Infineon ASCLIN SPI Master 1 User manual

AURIX™ TC2xx Microcontroller Training
V1.0.0
ASCLIN_SPI_Master_1
SPI master communication via ASCLIN module
Please read the Important Notice and Warnings at the end of this document

Scope of work
An ASCLIN module configured as SPI master sends a two bytes
message.
The two bytes message is sent through MTSR (MOSI) port pin P15.4 in
loopback mode. This signal can be visualized on the oscilloscope screen.
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2019-10-17 Copyright © Infineon Technologies AG 2019. All rights reserved.

Introduction
›The Asynchronous/Synchronous Interface (ASCLIN) module provides
synchronous serial communication like SPI with external devices, using
data-in and data-out signals only.
›The ASCLIN module in SPI configuration can support master mode only
with four-wire or three-wire (without slave select output signal) and up to
16-bit data width.
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This code example has been developed for the
board KIT_AURIX_TC297_TFT_BC-Step.
The port pin P15.4 (SPI-MTSR) should be
connected to the port pin P15.5 (SPI-MRST) in
order to form an internal loopback.
Those pins can also be connected to an
oscilloscope probe for observing the SPI
signal.
Hardware setup
Ground
MRST MTSR
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Implementation
Configuration of the ASCLIN module:
Configuration of the ASCLIN module for SPI communication is done in the setup phase by
initializing an instance of the IfxAsclin_Spi_Config structure with the following
parameters:
›baudrate –structure to set the actual communication speed in bit/s
›interrupt –structure to set:
–transmit and receive interrupt priorities (txPriority, rxPriority)
–typeOfService –defines which service provider is responsible for handling the
interrupt, which can be any of the available CPUs, or the DMA
›pins –structure to set which GPIO port pins are used for the communication
›rxBuffer, rxBufferSize,txBuffer, txBufferSize –to configure the buffers that will hold
the incoming/outgoing data
The function IfxAsclin_Spi_initModuleConfig() fills the configuration structure with
default values and IfxAsclin_Spi_initModule() initializes the module with the user
configuration.
All the above functions can be found in the iLLD header IfxAsclin_Spi.h.
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Implementation
The SPI message exchange function:
›The data-out (MTSR/MOSI) is connected via internal loopback to the data-in
(MRST/MISO).
›The two bytes message is sent via the function exchange_ASCLIN_SPI_message()
which is called once after initialization of the ASCLIN module.
›The two bytes message is sent from the g_spiTxBuffer to the g_spiRxBuffer using
the function IfxAsclin_Spi_exchange() from the IfxAsclin_Spi.h header file.
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Run and Test
After code compilation and flashing the device, perform the following steps:
›Connect the oscilloscope probe to the MTSR pin (P15.4)
›Reset and run the program by pressing the PORST push button
›Check the oscilloscope for the SPI signal:
Start Stop
Start
Stop
Byte 1 Byte 2
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Run and Test
An additional test without using an oscilloscope can be performed with the
debugger.
›Before transmission, the buffer g_spiTxBuffer is filled with a two bytes
message and the buffer g_spiRxBuffer is empty.
›After transmission, both buffers should hold the same message:
–By using the debugger, you can watch the content of both buffers
before and after transmission by setting a breakpoint to
exchange_ASCLIN_SPI_message().
–When reaching this breakpoint, check the content of both buffers (it
should be different).
–After stepping over this function, the content of the buffers must be
equal.
Note: The code should run for a few seconds in order to grant enough time
for the transmission to be done.
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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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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.
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Document reference
ASCLIN_SPI_Master_1
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