AXI Watchdog Timer standalone driver


Introduction


This page gives an overview of Axi Watchdog timer driver /Window watchdog timer which is available as part of the Xilinx Vivado and SDK distribution.

The Xilinx® LogiCORE? IP AXI4-Lite Timebase Watchdog Timer (WDT) is a 32-bit peripheral that provides a 32-bit free-running
timebase and watchdog timer.
For more information, please refer  AXI_Timebase_Wdt_Doc
Same Driver supports for  Versal platform , on versal supports Generic watchdog and window watchdog features.
For more information, please refer Chapter 59: System Watchdog Timer Versal 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. 

DriverPath in vitisPath in Git Hub
wdttb<Vitis Install Directory>/data/embedded/XilinxProcessorIPLib/drivers/wdttbhttps://github.com/Xilinx/embeddedsw/tree/master/XilinxProcessorIPLib/drivers/wdttb

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/tree/master/XilinxProcessorIPLib/drivers/wdttb

The driver source code is organized into different folders. The table below shows the wdttb 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 AXI_Timebase_Wdt_Doc

For a full list of features supported by this IP, please refer 59: System Watchdog Timer Versal Trm

Features

Controller Features supported

• Connects as a 32-bit slave on a AXI4-Lite interface
• Watchdog timer with selectable timeout period and interrupt
• Configurable WDT enable: enable-once or enable-repeatedly
• One 32-bit free-running timebase counter with rollover interrupt-dual control register

Driver Supported Features

The Axi watchdog timer Standalone driver support the below things.
All Controller Features supported.
WWDT Driver support:
  • Supports Generic Watch dog timer and polled and interrupt mode window watch dog feature.
  • Q&A mode not implemented.

Known Issues and Limitataions

  • 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/tree/master/XilinxProcessorIPLib/drivers/wdttb/examples

Test NameExample sourceDescription

xwdttb_low_level_example.c

















Test NameExample sourceDescription

xwdttb_low_level_example.cThis example checks for Watchdog timer reset condition in two timer expiry state

xwdttb_selftest_example.cThis example does a minimal test on the watchdog timer timebase device and drive

xwdttb_example.cThis example tests the functioning of the TimeBase WatchDog Timer module in the polled mode

xwdttb_intr_example.cThis example tests the functioning of the TimeBase WatchDog Timer module in the interrupt mode

xwdttb_winwdt_example.cThis exampletests the functioning of the TimeBase WatchDog Timer module with window feature in the polled mode.

xwdttb_winwdt_intr_example.cThis example tests the functioning of the TimeBase WatchDog Timer module with window feature in the interrupt mode.

xwdttb_gwdt_selftest_example.cThis example does a minimal test on Generic watchdog timer device

xwdttb_gwdt_example.cThis example tests the functioning of the Generic watch dog Timer Feature in Polled mode

xwdttb_gwdt_intr_example.cThis example tests the functioning of the Generic watch dog Timer Feature in interrupt mode

Example Application Usage

WDTTB examples


Expected Output

xwdttb_low_level_example.c
OUTPUT:
Successfully ran WDTTB low level example.

xwdttb_selftest_example.c 
OUTPUT:
Successfully ran WDTTB self test example.

xwdttb_example.c
OUTPUT:
Restart kick 1
.........................
Restart kick 2
.........................
Successfully ran WDTTB example

xwdttb_intr_example.c
OUTPUT:
Successfully ran Window WDT interrupt example.

xwdttb_winwdt_example.c
OUTPUT:
Restart kick 1
.........................
Restart kick 2
.........................
Successfully ran Window WDT example.

xwdttb_winwdt_intr_example.c
OUTPUT:
Successfully ran Window WDT interrupt example.

xwdttb_gwdt_selftest_example.c
OUTPUT:
Successfully ran GWDT self test example

xwdttb_gwdt_example.c
OUTPUT:
Self test completed
.................................................................................................................................
 Refresh kick1
................................................................................................................
 Refresh kick2
................................................................................................................
 Refresh kick3
................................................................................................................................................................................................................................................
Generic watchdog second window expired

xwdttb_gwdt_intr_example.c
OUTPUT:
Successfully ran GWDT interrupt example


ChangeLog

2021.2

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2021.2/doc/ChangeLog#L922


2019.2

https://github.com/Xilinx/embeddedsw/blob/release-2019.2/doc/ChangeLog#L104

2019.1

https://github.com/Xilinx/embeddedsw/blob/release-2019.1/doc/ChangeLog#L178

Related Links