Infineon STM Interrupt 1 User manual

AURIX™ TC2xx Microcontroller Training
V1.0.0
STM_Interrupt_1
Interrupt generation via STM trigger
Please read the Important Notice and Warnings at the end of this document

Scope of work
The STM is configured to trigger an interrupt every 500 ms. The
interrupt toggles an LED.
The System Timer (STM) module counts up to a configured compare value,
when it reaches the specific value, it triggers an interrupt and resets its
counter value. The value is set to trigger the interrupt every 500 ms; at each
interrupt an LED is toggled.
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Introduction
›The System Timer (STM) is a free running 64-bit counter that can be used
for timing applications requiring both high precision and long period.
›Among other features, the STM has the capability to generate interrupts
when its count reaches a predefined compare value.
›The comparison is flexible in terms of bit sets.
Any of the 64 bits of the STM can be selected for comparison.
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Hardware setup
This code example has been
developed for the board
KIT_AURIX_TC297_TFT_BC-Step.
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Implementation
Configure and control the LED
The LED is toggled by controlling the port pin to which it is connected using functions
from the iLLD header IfxPort.h.
Inside the function initPeripherals(), the port pin is configured to push-pull output
mode using the function IfxPort_setPinMode().
During program execution, inside the interrupt service routine isrSTM(), the LED is
switched on and off using the function IfxPort_setPinState().
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Implementation
Configure the STM
Configuration of the STM is done inside the function initSTM() by initializing an
instance of the IfxStm_CompareConfig structure with default values through the
function IfxStm_initCompareConfig().
Then, the following parameters are modified:
›ticks –the total amount of ticks to count before the interrupt generation.
›triggerPriority –priority of the interrupt generated by the STM on compare match.
It can be a value from 0 to 255, with 0 meaning interrupt is disabled and 255 is the
highest priority.
›typeOfService –to define which service provider is responsible for handling the
interrupt. This can be any of the available CPUs or the DMA.
The above functions can be found in the iLLD header IfxStm.h.
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Implementation
Configure the Interrupt Service Routine
The function implementing the ISR (isrSTM()) needs to be assigned a priority and a
core responsible for its execution.
This is done with the macro IFX_INTERRUPT(isr, vectabNum, priority).
When triggered, the ISR:
›Instructs the STM to raise the next interrupt after a certain amount of time by
updating its compare register with the function IfxStm_increaseCompare().
›Toggles the LED by changing the state of the port pin using the function
IfxPort_setPinState().
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Run and Test
After code compilation and flashing the device, observe the LED D107 (1),
which should be blinking.
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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
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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.
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Document reference
STM_Interrupt_1
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