Infineon SCU Reset Detection 1 User manual

AURIX™ TC2xx Microcontroller Training
V1.0.0
SCU_Reset_Detection_1
Detection of reset type
Please read the Important Notice and Warnings at the end of this document

Scope of work
This example shows how to detect the source of the last reset (power-
on reset, watchdog reset, etc.)
The AURIX™ TC2xx devices can be reset by various reset sources. The
application software is able to determine the source of the last reset based
on a routine that evaluates the related reset special function register.
2
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

Introduction
›Resets can be configured and determined in the Reset Control Unit
(RCU), belonging to the System Control Unit (SCU).
›There are various reset triggers such as SupplyMonitor, EVRs, PORST,
ESRx, JTAG.
›Consequently, different reset types can be derived, such as Cold-/Warm-
Power-On Reset, System Reset, Application Reset, Debug Reset, Module
Reset.
3
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

Hardware setup
This code example has been
developed for the board
KIT_AURIX_TC297_TFT_BC-Step.
4
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

Implementation
startScuResetDetection()
›This function executes the evaluateReset() function, which provides information
about the last occurred reset. The returned value is a data structure comprising
elements such as resetType and resetTrigger.
›The resetType specifies the type of the last reset (e.g. a Cold Power-On Reset,
System Reset, Application Reset or Warm Power-On Reset).
›The resetTrigger specifies the source of the last reset. For instance, the source
can be a Power-On Reset (pressing PORST-Button), a SW triggered reset or a
reset triggered by debugger or any voltage supervision monitor.
›Furthermore, the function evaluateReset() clears the Cold Power-On sticky bits
using the function clearColdPowerOnResetBits(). Those bits are not cleared
automatically and must be explicitly cleared by the application.
›The local variable swReset can be used to specify the type of SW-Reset initiated
by the function triggerSWReset().
5
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

Implementation
evaluateReset()
›The function evaluateReset() evaluates both the SCU.RCU.RSTSTAT and
SCU.RCU.RSTCON registers.
›The SCU.RCU.RSTSTAT register is evaluated with regard to which reset bits are
set, respectively, cleared. Firstly, the warm reset status bits comprising ESRx,
SMU,SW, STMx and CBx are evaluated. Secondly, the cold reset status bits
comprising EVR13, EVR33,SWD and STBYR are evaluated if none of the warm
reset status bits are set. Finally, the PORST bit is evaluated.
›The SCU.RCU.RSTCON is evaluated to determine the type of reset, specified for
the warm reset status bits, except debugger related reset sources.
triggerSWReset()
›This function was developed only for testing purposes. Based on the local variable
swReset, it triggers either a SW Application Reset or a SW System Reset.
6
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

Run and Test
After code compilation and flashing the device, perform the following steps:
1. Run the code
2. Suspend the code execution
3. Watch the local structure variable lastReset (the elements lastReset.resetType and
lastReset.resetTrigger)
4. Check whether the lastReset.resetType is set to 'application' reset and whether the
lastReset.resetTrigger is set to 'cb3'.
5. Press button 'PORST'
6. Perform steps 1. through 3.
7. Check whether the lastReset.resetType is set to 'warmpoweron' reset and whether
the lastReset.resetTrigger is set to 'porst'.
7
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

Run and Test
8. Set the local variable swReset to '1'
9. Perform steps 1. through 3.
10. Check whether the lastReset.resetType is set to 'application' reset and whether the
lastReset.resetTrigger is set to 'sw'.
11. Set the local variable swReset to '2'
12. Perform steps 1. through 3.
13. Check whether the lastReset.resetType is set to 'system' reset and whether the
lastReset.resetTrigger is set to 'sw'.
8
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

References
›More code examples can be found on the GIT repository:
›https://github.com/Infineon/AURIX_code_examples
›For additional trainings, visit our webpage:
›https://www.infineon.com/aurix-expert-training
›AURIX™ Development Studio is available online:
›https://www.infineon.com/aurixdevelopmentstudio
›Use the „Import...“ function to get access to more code examples.
›For questions and support, use the AURIX™ Forum:
›https://www.infineonforums.com/forums/13-Aurix-Forum
9
2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

IMPORTANT NOTICE
The information given in this document shall in no
event be regarded as a guarantee of conditions or
characteristics (“Beschaffenheitsgarantie”).
With respect to any examples, hints or any typical
values stated herein and/or any information
regarding the application of the product, Infineon
Technologies hereby disclaims any and all
warranties and liabilities of any kind, including
without limitation warranties of non-infringement
of intellectual property rights of any third party.
In addition, any information given in this
document is subject to customer’s compliance
with its obligations stated in this document and
any applicable legal requirements, norms and
standards concerning customer’s products and
any use of the product of Infineon Technologies in
customer’s applications.
The data contained in this document is exclusively
intended for technically trained staff. It is the
responsibility of customer’s technical
departments to evaluate the suitability of the
product for the intended application and the
completeness of the product information given in
this document with respect to such application.
For further information on the product,
technology, delivery terms and conditions and
prices please contact your nearest Infineon
Technologies office (www.infineon.com).
WARNINGS
Due to technical requirements products may
contain dangerous substances. For information
on the types in question please contact your
nearest Infineon Technologies office.
Except as otherwise explicitly approved by
Infineon Technologies in a written document
signed by authorized representatives of Infineon
Technologies, Infineon Technologies’ products
may not be used in any applications where a
failure of the product or any consequences of the
use thereof can reasonably be expected to result
in personal injury.
Edition 2019-10
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2019 Infineon Technologies AG.
All Rights Reserved.
Do you have a question about this
document?
Email: [e-mail]
Document reference
SCU_Reset_Detection_1
Trademarks
All referenced product or service names and trademarks are the property of their respective owners.