Infineon ERU Interrupt 1 User manual

AURIX™ TC2xx Microcontroller Training
V1.0.0
ERU_Interrupt_1
External interrupt generation
Please read the Important Notice and Warnings at the end of this document

Scope of work
The ERU is used to generate an interrupt on each rising and falling
edge at an input pin.
The code example uses the External Request Unit (ERU) to generate an
interrupt for each falling and rising edge at the input pin P02.0. The falling
and rising edges are generated with pin P02.1. If an Interrupt occurs, an LED
will be toggled.
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Introduction
›The External Request Unit (ERU) is a versatile event and pattern
detection unit.
›Its main task is the generation of interrupts based on selectable
trigger events at different inputs, e.g. to generate external interrupt
requests if an edge occurs at an input pin.
›The detected events can also be used by other modules to trigger or to
gate module specific actions.
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Hardware setup
This code example has been developed
for the board
KIT_AURIX_TC297_TFT_BC-Step.
The two pins P02.0 and P02.1 have to be
connected to each other.
Input Output
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Implementation
›To generate an interrupt via a falling and rising edges on an input pin a few
configuration steps are required:
–Initialize external request pin (IfxScuEru_initReqPin())
–Select which edge should trigger the interrupt
(IfxScuEru_enableRisingEdgeDetection() and/or
IfxScuEru_enableFallingEdgeDetection())
–Enable generation of trigger events with the function
IfxScuEru_enableTriggerPulse()
–Choose the output channel by selecting the Output Gating Unit (OGUz) and the
trigger pulse output (TRxz)
–An event from the Event Trigger Logic (ETL0) triggers the OGU0 (signal
TRx0). The function IfxScuEru_connectTrigger() determines the output
channel for the trigger event
–Select the condition to generate an interrupt with the function
IfxScuEru_setInterruptGatingPattern()
–Configure and enable the service request with the functions IfxSrc_init() and
IfxSrc_enable()
›The functions above are provided by the iLLD headers IfxScuEru.h and IfxSrc.h.
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Implementation
›The below figures from the AURIX™
TC29x B-Step User’s Manual illustrate
the configuration steps that were
followed in this example.
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Implementation
The Interrupt Service Routine (ISR)
Blinking an LED is implemented inside an ISR triggered by the ERU which generates
interrupt requests according to its configuration.
The method implementing the ISR needs to be assigned a priority and a CPU core
responsible for its execution. This is done with the macro IFX_INTERRUPT(isr,
vectabNum, priority).
When triggered, the ISR blinks the LED by toggling the state of the connected pin
using the function IfxPort_setPinState().
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Run and Test
After code compilation and flashing the
device, perform the following steps:
1. Connect the two pins P02.0 and
P02.1 to each other.
P02.1 is used to generate the
falling and rising edges by
toggling the state from high to
low. P02.0 is the input of the
ERU which generates the
interrupts on falling and rising
edges.
2. Toggle the P02.1 pin state via
the value of the variable
LEDstate of the structure
g_ERUconfig with the
debugger.
3. Check LED D107 (1) is
changing state when the
variable is modified.
1
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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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ERU_Interrupt_1
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