4.23. WDG Module

4.23.1. Acronyms and Definitions

Abbreviation/Term	Explanation
AUTOSAR	Automotive Open System Architecture
BSW	Basic Software
DET	Default Error Tracer
HW	Hardware
SW	Software
WDG	Watchdog Timer
MCU	Micro Controller Unit
OS	Operating System

4.23.2. Introduction

This document describes the functionality and configuration of the AUTOSAR BSW module Wdg.

Supported AUTOSAR Release	4.3.1
Supported Configuration Variants	Pre-Compile, Post-build
Vendor ID	WDG_VENDOR_ID (44)
Module ID	WDG_MODULE_ID (102)
Supported Platform	AM263Px

The WDG driver depends on some other modules, like DET for error handling, OSEK/AUTOSAR OS for interrupt handling and the Mcu module for system clock settings.

4.23.3. Functional Overview

4.23.3.1. WDG Driver Architecture

The Wdg driver has architecture as shown in below figure from the AUTOSAR spec

The WDG driver provides services for handling the watch dog timer on the microcontroller.

The WDG driver performs two main tasks, which are as follows:

Initialization of WDG
Reset WDG expiration time (trigger)

4.23.3.2. Initialization

The initialization covers the following steps

Set selected watchdog timer expiration time
Set selected trigger timeout
Set selected window size (Digital Windowed Watchdog)
Set selected mode (Fast or slow can be selected and can be switched runtime)

4.23.3.3. States

WDG_IDLE: This is indicating the module is initialized and not busy.
WDG_BUSY: This is indicating the module is busy.

4.23.3.4. Assumptions

None

4.23.3.5. Limitations

Wdg_SetTriggerCondition(0): If “0” is passed as the parameter for Wdg_SetTriggerCondition will result in an immediate stop of the watchdog triggering and an instantaneous watchdog reset of the ECU (irrespective of whether reaction is NMI or reset).

4.23.3.6. Design overview

Will be updated in future release

4.23.4. Hardware Features

4.23.4.1. Hardware Features supported

Setting default mode and timeout during initialization.
Setting window size (Digital Windowed Watchdog).
Enable watchdog timer.
Service watchdog timer.
Mode can be changed at runtime

4.23.4.2. Not supported Features

Off mode not supported

4.23.4.3. Non compliance

4.23.4.3.1. Deviations to requirements (Requirement Traceability)

4.23.4.3.1.1. Deviation of requirements against AUTOSAR specification requirements

Will be updated in next release

4.23.5. Source files

Static source C Files are defined below

📦AM263Px
┣ 📂build
┣ 📂mcal
┃ ┣ 📂Wdg
┃ ┃ ┣ 📂include
┃ ┃ ┃ ┣ 📜Wdg.h : WDG module header file. Needs to be included by higher layers.
┃ ┃ ┣ 📂src
┃ ┃ ┃ ┣ 📜Wdg.c : Main part of the module functionality, implements the AUTOSAR APIs for WDG driver.
┃ ┃ ┣ 📂V0
┃ ┃ ┃ ┗ 📜Wdg_Priv.c : Platform specific internal file.
┃ ┃ ┃ ┣ 📜Wdg_Priv.h : Platform specific internal file.
┃ ┃ ┗ 📜Makefile
┃ 📂mcal_config
┃ 📂mcal_docs
┃ 📜README.txt

Plugin files are defined below in the table.

Plugin Files	Description
Wdg_Cfg.h	Contains the base addresses, Precompile switches, Macros for channels, counters etc.
Wdg_PBcfg.c	Contains all channels Post-Build Configuration parameters
Wdg_Cfg.c	Contains all channels Pre-Compile Configuration parameters

Fig. 4.98 WDG header file include structure

4.23.6. Module requirements

Will be updated in future release

4.23.6.1. Memory Mapping

Memory Mapping Sections	WDG_CODE	WDG_CODE_ISR	WDG_VAR_NO_INIT	WDG_VAR_ZERO_INIT	WDG_PBCFG	WDG_PBCFG_ROOT
WDG_START_SEC_VAR_INIT_UNSPECIFIED(.bss)				x
WDG _STOP_SEC_VAR_INIT_UNSPECIFIED				x
WDG _START_SEC_CODE_APPL(.text)		x
WDG _STOP_SEC_CODE_APPL		x
WDG _START_SEC_VAR_UNSPECIFIED(.data)			x
WDG _STOP_SEC_VAR_UNSPECIFIED			x
WDG _START_SEC_CODE(.text)	x
WDG _STOP_SEC_CODE	x
WDG_START_SEC_PBCFG(.data)					x
WDG_STOP_SEC_PBCFG					x
WDG_START_SEC_PBCFG_ROOT(.const)						x
WDG_STOP_SEC_PBCFG_ROOT						x

4.23.6.2. Scheduling

The Wdg module has no scheduled functions.

4.23.6.3. Error handling

4.23.6.3.1. Development Error Reporting (DET)

The errors reported to DET and DEM are described in the following table

Type of Error	Related Error code	Value (Hex)
API service used in wrong context (e.g. module not initialized).	WDG_E_DRIVER_STATE	0x10
API service called with wrong / inconsistent parameter(s)	WDG_E_PARAM_MODE	0x11
API service called with wrong / inconsistent parameter(s)	WDG_E_PARAM_CONFIG	0x12
The passed timeout value is higher than the max timeout value.	WDG_E_PARAM_TIMEOUT	0x13
API is called with wrong pointer value (e.g. NULL pointer)	WDG_E_PARAM_POINTER	0x14

4.23.6.3.2. Parameter Checking

AUTOSAR requires that API functions check the validity of their parameters. The checks are described in spec and are done as internal parameter checks of the API functions. These checks are for development error reporting and can be en/dis-abled separately. Refer to the configuration chapter where the en/dis-abling of the checks is described. En/dis-abling of single checks is an addition to the AUTOSAR standard which requires to en/dis-able the complete parameter checking via the parameter WDG_DEV_ERROR_DETECT. The following table shows which parameter checks are performed on which services:

Services	Wdg_Init	Wdg_SetMode	Wdg_SetTriggerCondition	Wdg_GetVersionInfo	Wdg_Trigger
WDG_E_DRIVER_STATE		X			X
WDG_E_PARAM_MODE		X
WDG_E_PARAM_CONFIG
WDG_E_PARAM_TIMEOUT			X
WDG_E_PARAM_POINTER	X			X
WDG_E_MODE_FAILED	X
WDG_E_DISABLE_REJECTED	X

4.23.6.3.3. Production Code Error Reporting

By default, production code related errors are reported to the DEM using the service DEM_ReportErrorStatus(). The errors reported to DEM are described in the following table:

Type of Error	Related Error code	Description
Assigned by DEM	WDG_E_MODE_FAILED	This error is raised when setting the watchdog mode fails.
Assigned by DEM	WDG_E_DISABLE_REJECTED	Initialization or watchdog mode switch failed because it would disable the watchdog though this is not allowed in this configuration
Assigned by DEM	WDG_E_HARDWARE_ERROR	This error is raised when register write failure occurs (Hardware Failure)

4.23.7. Used resources

4.23.7.1. Interrupt Handling

Watchdog uses Non maskable interrupt (Interrupt Number 128) and the ISR shall be called when interrupt occurs

Interrupt Number	ISR API Mapped
RTI_WDT0_NMI	WDT_Isr

4.23.8. Integration description

4.23.8.1. Dependent modules

4.23.8.1.1. MCU

The module MCU powers up the microcontroller’s peripherals at startup time and initializes the PLL.

4.23.8.1.2. OS

An operating system can be used for task scheduling, interrupt handling, global suspend and restore of interrupts and creating of the Interrupt Vector Table. The WDG module may use AUTOSAR OS to suspend and restore global interrupts.

4.23.8.1.3. SchM

There are no exclusive areas.

4.23.8.1.4. Critical Sections

There are no critical sections.

4.23.8.1.5. DEM

By default, production code related errors are reported to the DEM using the service DEM_ReportErrorStatus(). Note: Dem Event is enable only if $(Module_Name)DemEventParameterRefs is enabled.

4.23.8.1.6. DET

By default, production code related errors are reported to the DET using the service Det_ReportError(). If development error reporting is enabled (i.e. pre-compile parameter WDG_DEV_ERROR_DETECT== STD_ON). The reported service IDs identify the services which are described in 3.4.

4.23.8.1.7. Callback Notification

The WDG driver does not provide any call back functions.

4.23.8.2. Multi-core support

Not supported

4.23.9. Configuration

4.23.9.1. WdgDemEventParameterRefs

Item
Name	WdgDemEventParameterRefs
Description	Reference to the DemEventParameter which shall be issued when the error “Timeout on blocking API call occurs “ has occurred.
Post-build-variant-multiplicity	false
Multiplicity-Configuration-Class	–
Post-Build Time	VARIANT-POST-BUILD
Origin	Texas Instruments
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Link Time	VARIANT-LINK-TIME
Pre-Compile Time	VARIANT-PRE-COMPILE
Link-Time	VARIANT-LINK-TIME
Pre-Compile-Time	VARIANT-PRE-COMPILE

4.23.9.2. WdgGeneral

All general parameters of the watchdog driver are collected here.

4.23.9.2.1. WdgDevErrorDetect

Item
Name	WdgDevErrorDetect
Description	Compile switch to enable / disable development error detection for this module.
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	true

4.23.9.2.2. WdgDisableAllowed

Item
Name	WdgDisableAllowed
Description	Compile switch to allow / forbid disabling the watchdog driver during runtime.
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	false

4.23.9.2.3. WdgIndex

Item
Name	WdgIndex
Description	Represents the watchdog driver’s ID so that it can be referenced by the watchdog interface.
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	0
Max-value	255
Min-value	0

4.23.9.2.4. WdgInitialTimeout

Item
Name	WdgInitialTimeout
Description	The initial timeout (seconds) for the trigger condition to be initialized during Init function. It shall be not larger than WdgMaxTimeout.
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	1.0
Max-value	65.535
Min-value	0.0

4.23.9.2.5. WdgMaxTimeout

Item
Name	WdgMaxTimeout
Description	The maximum timeout (seconds) to which the watchdog trigger condition can be initialized.
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	65.535
Max-value	65.535
Min-value	0.0

4.23.9.2.6. WdgWindowSize

Item
Name	WdgWindowSize
Description	The Digital Windowed Watchdog window size. Selecting 100% enables standard watchdod (not windowed)
Origin	Texas Instruments
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	WINDOW_SIZE_100_PERCENT
Range	WINDOW_SIZE_3_125_PERCENT WINDOW_SIZE_6_25_PERCENT WINDOW_SIZE_12_5_PERCENT WINDOW_SIZE_25_PERCENT WINDOW_SIZE_50_PERCENT WINDOW_SIZE_100_PERCENT

4.23.9.2.7. WdgRunArea

Item
Name	WdgRunArea
Description	Represents the watchdog driver execution area is either from ROM(Flash) or RAM as required with the particular microcontroller.
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	RAM
Range	RAM ROM

4.23.9.2.8. WdgTriggerLocation

Item
Name	WdgTriggerLocation
Description	Location (memory address) of the watchdog trigger routine.
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	NULL_PTR

4.23.9.2.9. WdgVersionInfoApi

Item
Name	WdgVersionInfoApi
Description	Compile switch to enable / disable the version information API
Origin	AUTOSAR_ECUC
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	true

4.23.9.2.10. WdgRegisterReadbackApi

Item
Name	WdgRegisterReadbackApi
Description	Compile switch to enable / disable the Register Readback API
Origin	Texas Instruments
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	false

4.23.9.2.11. WdgRtiFrequency

Item
Name	WdgRtiFrequency
Description	RTI Clock Frequency (MHz)
Origin	Texas Instruments
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	200
Max-value	200
Min-value	0

4.23.9.2.12. WdgSkipForceReset

Item
Name	WdgSkipForceReset
Description	Compile switch to enable / disable skipping force reset of WDG when 0 timeout is passed in Wdg_SetTriggerCondition
Origin	Texas Instruments
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Default-value	false

4.23.10. Examples

4.23.10.1. Overview

Initializes clock using Mcu_Init()
Configure the interrupts for WDG using WDTApp_interruptConfig()
Default Example program is configured in Non-Maskable Interrupt method (WDT will trigger interrupt when counter becomes zero).
WDT window reaction can be changed to “reset” through configuration (EB Tresos).
Get Watchdog version using Wdg_GetVersionInfo()
Calculate and define the triggerValue and maxServiceInterval
In example, service interval is 25ms and service count is 100. So, every 25ms core will service the WDT for 100 times (25*100 = 2500 ms).
Initialize the timer using Gpt_Init()
Initialize the Watchdog using Wdg_Init()
Start the timer using API Gpt_StartTimer()
Set the trigger condition using Wdg_SetTriggerCondition() along with timeout value (Timeout is defined by subtracting triggerValue with maxServiceInterval)
Then after it will raise an interrupt and interrupt will run (WDT_Isr() function). In ISR function core reset will occurs and start running program again automatically.
On reset, Check the reason for the reset using GetResetReason(). If reset happened due to WDT then “Test Passed”
In Reset window reaction mode, after counter reaches to zero POR(Power ON Reset) happens.

4.23.10.2. Hardware Software Setup and Tools

None

4.23.10.3. Steps to build and run example

WDG example application demonstrates the MCAL WDG driver features, which is referred from folder <MCAL_ROOT>/examples/WDG.
This application can be built from the build folder by giving “gmake –s wdg_app PLATFORM=am263px” command in command prompt.
Once the build is completed we get a binary file, which is loaded in our controller and executed.

4.23.10.4. Example Logs

   WDG_APP: Sample Application - STARTS !!!

   WDG MCAL Version Info
   ---------------------
   Vendor ID           : 44
   Module ID           : 102
   SW Major Version    : 9
   SW Minor Version    : 1
   SW Patch Version    : 0

   ----------------------------------------------------------------------------------
   Starting WDG test  !!!
   ----------------------------------------------------------------------------------
   Service Count 100
   Service Interval 25 milliseconds
   ------------------------------------------
   Trigger Value = 2500 milliseconds
   ------------------------------------------
   Maximum Service Interval 74 milliseconds 
   Initializing channels
   Post-Build variant is being used .
   Reset Reason 2 
   Test Passed!! 
   WDG Stack Usage: 800 bytes
   ------------------------------------------

4.23.10.5. File Structure

📦AM263Px
┣ 📂build
┃ ┣ 📂examples
┃ ┃ ┣ 📂Wdg
┃ ┃ ┃ ┣ 📂soc
┃ ┃ ┃ ┣ 📜WdgApp.c : Contains WDG test example.
┃ ┃ ┃ ┣ 📜WdgApp.h : Contains WDG test example headers.
┃ ┃ ┃ ┣ 📜Makefile
┃ ┣ 📂examples_config
┃ ┃ ┣ 📂Wdg_Demo_Cfg
┃ ┃ ┃ ┣ 📂soc
┃ ┃ ┃ ┃ ┣ 📂am263px
┃ ┃ ┃ ┃ ┃ ┣ 📂r5f0_0
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📂include
┃ ┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Wdg_Cfg.h : Contains the Precompile switches, Macros etc.
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📂src
┃ ┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Wdg_Cfg.c : Contains Pre-Compile Configuration parameters
┃ ┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Wdg_Lcfg.c : Contains linker Configuration parameters
┃ ┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Wdg_PBcfg.c : Contains Post-Build Configuration parameters
┃ 📂mcal_config
┃ 📂mcal_docs
┣ 📜README.txt

4.23.11. FAQ’s

Will be updated in next release

4.23.12. References

AUTOSAR_SWS_WatchdogDriver
Technical Reference Manual