4.11. CDD UART Module

4.11.1. Acronyms and Definitions

Abbreviation/Term	Explanation
AUTOSAR	Automotive Open System Architecture
BSW	Basic Software
DET	Default Error Tracer
CDD	Complex Device Driver
DMA	Direct Memory Access
ISR	Interrupt Service Routine
INT	Interrupt
HW	Hardware
SW	Software
MCU	Micro Controller Unit
OS	Operating System
API	Application Programming Interface
UART	Universal Asynchronous Receiver Transmitter

4.11.2. Introduction

This document describes the functionality and configuration of the Cdd_Uart module.

Supported AUTOSAR Release	4.3.1
Supported Configuration Variants	Pre-Compile, Post-Build
Vendor ID	UART_VENDOR_ID (44)
Module ID	UART_MODULE_ID (255)
Supported Platform	AM263Px

The UART complex device driver provides data read and write transfer using the module unit channels in the device board.

4.11.3. Functional Overview

The driver is configurable for parameters such as baud rate, word length, parity, stop bits, IO mode, clock frequency, transmission and reception buffer threshold, and operating mode. Depending upon the IO Mode selected, the driver allows for both synchronous as well as asynchronous mode of data transfer.

The UART Driver provides services for reading and writing to/from

1. UART Channels

2. UART Ports / Serial Device

4.11.3.1. Driver Architecture

The UART driver has architecture as shown in below figure from the AM263 Technical Reference Manual

Fig. 4.52 UART interface

UART comes under the Complex Driver Design section under the AUTOSAR Classic Platform Architecture

Fig. 4.53 AUTOSAR CDDs

4.11.3.2. Initialization

Cdd_Uart_Init() is the function responsible for initializing driver peripheral and opening its configured instances for transmission

4.11.3.3. States

UART driver maintains these below states as per the driver source condition:

1. CDD_UART_UNINIT

2. CDD_UART_INIT

4.11.3.4. Assumptions

For using DMA feature, driver assumes that cache initialization is done in application only and not done by the driver.

4.11.3.5. Limitations

None

4.11.3.6. Main Functions

1. Cdd_Uart_Read() - This API is used for reading data using a given channel ID upto a specified length

2. Cdd_Uart_Write() - This API is used for writing data using a given channel ID upto a specified data count

3. Cdd_Uart_Cancel() - This API is used for cancelling an ongoing data transfer using a given channel ID in the given direction

4. Cdd_Uart_GetRemainingWords() - This API is used for checking the remaining words count for an ongoing Interrupt or DMA mode data transfer

Note: Timeout Value parameter in Cdd_Uart_Read() and Cdd_Uart_Write() should be passed as number of ticks according to clock frequency. The clock source have changed from RTI timers which used 200MHz clock frequency to R5f timers which uses 400MHz clock frequency, so the timeout values need to be passed accordingly.

4.11.3.7. Design overview

Will be updated in future release

4.11.4. Hardware Features

4.11.4.1. IP Supported Features

• Interrupt, Polling And DMA Mode. For DMA mode, only trigger level 1 is supported

• Write, Read and Cancel Operation.

• Read Return Full & Partial Mode.

• Receiver line error status like overrun, framing.

4.11.4.2. Not supported Features

• MODEM control functions.

• Hardware Flow Control.

• Partial Mode is only supported in interrupt mode and returns FIFO level chars.

• IrDA and CIR Features.

4.11.4.3. Non compliance

4.11.4.3.1. Deviations to requirements (Requirement Traceability)

4.11.4.3.1.1. Deviation of requirements against AUTOSAR specification requirements

None

4.11.5. Source files

The files structure for the UART driver is similar to other drivers. The source is divided into headers under include/ and driver source within src/ directory under Uart driver path in MCAL. Cdd_Uart.c and Cdd_Uart.h are the 2 files that contain the provided driver API’s.

Static source C Files are defined below

📦AM263Px
┣ 📂build
┣ 📂mcal
┃ ┣ 📂Uart
┃ ┃ ┣ 📂include
┃ ┃ ┃ ┣ 📜Cdd_Uart.h : Shall specify the interface provided by the driver.
┃ ┃ ┃ ┣ 📜Cdd_Uart_Irq.h : contain interrupt service routines.
┃ ┃ ┣ 📂src
┃ ┃ ┃ ┣ 📜Cdd_Uart.c : Shall implement the CDD Uart driver functionality.
┃ ┃ ┃ ┣ 📜Cdd_Uart_Irq.c : contain interrupt service routines.
┃ ┃ ┣ 📂V0
┃ ┃ ┃ ┗ 📜Cdd_Uart_Priv.c : Shall implement the private functions.
┃ ┃ ┃ ┣ 📜Cdd_Uart_Priv.h : Contains device specific function declarations.
┃ ┃ ┃ ┣ 📜uart.c : Contains the UART driver implementations.
┃ ┃ ┃ ┣ 📜Uart.h : Contains Internal functions declarations for Uart driver.
┃ ┃ ┃ ┗ 📜uart_dma.h : Contains DMA related function declarations.
┃ ┃ ┃ ┣ 📜uart_dma_edma.c : Contains functions that support the Enhanced DMA mode for use with UART channels in DMA mode as IO mode.
┃ ┃ ┗ 📜Makefile
┃ 📂mcal_config
┃ 📂mcal_docs
┃ 📜README.txt

Plugin files are defined below in the table.

Plugin Files	Description
Cdd_Uart_Cfg.h	Contains the Precompile switches and Symbolic names
Cdd_Uart_Cfg.c	Contains all Pre-Compile Configured parameters
Cdd_Uart_PBcfg.c	Contains all Post-Build Configured parameters

4.11.6. Module requirements

Please refer Software Product Specification document provided as part of CSP.

4.11.6.1. Memory Mapping

Memory Mapping Sections	CDD_UART_CODE	CDD_UART_CODE_ISR	CDD_UART_VAR_NO_INIT	CDD_UART_VAR_ZERO_INIT	CDD_UART_PBCFG	CDD_UART_PBCFG_ROOT
CDD_UART_START_SEC_VAR_INIT_UNSPECIFIED(.bss)				x
CDD_UART_STOP_SEC_VAR_INIT_UNSPECIFIED				x
CDD_UART_START_SEC_CODE_APPL(.text)		x
CDD_UART_STOP_SEC_CODE_APPL		x
CDD_UART_START_SEC_VAR_UNSPECIFIED(.data)			x
CDD_UART_STOP_SEC_VAR_UNSPECIFIED			x
CDD_UART_START_SEC_CODE(.text)	x
CDD_UART_STOP_SEC_CODE	x
CDD_UART_START_SEC_PBCFG(.data)					x
CDD_UART_STOP_SEC_PBCFG					x
CDD_UART_START_SEC_PBCFG_ROOT(.const)						x
CDD_UART_STOP_SEC_PBCFG_ROOT						x

4.11.6.2. Scheduling

There are no scheduled functions within the CDD UART driver

4.11.6.3. Error handling

4.11.6.3.1. Development Error Reporting (DET)

The Cdd_UartDriver will report development errors on enabling UART_DEV_ERROR_DETECT == STD_ON in Cdd_Uart_Cfg.h

Refer API documentation for list of development errors reported by UART Driver

4.11.6.3.2. 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-/disabled separately. Refer to the configuration chapter where the en-/disabling of the checks is described. En-/disabling of single checks is an addition to the AUTOSAR standard which requires to en-/disable the complete parameter checking via the parameter UART_DEV_ERROR_DETECT.

4.11.6.3.3. Production Code Error Reporting

By default, production code related errors are reported to the DEM using the service DEM_ReportErrorStatus().

4.11.7. Used resources

4.11.7.1. Interrupt Handling

Following Interrupt Service Routines are present in UART:

1. Cdd_Uart_ChannelIsr - The Channel-based Interrupt Subroutine calls handler function based on the selected channel.

2. CDD_EDMA_lld_transferCompletionMasterIsrFxn - The common-channel DMA-based Interrupt Subroutine calls handler function available for transfer completion.

4.11.8. Integration description

4.11.8.1. Dependent modules

4.11.8.1.1. DET

The module UART depends on the DET (by default) in order to report development errors. Detection and reporting of development errors, DET shall be enabled or disabled by the switch CDD_UART_DEV_ERROR_DETECT = STD_ON in Cdd_Uart_Cfg.h, generated by using appropriate option check within the configurator plugin. The DET can be replaced optionally by an equivalent component which is responsible to recognize development errors, if no DET component is available.

4.11.8.1.2. MCU

The Cdd_Uart Modules expects the MCU modules to enable the GPIO registers used used by configuring the PRCM correctly. MCU module is responsible for setting up clock configuration for the driver, the hardware clock available on the board.

4.11.8.1.3. PORT

The Cdd_Uart Modules expects that PinMux is set correctly to configure the GPIO pins for appropriate UART channel ports. The pin direction shall also be set by the PORT driver

4.11.8.1.4. Callback Functions

The UART driver provides read, write and error call back functions supported for all channels targeted from UART Configurator Plugin

4.11.8.1.5. SchM (Optional)

If multiple AUTOSAR runnables have access to the same Data Store Memory block, the exported AUTOSAR specification enforces data consistency by using an AUTOSAR exclusive area. With this specification, the runnables have mutually exclusive access to the per-instance memory global data, which prevents data corruption. Beside the OS, the BSW Scheduler provides functions that UART module calls at begin and end of critical sections. This implementation requires 1 level of exclusive access to guard critical sections.

The data consistency mechanism that has to be applied to an ExclusiveArea might be domain, ECU or even project specific. The decision which mechanism has to be applied by RTE / Basic Software Scheduler is taken during ECU integration by setting the Exclusive Area configuration parameter RteExclusiveAreaImplMechanism. This parameter is an input for RTE generator. For UART Module, data consistency and exclusive access to critical sections are required for the following sections as shown in the table below:

Exclusive Area Functions used	UART Function calling Exclusive Area	Need for Exclusive Area	Recommended Exclusive Area Mapping
UART_EXCLUSIVE_AREA_0	UART_writeCancelNoCB UART_writeCancelDmaNoCB UART_readCancelNoCB UART_readCancelDmaNoCB	To protect against multiple access for shared resources	ALL_INTERRUPT_BLOCKING : All interrupts should be blocked as this API’s can be called in the interrupts

4.11.8.2. Multi-core support

Not supported

4.11.9. Configuration

4.11.9.1. CddUartDriver

This container contains the configuration parameters and sub containers of the AUTOSAR Complex device driver (CDD) module.

4.11.9.1.1. CddUartChannel

Configuration of an individual UART channel.

4.11.9.1.1.1. CddUartHwID

Item
Name	CddUartHwID
Description	This parameter contains the Channel ID of UART port in the device.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_CHANNEL_ID_0
Range	CDD_UART_CHANNEL_ID_0 CDD_UART_CHANNEL_ID_1 CDD_UART_CHANNEL_ID_2 CDD_UART_CHANNEL_ID_3 CDD_UART_CHANNEL_ID_4 CDD_UART_CHANNEL_ID_5

4.11.9.1.1.2. CddUartClockFrequency

Item
Name	CddUartClockFrequency
Description	This parameter indicates the input clock frequency from the device.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	48000000
Max-value	1000000000
Min-value	32000

4.11.9.1.1.3. CddUartBaudRate

Item
Name	CddUartBaudRate
Description	This parameter contains the desired Baud Rate to be used for transmission of signals.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	115200
Max-value	12000000
Min-value	2400

4.11.9.1.1.4. CddUartIOMode

Item
Name	CddUartIOMode
Description	This parameter identifies the UART operational mode for the configured IP.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_MODE_INTERRUPT
Range	CDD_UART_MODE_POLLING CDD_UART_MODE_INTERRUPT CDD_UART_MODE_DMA

4.11.9.1.1.5. CddUartTXTriggerLevel

Item
Name	CddUartTXTriggerLevel
Description	This parameter identifies the UART transmission trigger level threshold for the configured UART.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_TRIGGER_LEVEL_16
Range	CDD_UART_TRIGGER_LEVEL_1 CDD_UART_TRIGGER_LEVEL_8 CDD_UART_TRIGGER_LEVEL_16 CDD_UART_TRIGGER_LEVEL_32 CDD_UART_TRIGGER_LEVEL_56

4.11.9.1.1.6. CddUartRXTriggerLevel

Item
Name	CddUartRXTriggerLevel
Description	This parameter identifies the UART trigger level threshold during receival for the configured UART.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_TRIGGER_LEVEL_16
Range	CDD_UART_TRIGGER_LEVEL_1 CDD_UART_TRIGGER_LEVEL_8 CDD_UART_TRIGGER_LEVEL_16 CDD_UART_TRIGGER_LEVEL_56 CDD_UART_TRIGGER_LEVEL_60

4.11.9.1.1.7. CddUartWordLength

Item
Name	CddUartWordLength
Description	This parameter identifies the word length for the packets used in data transmission with UART.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_WORD_LENGTH_8
Range	CDD_UART_WORD_LENGTH_5 CDD_UART_WORD_LENGTH_6 CDD_UART_WORD_LENGTH_7 CDD_UART_WORD_LENGTH_8

4.11.9.1.1.8. CddUartParity

Item
Name	CddUartParity
Description	This parameter specifies the parity of the bits transferred.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_PARITY_NONE
Range	CDD_UART_PARITY_NONE CDD_UART_PARITY_ODD CDD_UART_PARITY_EVEN

4.11.9.1.1.9. CddUartReadReturnModes

Item
Name	CddUartReadReturnModes
Description	This parameter identifies the UART read return modes.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_FULL_READ_RETURN
Range	CDD_UART_FULL_READ_RETURN CDD_UART_PARTIAL_READ_RETURN

4.11.9.1.1.10. CddUartOperatingModes

Item
Name	CddUartOperatingModes
Description	This parameter identifies the UART operational mode for the configured channels.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_16x_OPER
Range	CDD_UART_13x_OPER CDD_UART_16x_OPER CDD_UART_16x_AUTO_OPER

4.11.9.1.1.11. CddUartStopBits

Item
Name	CddUartStopBits
Description	This parameter specifies the size of stop bits to use in data packets.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CDD_UART_STOP_BIT_1
Range	CDD_UART_STOP_BIT_1 CDD_UART_STOP_BITS_2

4.11.9.1.1.12. CddUartReadNotificationHandler

Item
Name	CddUartReadNotificationHandler
Description	This parameter is a read notification handler function.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CddUart_CallbackReadNotify

4.11.9.1.1.13. CddUartWriteNotificationHandler

Item
Name	CddUartWriteNotificationHandler
Description	This parameter is a write notification handler function.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CddUart_CallbackWriteNotify

4.11.9.1.1.14. CddUartErrorNotificationHandler

Item
Name	CddUartErrorNotificationHandler
Description	This parameter is a error notification handler function.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	CddUart_CallbackErrorNotify

4.11.9.1.1.15. CddUartHwUnitCddDmaTxHandler

Item
Name	CddUartHwUnitCddDmaTxHandler
Description	References the CDD DMA handler used for CDD UART transmission
Multiplicity-Configuration-Class	–
Post-Build Time	VARIANT-POST-BUILD
Pre-Compile Time	VARIANT-PRE-COMPILE
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE

4.11.9.1.1.16. CddUartHwUnitCddDmaRxHandler

Item
Name	CddUartHwUnitCddDmaRxHandler
Description	References the CDD DMA handler used for CDD UART reception
Multiplicity-Configuration-Class	–
Post-Build Time	VARIANT-POST-BUILD
Pre-Compile Time	VARIANT-PRE-COMPILE
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE

4.11.9.2. CddUartGeneral

Item
Name	CddUartGeneral
Description	Switches the Cdd_Uart_GetVersionInfo function ON or OFF.
Post-build-variant-multiplicity	false
Origin	Texas Instruments
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.1. CddUartRegisterReadbackApi

Item
Name	CddUartRegisterReadbackApi
Description	Switches the Cdd_Uart_RegisterReadback function ON or OFF.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.2. CddUartDeinitApi

Item
Name	CddUartDeinitApi
Description	Switches the Cdd_Uart_DeInit function ON or OFF.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.3. CddUartWriteApi

Item
Name	CddUartWriteApi
Description	Switches the Cdd_Uart_Write function ON or OFF.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.4. CddUartReadApi

Item
Name	CddUartReadApi
Description	Switches the Cdd_Uart_Read function ON or OFF.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.5. CddUartCancelApi

Item
Name	CddUartCancelApi
Description	Switches the Cdd_Uart_Cancel function ON or OFF.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.6. CddUartGetRemainingWordsApi

Item
Name	CddUartGetRemainingWordsApi
Description	Switches the Cdd_Uart_GetRemainingWords API which returns the remaining words to be transferred from the active device UART instance.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.7. CddUartDevErrorDetect

Item
Name	CddUartDevErrorDetect
Description	Switches the Development Error Detection and Notification ON or OFF.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	true

4.11.9.2.8. CddUartIrqType

Item
Name	CddUartIrqType
Description	This parameter contains a reference to the OsCounter, which is used by the UART driver.
Origin	Texas Instruments
Post-build-variant-multiplicity	false
Post-Build-Variant-Value	false
Value-Configuration-Class	–
Post-Build-Time	VARIANT-POST-BUILD
Pre-Compile-Time	VARIANT-PRE-COMPILE
Default-value	0
Range	CDD_UART_ISR_VOID CDD_UART_ISR_CAT1 CDD_UART_ISR_CAT2
Multiplicity-Configuration-Class	–
Post-Build Time	VARIANT-POST-BUILD
Pre-Compile Time	VARIANT-PRE-COMPILE
Max-value	16
Min-value	0

For using UART with DMA mode, take additional care with these configuration value with CDD DMA configuration:

• separate DMA configuration shall be done for Tx and/or Rx of each UART instance configured for DMA IO mode using the CDD DMA configurator plugin. Make sure to set CddDmaInterruptEnable option provided there as UART peripheral shall make use of enhanced DMA with interrupt enabled.

• UART Tx makes use of two parameters for Tx and Dummy param sets to service a dummy transfer request at the end as expected from HW IP. So make sure to have corresponding two parameter sets registered in a channel group on configurator plugin.

4.11.10. Examples

4.11.10.1. Overview

1. Initialize MCU and Port using Mcu_Init() and Port_Init()

2. Configure the interrupt using Cdd_Uart_InterruptConfiguration()

3. For DMA Echo test, Initialize the DMA using API Cdd_Dma_Init()

4. Initialize the UART peripheral using API Cdd_Uart_Init()

5. Select the channel and buffer pointers for read and write

6. Write the sample message to the terminal

7. Write the message from Write buffer to the terminal to input the characters using Cdd_Uart_Write()

8. Read the input message using Cdd_Uart_Read() and store it in the Read buffer

9. Again write the message back which is read to echo the read message to the terminal

10. Write the message to inform the echo has been completed

Note: By default UART0 instance is configured. For using UART1 instance of AM263x SOC, Configuration to be done in Tresos and channel name has to be modified in example application

4.11.10.2. Hardware Software Setup and Tools

1. For testing UART1 instance in AM263x SOC, external Serial to USB convertor and docking station (HSEC 180 pin connector) is required.

2. Connect the AM263x SOC to the docking station

3. Do the connections as below

   HSEC Connector Serial to USB Convertor UART1 TxD pin (pin #162) Rx pin UART1 RxD pin (pin #161) Tx pin Ground Ground

4. Connect the COM port with configured settings and run the example

4.11.10.3. Steps to build and run example

CDD UART DMA example application demonstrating the CDD UART driver features is present in Uart/uart_echo_dma_app under /examples folder.

The UART example app used to verify the data transmission and reception through a selected channel ID 0 of the available UART Hardware Units.

This application can be built from the build folder by running gmake –s uart_echo_dma_app PLATFORM=am263px.

The details of running the application and the setup required is part of the MCAL User Guide.

4.11.10.4. Example Logs

This is Uart Echo Test in DMA Mode
Please input 8 characters:
texusins
Echo has been completed.

All tests have passed!

4.11.10.5. File Structure

📦AM263Px
┣ 📂build
┣ 📂mcal
┃ ┣ 📂examples
┃ ┃ ┣ 📂Uart
┃ ┃ ┃ ┣ 📂uart_echo_dma_app
┃ ┃ ┃ ┃ ┣ 📂soc
┃ ┃ ┃ ┃ ┣ 📜Makefile
┃ ┃ ┃ ┃ ┣ 📜UartEchoDma.c : Contains UART Echo DMA test example.
┃ ┃ ┃ ┃ ┣ 📜UartEchoDma.h : Contains UART Echo DMA test example header.
┃ ┣ 📂examples_config
┃ ┃ ┣ 📂Uart_Demo_Cfg
┃ ┃ ┃ ┣ 📂soc
┃ ┃ ┃ ┃ ┣ 📂am263px
┃ ┃ ┃ ┃ ┃ ┣ 📂r5f0_0
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📂include
┃ ┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Uart_Cfg.h : Contains the Precompile switches, Symbolic names.
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📂src
┃ ┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Uart_Cfg.c : Contains all Pre-Compile Configured parameters
┃ ┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Uart_PBcfg.c : Contains all Post-Build Configured parameters
┃ 📂mcal_config
┃ 📂mcal_docs
┣ 📜README.txt

4.11.11. FAQ’s

None

4.11.12. References

Technical Reference Manual