XilinxProcessorIPLib/drivers/wdtps

Note: To view the sources for a particular release, use the rel-version tag in github.  For example, for the 2020.1 release, the proper version of the code is: https://github.com/Xilinx/embeddedsw/blob/master/XilinxProcessorIPLib/drivers/wdtps

The driver source code is organized into different folders. The table below shows the wdtps driver source organization.

DirectoryDescription
srcDriver source files
examplesExample applications that show how to use the driver features
docProvides the API and data structure details
dataDriver .tcl and .mdd file

Driver Implementation

For a full list of features supported by this IP, please refer Chapter 14: Timers and clocks in Zynqmp Trm

Features

Controller Features supported

  • Configurable timeout interval in seconds.
  • Reset on timeout can be selected.

Driver Supported Features


The Axi watchdog timer Standalone driver supports the below things.
All Controller Features supported.

Known Issues and Limitations

  • None.

Example Applications

Refer to the driver examples directory for various example applications that exercise the different features of the driver. Each application is linked in the table below. The following sections describe the usage and expected output of the various applications.  These example applications can be imported into the Vitis IDE from the Board Support Package  settings tab.

Links to Examples

Examples Path:

https://github.com/Xilinx/embeddedsw/blob/master/XilinxProcessorIPLib/drivers/wdtps/examples

Test nameExample sourceDescription
basic test

xwdtps_selftest_example.c

This example does a minimal test on the System Watchdog Timer device.
Polled

xwdtps_polled_example.c

This example tests the functioning of the System WatchDog Timer driver in the polled mode
Interruptxwdtps_intr_example.cThis example tests the functioning of the System WatchDog Timer driver in the Interrupt mode

Example Application Usage

xwdtps_selftest_example.c

WDT SelfTest Example Test
Successfully ran WDT SelfTest Example Test

xwdtps_polled_example.c

WDT Polled Mode Example Test
Successfully ran WDT Polled Mode Example Test

xwdtps_intr_example.c

WDT Interrupt Example Test
Successfully ran WDT Interrupt Example Test

Example Design Architecture

NA


ChangeLog

2021.1

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2021.1/doc/ChangeLog#L363

2020.2

https://github.com/Xilinx/embeddedsw/blob/release-2020.2/doc/ChangeLog#L248

2020.1

https://github.com/Xilinx/embeddedsw/blob/release-2020.1/doc/ChangeLog#L560

2019.2

https://github.com/Xilinx/embeddedsw/blob/release-2019.2/doc/ChangeLog#L101

2019.1

None

2018.3

https://github.com/Xilinx/embeddedsw/blob/release-2018.3/doc/ChangeLog#L430

Related Links