5.12. CDD DMA Module

5.12.1. Acronyms and Definitions

Abbreviation/Term

Explanation

AUTOSAR

Automotive Open System Architecture

CDD

Complex Device Driver

DMA

Direct Memory Access

RTDMA

Real-Time Direct Memory Access

API

Application Programming Interface

DET

Default Error Tracer

MPU

Memory Protection Unit

ESM

Error Signaling Module

SSU

Safety and Security Unit

HW

Hardware

SW

Software

5.12.2. Introduction

The CDD DMA driver is a Complex Device Driver that provides a hardware method of transferring data between peripherals and/or memory without intervention from the CPU.

CDD DMA MCAL AUTOSAR

Fig. 5.43 Cdd Dma MCAL AUTOSAR

This document details AUTOSAR Cdd DMA module implementation

Supported AUTOSAR Release

4.3.1

Supported Configuration Variants

Pre-Compile

Vendor ID

CDD_DMA_VENDOR_ID (44)

Module ID

CDD_DMA_MODULE_ID (255)

5.12.3. Functional Overview

The CDD DMA driver is part of the Complex Device Driver layer (CDD). The RTDMA provides a hardware method of transferring data between peripherals and/or memory without CPU intervention.

The RTDMA operates as a state machine with two nested loops that control data transfers:

5.12.3.1. Burst and Transfer Loops

The RTDMA uses a two-level nested loop structure to manage data transfers:

  1. Burst Loop (Inner Loop): The inner loop transfers a configured number of words (bytes) called a “burst”. The burst size is specified by the BURST_SIZE and represents the smallest amount of data transferred at one time.

  2. Transfer Loop (Outer Loop): The outer loop repeats the burst operation for a configured number of times called “transfers”. The transfer size is specified by the TRANSFER_SIZE.

Transfer Process:

  • A DMA transfer is initiated by a peripheral or software trigger

  • The inner burst loop executes, transferring the configured burst size

  • After completing one burst, the next burst begins (if more transfers are pending)

  • This continues until all configured transfers are complete

  • Upon completion, a user-configurable notification callback can be invoked. The notification timing can be configured to trigger either at the beginning of a new transfer or at the end of the complete transfer.

5.12.3.2. Operating Modes

One-Shot Mode:

  • When enabled: After the first trigger event, the DMA continuously transfers data in bursts until all configured transfers are complete

  • When disabled: A separate trigger event is required for each burst transfer, continuing until all configured transfers are complete

Warning

One-shot mode must not be used with Priority 0 channels. When one-shot mode is enabled, a single trigger can consume the majority of RTDMA bandwidth, potentially causing long CPU stalls as the DMA continuously processes bursts without allowing other channels to execute. This is especially problematic with Priority 0 channels, which can interrupt other ongoing transfers.

Recommendation: Configure a CPU timer (or similar periodic trigger) and disable one-shot mode to ensure controlled, time-sliced DMA operation that prevents bandwidth monopolization and CPU stalls.

Continuous Mode:

  • When enabled: The RTDMA keeps the channel active even after all bursts in the transfer loop are complete. The channel remains ready to process the next transfer automatically

  • When disabled: The RTDMA disables the channel after all bursts in the transfer loop are complete. The channel stops and must be re-enabled before another transfer can be started

Note

One-shot mode and continuous mode are independent settings and can be enabled or disabled separately. Each mode controls a different aspect of the transfer behavior:

  • One-shot mode controls whether multiple bursts execute from a single trigger

  • Continuous mode controls whether the channel remains active after completing all transfers

5.12.3.3. Channel Priority

The RTDMA supports software-configurable priority levels for efficient channel arbitration:

Round Robin Mode:

  • All channels have equal priority

  • Each enabled channel is serviced in round-robin fashion: CH1 → CH2 → CH3 → … → CH10 → CH1

  • After each channel transfers a burst, the next channel is serviced

Software-Configurable Priority (0-3):

  • Each channel can be assigned a priority level from 0 to 3

  • Default priority for all channels is 1

  • Lower priority number = higher priority during arbitration

  • When multiple channels have the same priority, the lowest channel number wins arbitration

Priority 0 (Highest Priority):

  • Channels configured with priority 0 are considered a special case and can interrupt the RTDMA state machine

  • When a Priority 0 event occurs, the current word transfer on any other channel completes, then execution halts

  • The Priority 0 channel is then serviced for its complete burst

  • After the Priority 0 channel burst is complete, execution returns to the channel that was active when the Priority 0 event occurred

  • Typically used for time-critical peripherals

5.12.3.4. Overrun Detection

The RTDMA includes overrun detection logic to identify when trigger events are lost:

  • When a burst for a channel starts, the peripheral interrupt flag is cleared

  • If an additional event trigger arrives between the time the flag is set and cleared by the burst start, the second trigger is lost

  • This overrun condition is detected and flagged by the RTDMA

  • Users can configure overrun notification to receive a callback when an overrun condition occurs.

5.12.3.5. Memory Protection Unit (MPU)

The RTDMA includes an integrated MPU for access protection and security:

MPU Features:

  • Monitors DMA read/write interface buses continuously

  • Detect errors, block access, and trigger an interrupt on any violations

  • Supports up to 16 configurable memory regions

  • Each region defines start and end addresses for read/write access permissions

  • Channel-to-MPU mapping is orthogonal - each channel can be enabled in multiple MPU regions and vice versa

MPU Operation:

  • When MPU is enabled, faults are communicated to the Error Signaling Module (ESM)

  • MPU checks if an address belongs to any defined region

  • MPU verifies that accesses have necessary permissions for the region

  • Access violations result in blocked transactions and error reporting to Error Signaling Module (ESM)

5.12.4. Hardware Features

5.12.4.1. Hardware Features Supported

Features supported at a high level are:

  • 10 RTDMA channels with software configurable priority levels and independent Interrupt Controller interrupts

  • Up to 256 hardware trigger sources to initiate RTDMA transfers

  • Internal trigger generation for data transfers and trigger sources for channels

  • Independent Read and Write buses

  • Word Size: 8-bit, 16-bit, 32-bit, and 64-bit transfers

  • Throughput: 1 cycle/word after the initial read-write access with 0 cycle read/write stall

  • FIFO implemented within hardware to optimize data transfers

  • Linear and circular addressing modes

  • Support for multiple data transformation functions as data is transferred from source to destination

    • Ability to reverse words, half words, and so on

  • Access protection through the Memory Protection Unit (MPU)

5.12.4.2. Not supported Features

  • Burst Mode Support for transfers with EMIF, since EMIF is not available on automotive devices

5.12.4.3. Non compliance

None

5.12.5. Source files

📦f29h85x_mcal
┣ 📂build
┣ 📂docs
┣ 📂drivers
┃ ┣ 📂BSW_Stubs
┃ ┣ 📂Adc
┃ ┣ 📂Can
┃ ┗ 📂Cdd_Dma
┃ ┃ ┣ 📂include
┃ ┃ ┃ ┣ 📜Cdd_Dma.h : Contains the API declarations of the Cdd DMA driver to be used by upper layers.
┃ ┃ ┃ ┗ 📜Cdd_Dma_Priv.h : Contains data structures and Internal function declarations.
┃ ┃ ┣ 📂src
┃ ┃ ┃ ┣ 📜Cdd_Dma.c : Contains the implementation of the API for Cdd DMA driver.
┃ ┃ ┃ ┣ 📜Cdd_Dma_Irq.c : Contains the ISR implementation.
┃ ┃ ┃ ┗ 📜Cdd_Dma_Priv.c : Contains Functions that support the API for Cdd DMA driver
┃ ┃ ┗ 📜CMakeLists.txt
┃ ┣ 📂Dio
┃ ┣ 📂Gpt
┃ ┣ 📂hw_include
┃ ┣ 📂Mcal_Lib
┃ ┣ 📂Mcu
┃ ┣ 📂Port
┃ ┣ 📂Spi
┃ ┗ 📂Wdg
┣ 📂examples
┣ 📂plugins
┣ 📜CMakeLists.txt
┗ 📜CMakePresets.json

Cdd DMA Header File Structure

Fig. 5.44 Cdd DMA Header File Structure

5.12.6. Module requirements

5.12.6.1. Memory Mapping

The driver follows the AUTOSAR memory mapping strategy. All memory sections should be stored in memory as per AUTOSAR specifications, considering initialization policy, alignment requirements, safety classification, and core scope where applicable.

Reference memory map files can be found at:

{MCAL_INSTALL_PATH}\drivers\BSW_Stubs\MemMap\include

The memory sections are organized according to AUTOSAR specifications to ensure proper placement of code and data in different memory regions based on their usage and access patterns.

5.12.6.2. Scheduling

None

5.12.6.3. Error handling

5.12.6.3.1. Development Error Reporting

Development errors are reported to the DET using the service Det_ReportError(), when enabled. The driver interface contains the MACRO declaration of the error codes to be returned.

5.12.6.4. Error codes

Type of Error

Related Error code

Value (Hex)

API service used without module initialization

CDD_DMA_E_UNINIT

0x0A

API called for reinitialization of already initialized DMA driver

CDD_DMA_E_ALREADY_INITIALIZED

0x0B

Initialization API failed

CDD_DMA_E_INIT_FAILED

0x0C

API service called with invalid parameter pointer

CDD_DMA_E_PARAM_POINTER

0x0D

API service called with invalid parameter value

CDD_DMA_E_PARAM_VALUE

0x0E

API service called during ongoing process

CDD_DMA_E_BUSY

0x0F

API service called to force or clear peripheral event trigger when peripheral event trigger is disabled

CDD_DMA_E_PERIPHERAL_EVENT_TRIGGER_DISABLED

0x10

API service called to enable peripheral event trigger when peripheral event trigger is already enabled

CDD_DMA_E_PERIPHERAL_EVENT_TRIGGER_ENABLED

0x11

API service called to start a channel when the channel is already running

CDD_DMA_E_ALREADY_RUNNING

0x12

API service called to halt a channel when the channel already halted

CDD_DMA_E_ALREADY_HALTED

0x13

API service called to modify DMA configurable properties when DMA configurable properties are committed

CDD_DMA_E_DMACFG_COMMITTED

0x14

API service called to modify DMA channel properties when DMA channel properties are committed

CDD_DMA_E_CHCFG_COMMITTED

0x15

API service called to modify DMA MPU region properties when DMA MPU region properties are committed

CDD_DMA_E_MPUR_COMMITTED

0x16

API service called to enable or disable MPU when DMA MPU configuration are committed

CDD_DMA_E_MPUCFG_COMMITTED

0x17

API service called to clear error flag when no overflow is detected

CDD_DMA_E_NO_OVERFLOW

0x18

API service called to clear peripheral event trigger when no event trigger exists

CDD_DMA_E_NO_TRIGGER

0x19

5.12.7. Used resources

5.12.7.1. Interrupt Handling

Each RTDMA channel has its own independent Interrupt Controller interrupt for CPU servicing. The DMA can generate interrupts at the completion of a transfer, at the beginning of the transfer process and during overrun detection. These interrupts allow the CPU to be notified of transfer completion or errors without polling.

The Driver doesn’t register any interrupts handler (ISR), it’s expected that consumer of this driver registers the required interrupt handler.

For every RTDMA channel, an ISR requires to be registered if Channel notification is enabled. The Interrupt number associated with RTDMA channel is detailed in TRM (also, please refer the Example application). Interrupt category should be selected in the Cdd_Dma plugin.

Cdd Dma Instance

Interrupt Name

Interrupt handler

RTDMA1

RTDMA1_CH1INT

Cdd_Dma_RTDMA1_CH1_Isr

RTDMA1

RTDMA1_CH2INT

Cdd_Dma_RTDMA1_CH2_Isr

RTDMA1

RTDMA1_CH3INT

Cdd_Dma_RTDMA1_CH3_Isr

RTDMA1

RTDMA1_CH4INT

Cdd_Dma_RTDMA1_CH4_Isr

RTDMA1

RTDMA1_CH5INT

Cdd_Dma_RTDMA1_CH5_Isr

RTDMA1

RTDMA1_CH6INT

Cdd_Dma_RTDMA1_CH6_Isr

RTDMA1

RTDMA1_CH7INT

Cdd_Dma_RTDMA1_CH7_Isr

RTDMA1

RTDMA1_CH8INT

Cdd_Dma_RTDMA1_CH8_Isr

RTDMA1

RTDMA1_CH9INT

Cdd_Dma_RTDMA1_CH9_Isr

RTDMA1

RTDMA1_CH10INT

Cdd_Dma_RTDMA1_CH10_Isr

RTDMA2

RTDMA2_CH1INT

Cdd_Dma_RTDMA2_CH1_Isr

RTDMA2

RTDMA2_CH2INT

Cdd_Dma_RTDMA2_CH2_Isr

RTDMA2

RTDMA2_CH3INT

Cdd_Dma_RTDMA2_CH3_Isr

RTDMA2

RTDMA2_CH4INT

Cdd_Dma_RTDMA2_CH4_Isr

RTDMA2

RTDMA2_CH5INT

Cdd_Dma_RTDMA2_CH5_Isr

RTDMA2

RTDMA2_CH6INT

Cdd_Dma_RTDMA2_CH6_Isr

RTDMA2

RTDMA2_CH7INT

Cdd_Dma_RTDMA2_CH7_Isr

RTDMA2

RTDMA2_CH8INT

Cdd_Dma_RTDMA2_CH8_Isr

RTDMA2

RTDMA2_CH9INT

Cdd_Dma_RTDMA2_CH9_Isr

RTDMA2

RTDMA2_CH10INT

Cdd_Dma_RTDMA2_CH10_Isr

5.12.7.2. Instance support

CPU instances

supported

CPU 1

YES

CPU 2

NO

CPU 3

NO

5.12.7.3. Hardware-Software Mapping

Below image shows Cdd DMA driver Hardware-Software mapping. For more information related to HW/SW mapping, refer the F29x Reference Manual.

Cdd DMA HW/SW Mapping

Fig. 5.45 Cdd DMA HW/SW Mapping

5.12.8. Integration description

5.12.8.1. Dependent modules

5.12.8.1.1. DET

This implementation depends on the DET in order to report development errors. The detection of development errors is configurable (ON / OFF). The switch CDD_DMA_DEV_ERROR_DETECT will activate or deactivate the detection of all development errors.

5.12.8.1.2. MCU

MCU Module is required to initialize all the clocks to be used by different peripherals including the RTDMA module.

5.12.8.2. Resource Allocator

The CDD DMA module uses the Resource Allocator to allocate RTDMA peripheral instances and channels to CPU cores and configure their memory-mapped base addresses and global properties. Each allocation is placed inside a Context that maps to a CPU core (e.g. CPU1). The CurrentContext parameter in the Resource Allocator selects which Context is active for MCAL execution. See the Resource Allocator Module User Guide for details on configuring device-specific settings.

The Frame parameter (FRAME0–FRAME3) selects the memory-mapped frame for the instance, enabling simultaneous access from different initiators without arbitration stalls. The BaseAddr is auto-calculated based on the selected instance, channel, and frame. Additional global RTDMA properties including priority schemes, emulation mode, channel priorities, and MPU configuration are also configured through the Resource Allocator.

5.12.8.2.1. Why Global-Level Configuration is Necessary

The F29 device architecture requires certain RTDMA configuration registers to be writable only by CPU1. These include:

  • Priority Scheme (Round-robin vs. Software-configured)

  • Emulation Mode (Stop vs. Free-run during debug halt)

  • Channel Priorities (Priority levels 0-3 for each channel)

  • MPU Configuration (Memory Protection Unit regions and permissions)

When SDK RTDMA is used on CPU2 or CPU3, these cores cannot directly configure the above global properties due to hardware write restrictions. Therefore, the Resource Allocator provides a centralized global configuration mechanism where:

  1. CPU1 configures all global DMA properties in the Resource Allocator

  2. Individual channels are then allocated to different CPU contexts (CPU1, CPU2, CPU3)

  3. Each CPU context can configure channel-specific properties (source/destination addresses, transfer sizes, triggers, etc.)

This separation ensures that global hardware settings are properly initialized by CPU1 through the Resource Allocator, while each CPU can independently manage its allocated channels for data transfers using the appropriate driver interface.

5.12.8.2.2. Configuration Architecture

The DMA channel allocation follows a two-level hierarchical structure:

  1. Global Cdd_Dma Configuration Level (ResourceAllocatorGeneral/Cdd_Dma): Defines available hardware instances, their global properties, and channels

  2. CPU Context Configuration Level (ResourceAllocatorGeneral/Context/Cdd_Dma): Allocates specific channels from the global pool to individual CPU contexts

5.12.8.2.3. Resource Allocator Usage Example

To allocate RTDMA1 Channel 1 to CPU1 using FRAME0:

5.12.8.2.3.1. Step 1: Global Cdd_Dma Configuration (CPU1-Only Writable Settings)

At the global level (ResourceAllocatorGeneral/Cdd_Dma), configure the RTDMA hardware instance and its global properties. These settings must be configured here because they are only writable by CPU1:

  1. Create a new CddDmaHwInstance (e.g., RTDMA1)

  2. Set InstanceName to RTDMA1 or RTDMA2

  3. Set Frame to FRAME0, FRAME1, FRAME2, or FRAME3 (applies to all channels in this instance)

  4. Configure CddDmaPriorityScheme:

    • CDD_DMA_PRIORITY_ROUND_ROBIN: All channels have equal priority, serviced sequentially

    • CDD_DMA_PRIORITY_SOFTWARE_CONFIG: Channels use priority levels (0-3) configured per channel

  5. Configure CddDmaEmulationMode:

    • CDD_DMA_EMULATION_STOP: DMA halts during debugger breakpoints

    • CDD_DMA_EMULATION_FREE_RUN: DMA continues running during debugger breakpoints

  6. Configure CddDmaMpuEnable (true/false) to enable Memory Protection Unit

  7. If MPU is enabled, configure CddDmaMpuRegion containers:

    • Set CddDmaMpuRegionId (MPU1-MPU16)

    • Set CddDmaMpuStartAddress and CddDmaMpuEndAddress (4KB aligned)

    • Set CddDmaMpuAccessPermission (NO_ACCESS, READ_ACCESS, or READ_WRITE_ACCESS)

    • Add CddDmaMpuChannelEnable references to channels that can access this region

  8. Add CddDmaChannel containers for each channel you want to make available (CH1, CH2, …, CH10)

  9. For each channel:

    • Set ChannelName (CH1, CH2, …, CH10)

    • Set CddDmaChannelPriority (0-3, only used if priority scheme is SOFTWARE_CONFIG)

    • The BaseAddr will be automatically calculated (e.g., RTDMA1CH1_BASE_FRAME(0U))

ResourceAllocatorGeneral
└── Cdd_Dma
    └── CddDmaHwInstance_RTDMA1
        ├── InstanceName: RTDMA1
        ├── Frame: FRAME0
        ├── CddDmaPriorityScheme: Software-configured
        ├── CddDmaEmulationMode: Free-run
        └── CddDmaChannel_CH1
            ├── ChannelName: CH1
            ├── BaseAddr: RTDMA1CH1_BASE_FRAME(0U)  [auto-calculated]
            └── CddDmaChannelPriority: 1

Important Constraints:

  • All channels within a single RTDMA hardware instance must share the same frame selection. The frame is configured at the CddDmaHwInstance level, not at the individual channel level.

  • Global properties (priority scheme, emulation mode, channel priorities, MPU settings) are hardware instance-level settings and apply to all channels in that instance regardless of which CPU context they are allocated to.

5.12.8.2.3.2. Step 2: Context-Specific Channel Allocation

After defining channels in the global configuration, allocate them to specific CPU contexts:

  1. In the Resource Allocator configuration, navigate to the desired Context (e.g., CPU1_Context)

  2. Under Context/Cdd_Dma, create a new CddDmaAllocatedChannel

  3. Set ChannelRef to reference the global channel (e.g., /ResourceAllocatorGeneral/Cdd_Dma/CddDmaHwInstance_RTDMA1/CddDmaChannel_CH1)

ResourceAllocatorGeneral
└── Context (Core: CPU1)
    └── Cdd_Dma
        └── CddDmaAllocatedChannel
            └── ChannelRef: /ResourceAllocatorGeneral/Cdd_Dma/
                            CddDmaHwInstance_RTDMA1/CddDmaChannel_CH1

Key Points:

  • Each CddDmaHwInstance represents a physical RTDMA peripheral (RTDMA1 or RTDMA2)

  • A channel can only be allocated to one CPU context (enforced by uniqueness validation)

  • Only channels allocated to a context can be used by that context’s software

  • Once channels are allocated to a CPU context in the Resource Allocator, they are referenced in the Cdd_Dma module configuration

5.12.8.2.4. Multi-Core Usage Scenarios

5.12.8.2.4.1. Scenario 1: CPU1 using Cdd_Dma (AUTOSAR MCAL)

  • CPU1 configures global DMA properties in Resource Allocator (priority scheme, emulation mode, channel priorities, MPU)

  • Resource Allocator allocates channels to CPU1_Context

  • CPU1 calls Cdd_Dma_Init() to configure global DMA properties and initialize the driver

  • CPU1 uses Cdd_Dma APIs to configure channel-specific properties and perform transfers

5.12.8.2.4.2. Scenario 2: Mixed Usage (CPU1 with Cdd_Dma, CPU2/CPU3 with SDK RTDMA)

  • CPU1 configures global DMA properties for both RTDMA1 and RTDMA2 in Resource Allocator

  • Resource Allocator allocates RTDMA channels to CPU1_Context

  • Resource Allocator allocates RTDMA channels to CPU2_Context or CPU3_Context

  • CPU1 calls Cdd_Dma_Init() to configure global DMA properties and initialize the driver

  • CPU1 uses Cdd_Dma APIs for it’s channels

  • CPU2/CPU3 uses SDK RTDMA APIs for it’s channels

  • All CPUs operate independently on their allocated channels, but share the same global configuration set by CPU1

5.12.8.2.4.3. Scenario 3: CPU2/CPU3 using only SDK RTDMA

  • CPU1 configures global DMA properties for RTDMA instances in Resource Allocator (priority scheme, emulation mode, channel priorities, MPU)

  • Resource Allocator allocates RTDMA channels to CPU2_Context or CPU3_Context

  • CPU1 calls Cdd_Dma_Init() to configure global settings (even though CPU1 doesn’t use any DMA channels)

  • CPU2/CPU3 uses SDK RTDMA APIs for their allocated channels

  • This scenario requires Cdd_Dma_Init() on CPU1 to properly configure the global hardware settings that are only writable by CPU1

5.12.9. Configuration

The Cdd DMA Driver implementation supports single configuration variants, namely Pre-Compile config. The driver expects generated Cdd_Dma_Cfg.h to be present as input file. The associated Cdd DMA driver configuration generated source file is Cdd_Dma_Cfg.c.

The generated configuration files should not be modified manually. The config tool Elektrobit Tresos should be used to modify the configuration files.

Note

Refer section Getting Started with EB Tresos of Chapter MCAL Configuration and EB Tresos for more information on how to load plugin and generate the configuration files.

5.12.9.1. Configuration Parameters

5.12.9.1.1. CddDmaGeneral

Contains the general configuration parameters of the CDD DMA module.

5.12.9.1.1.1. CddDmaLockConfigurations

Item

Name

CddDmaLockConfigurations

Description

Enables locking of DMA configuration registers to prevent accidental modification during runtime. When enabled (true), the DMA configuration registers are write-protected after initialization.

Origin

Texas Instruments

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

false
5.12.9.1.1.2. CddDmaDevErrorDetect

Item

Name

CddDmaDevErrorDetect

Description

Switches the development error detection and notification on or off.

Origin

Texas Instruments

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

false
5.12.9.1.1.3. CddDmaVersionInfoApi

Item

Name

CddDmaVersionInfoApi

Description

Enables or disables the Cdd_Dma_GetVersionInfo() API.

Origin

Texas Instruments

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

false

5.12.9.1.2. CddDmaConfig

This container contains the configuration parameters and sub containers of the Cdd_Dma module.

5.12.9.1.2.1. CddDmaChannel

This container contains the driver configuration for the DMA channel.

5.12.9.1.2.2. CddDmaInstance

Item

Name

CddDmaInstance

Description

DMA instance ID derived from the selected channel reference. This is a non-editable parameter automatically populated based on CddDmaChannelRef.

Origin

Texas Instruments

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

RTDMA1

Range

RTDMA1
RTDMA2
5.12.9.1.2.3. CddDmaChannel

Item

Name

CddDmaChannel

Description

DMA channel ID derived from the selected channel reference. This is a non-editable parameter automatically populated based on CddDmaChannelRef.

Origin

Texas Instruments

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

CH1

Range

CH1
CH2
CH3
CH4
CH5
CH6
CH7
CH8
CH9
CH10
5.12.9.1.2.4. CddDmaInterruptCategory

Item

Name

CddDmaInterruptCategory

Description

This parameters defines the category of the interrupt.

Origin

Texas Instruments

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

ISR_CAT1_RTINT

Range

ISR_CAT1_INT
ISR_CAT1_RTINT
ISR_CAT2_INT
5.12.9.1.2.5. CddDmaChIntNotification

Item

Name

CddDmaChIntNotification

Description

Interrupt notification function for transfer

Multiplicity-Configuration-Class

–

Pre-Compile Time

VARIANT-PRE-COMPILE

Origin

Texas Instruments

Post-build-variant-multiplicity

false

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

NULL_PTR
5.12.9.1.2.6. CddDmaOverflowIntNotification

Item

Name

CddDmaOverflowIntNotification

Description

Overflow Interrupt notification function

Multiplicity-Configuration-Class

–

Pre-Compile Time

VARIANT-PRE-COMPILE

Origin

Texas Instruments

Post-build-variant-multiplicity

false

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

Default-value

NULL_PTR
5.12.9.1.2.7. CddDmaChannelRef

Item

Name

CddDmaChannelRef

Description

Reference to the RTDMA channel from the Resource Allocator. This links the configuration to a specific DMA channel available on the device.

Origin

Texas Instruments

Post-Build-Variant-Value

false

Value-Configuration-Class

–

Pre-Compile-Time

VARIANT-PRE-COMPILE

5.12.9.2. Steps To Configure Cdd DMA Module

  1. Open EB Tresos configurator tool.

  2. Ensure DMA channels have been allocated to the CPU context in the Resource Allocator module (see Resource Allocator section for details on channel allocation).

  3. Navigate to the Cdd_Dma module configuration.

  4. For each DMA channel to be used, create a CddDmaChannel container.

  5. Within each CddDmaChannel container, configure the following parameters:

    • CddDmaChannelRef: Reference to the allocated channel from the Resource Allocator path (ResourceAllocatorGeneral/Context/Cdd_Dma/CddDmaAllocatedChannel). This links the Cdd_Dma channel configuration to the channel allocated in the Resource Allocator.

    • CddDmaInterruptCategory: Select the interrupt category for the channel:

      • ISR_CAT1_INT

      • ISR_CAT1_RTINT

      • ISR_CAT2_INT

    • CddDmaChIntNotification: Specify the callback function name to be invoked when a DMA transfer completes on this channel.

    • CddDmaOverflowIntNotification: Specify the callback function name to be invoked when a DMA overflow interrupt occurs on this channel.\

  6. Save the configuration and generate the configuration files.

Note

Global configuration parameters such as channel ID, priority scheme, priorities, emulation mode and MPU configuration are managed in the Resource Allocator module, not in the Cdd_Dma module.

5.12.10. Examples

The example applications demonstrate use of the Cdd_Dma module. The examples are explained below in detail.

5.12.10.1. Cdd_Dma_Example_Mem_Transfer

5.12.10.1.1. Overview of Cdd_Dma_Example_Mem_Transfer

This example demonstrates basic memory-to-memory DMA transfer functionality:

  • Initialization

    • EcuM_Init() Initializes clock to 200 MHz using Mcu_Init()

    • Cdd_Dma_Init() initializes DMA driver with EB Tresos configuration

    • Cdd_Dma_GetVersionInfo() retrieves software version information (vendor ID, module ID, SW version)

  • Transfer Configuration

    • Configures DMA channel properties using Cdd_Dma_SetChannelProperties():

      • Software trigger mode (CDD_DMA_TRIGGER_SOFTWARE)

      • Continuous mode enabled

      • 32-bit data size for read and write operations

      • Channel interrupt enabled at end of transfer

      • Overflow interrupt disabled

    • Configures transfer parameters using Cdd_Dma_SetTransferProperties():

      • Burst size: 4 words (32-bit each)

      • Transfer size: 16 bursts (total 64 words = 256 bytes)

      • Source and destination step sizes: 4 bytes per word

      • No address wrapping (wrap size set to maximum 65535)

      • Source address: TxData buffer

      • Destination address: RxData buffer

  • Transfer Execution

    • Starts DMA channel using Cdd_Dma_StartChannelTransfer()

    • Triggers each burst individually using Cdd_Dma_ForcePeripheralEventTrigger()

    • Monitors burst status using Cdd_Dma_GetChannelStatus() to wait for burst completion

    • Verifies data integrity after each burst by comparing transmitted and received data

    • Receives interrupt notification via Cdd_Dma_Channel1_notification() callback when entire transfer completes

    • Stops DMA channel using Cdd_Dma_StopChannelTransfer()

    • Reports transfer success or failure based on data verification

5.12.10.1.2. Sample Log of Cdd_Dma_Example_Mem_Transfer

Executing Cdd_Dma_Example_Mem_Transfer example
---------------------------------------------------------------
CDD DMA MCAL Version Info
---------------------
Vendor ID           : 44
Module ID           : 255
SW Major Version    : 1
SW Minor Version    : 0
SW Patch Version    : 0
---------------------------------------------------------------
Data at source before transfer:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
Data at destination before transfer:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
Data at source after transfer:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
Data at destination after transfer:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
===============================================

Transfer successful

5.12.10.2. Cdd_Dma_Example_Mem_Transfer_Mpu

5.12.10.2.1. Overview of Cdd_Dma_Example_Mem_Transfer_Mpu

This example demonstrates RTDMA Memory Protection Unit (MPU) functionality by intentionally triggering an MPU violation:

  • Initialization

    • EcuM_Init() Initializes clock to 200 MHz using Mcu_Init()

    • Cdd_Dma_Init() initializes DMA driver with EB Tresos configuration

    • Cdd_Dma_GetVersionInfo() retrieves software version information (vendor ID, module ID, SW version)

  • MPU Configuration

    • Configures MPU region with specific address range:

      • MPU Region Start Address: 0x200E0000

      • MPU Region End Address: 0x200E0FFF

    • Places transmit buffer (TxData) at 0x200E0100 (within MPU region)

    • Places receive buffer (RxData) at 0x200E0FDC (intentionally extends outside MPU region to 0x200E101B)

    • This configuration intentionally causes MPU violation when DMA attempts to write to receive buffer

  • ESM and NMI Setup

    • Registers custom NMI handler CPU1_Custom_NMIHandler()

    • Configures Error Signaling Module (ESM)

  • Transfer Configuration

    • Configures DMA channel properties using Cdd_Dma_SetChannelProperties():

      • Software trigger mode (CDD_DMA_TRIGGER_SOFTWARE)

      • Continuous mode enabled

      • 32-bit data size for read and write operations

      • Channel interrupt enabled at end of transfer

      • Overflow interrupt disabled

    • Configures transfer parameters using Cdd_Dma_SetTransferProperties():

      • Burst size: 4 words (32-bit each)

      • Transfer size: 16 bursts (total 64 words = 256 bytes)

      • Source and destination step sizes: 4 bytes per word

      • No address wrapping (wrap size set to maximum 65535)

      • Source address: TxData buffer

      • Destination address: RxData buffer

  • When DMA attempts to write to receive buffer outside MPU region:

    • MPU detects security violation

    • MPU signals Error Aggregator module

    • Error Aggregator communicates fault to ESM

    • ESM triggers NMI interrupt and blocks RTDMA access

  • NMI handler increments g_nmiCount counter

    • Verifies NMI was triggered as expected, confirming MPU protection is functioning correctly

    • Reports pass if NMI occurred within timeout, fail otherwise

5.12.10.2.2. Sample Log of Cdd_Dma_Example_Mem_Transfer_Mpu

Executing Cdd_Dma_Example_Mem_Transfer_Mpu example
---------------------------------------------------------------
CDD DMA MCAL Version Info
  Vendor ID        : 44
  Module ID        : 255
  SW Major Version : 1
  SW Minor Version : 0
  SW Patch Version : 0
---------------------------------------------------------------

Starting DMA transfer...
Triggering DMA transfers (expecting MPU violation)...
---------------------------------------------------------------
Cdd_Dma_Example_Mem_Transfer_Mpu example passed - NMI was triggered as expected
---------------------------------------------------------------

5.12.10.3. Setup Required to Run Examples

  • Connect the hardware and power up

  • Connect UART setup to check the log on serial console

5.12.10.4. How to Run Examples

  • Open CCS and import the desired example (Cdd_Dma_Example_Mem_Transfer or Cdd_Dma_Example_Mem_Transfer_Mpu)

  • Build project and start debug session

  • Run the application and observe output on serial console

5.12.10.5. File Structure

📦f29h85x_mcal
┣ 📂build
┣ 📂docs
┣ 📂drivers
┣ 📂examples
┃ ┣ 📂AppUtils
┃ ┣ 📂Can
┃ ┣ 📂Cdd_Adc
┃ ┣ 📂Cdd_Dma
┃ ┃ ┣ 📂Cdd_Dma_Example_Mem_Transfer
┃ ┃ ┃ ┣ 📂Common
┃ ┃ ┃ ┃ ┗ 📂tresos
┃ ┃ ┃ ┃ ┗ 📂config
┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma.xdm : Generated EB Tresos config file in .xdm format
┃ ┃ ┃ ┃ ┣ 📜Dem.xdm
┃ ┃ ┃ ┃ ┣ 📜EcuM.xdm
┃ ┃ ┃ ┃ ┣ 📜Mcu.xdm
┃ ┃ ┃ ┃ ┗ 📜Os.xdm
┃ ┃ ┃ ┣ 📂F29H85x
┃ ┃ ┃ ┃ ┣ 📂CCS
┃ ┃ ┃ ┃ ┃ ┗ 📜Cdd_Dma_Example_Mem_Transfer.projectspec
┃ ┃ ┃ ┃ ┗ 📂Cdd_Dma_Example_Mem_Transfer_Config
┃ ┃ ┃ ┃ ┣ 📂config
┃ ┃ ┃ ┃ ┃ ┣ 📜Port.xdm
┃ ┃ ┃ ┃ ┃ ┗ 📜ResourceAllocator.xdm
┃ ┃ ┃ ┃ ┣ 📂output
┃ ┃ ┃ ┃ ┃ ┣ 📂include
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_Cfg.h : Contains the generated pre-compiler configuration header
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_Cbk.h : Contains callback function declarations
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Dem_Cfg.h
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜EcuM_Cfg.h
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Mcu_Cfg.h
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Os_Cfg.h
┃ ┃ ┃ ┃ ┃ ┃ ┗ 📜Port_Cfg.h
┃ ┃ ┃ ┃ ┃ ┣ 📂src
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_Cfg.c : Contains the generated pre-compiler configuration source
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Dem_Cfg.c
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜EcuM_Cfg.c
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Mcu_PBcfg.c
┃ ┃ ┃ ┃ ┃ ┃ ┣ 📜Os_Cfg.c
┃ ┃ ┃ ┃ ┃ ┃ ┗ 📜Port_PBcfg.c
┃ ┃ ┃ ┃ ┃ ┗ 📂swcd
┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_BSWMD.arxml
┃ ┃ ┃ ┃ ┃ ┣ 📜Mcu_BSWMD.arxml
┃ ┃ ┃ ┃ ┃ ┗ 📜Port_BSWMD.arxml
┃ ┃ ┃ ┃ ┗ 📜CMakeLists.txt
┃ ┃ ┃ ┣ 📜CMakeLists.txt
┃ ┃ ┃ ┗ 📜Cdd_Dma_Example_Mem_Transfer.c : Example application for Cdd_Dma memory transfer
┃ ┃ ┗ 📂Cdd_Dma_Example_Mem_Transfer_Mpu
┃ ┃ ┣ 📂Common
┃ ┃ ┃ ┗ 📂tresos
┃ ┃ ┃ ┗ 📂config
┃ ┃ ┃ ┣ 📜Cdd_Dma.xdm : Generated EB Tresos config file in .xdm format
┃ ┃ ┃ ┣ 📜Dem.xdm
┃ ┃ ┃ ┣ 📜EcuM.xdm
┃ ┃ ┃ ┣ 📜Mcu.xdm
┃ ┃ ┃ ┗ 📜Os.xdm
┃ ┃ ┣ 📂F29H85x
┃ ┃ ┃ ┣ 📂CCS
┃ ┃ ┃ ┃ ┗ 📜Cdd_Dma_Example_Mem_Transfer_Mpu.projectspec
┃ ┃ ┃ ┗ 📂Cdd_Dma_Example_Mem_Transfer_Mpu_Config
┃ ┃ ┃ ┣ 📂config
┃ ┃ ┃ ┃ ┣ 📜Port.xdm
┃ ┃ ┃ ┃ ┗ 📜ResourceAllocator.xdm
┃ ┃ ┃ ┣ 📂output
┃ ┃ ┃ ┃ ┣ 📂include
┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_Cfg.h : Contains the generated pre-compiler configuration header
┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_Cbk.h : Contains callback function declarations
┃ ┃ ┃ ┃ ┃ ┣ 📜Dem_Cfg.h
┃ ┃ ┃ ┃ ┃ ┣ 📜EcuM_Cfg.h
┃ ┃ ┃ ┃ ┃ ┣ 📜Mcu_Cfg.h
┃ ┃ ┃ ┃ ┃ ┣ 📜Os_Cfg.h
┃ ┃ ┃ ┃ ┃ ┗ 📜Port_Cfg.h
┃ ┃ ┃ ┃ ┣ 📂src
┃ ┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_Cfg.c : Contains the generated pre-compiler configuration source
┃ ┃ ┃ ┃ ┃ ┣ 📜Dem_Cfg.c
┃ ┃ ┃ ┃ ┃ ┣ 📜EcuM_Cfg.c
┃ ┃ ┃ ┃ ┃ ┣ 📜Mcu_PBcfg.c
┃ ┃ ┃ ┃ ┃ ┣ 📜Os_Cfg.c
┃ ┃ ┃ ┃ ┃ ┗ 📜Port_PBcfg.c
┃ ┃ ┃ ┃ ┗ 📂swcd
┃ ┃ ┃ ┃ ┣ 📜Cdd_Dma_BSWMD.arxml
┃ ┃ ┃ ┃ ┣ 📜Mcu_BSWMD.arxml
┃ ┃ ┃ ┃ ┗ 📜Port_BSWMD.arxml
┃ ┃ ┃ ┗ 📜CMakeLists.txt
┃ ┃ ┣ 📜CMakeLists.txt
┃ ┃ ┗ 📜Cdd_Dma_Example_Mem_Transfer_Mpu.c : Example application for Cdd_Dma with MPU
┃ ┣ 📂Cdd_Ecap
┃ ┣ 📂Cdd_I2c
┃ ┣ 📂Cdd_Ipc
┃ ┣ 📂Cdd_Pwm
┃ ┣ 📂Cdd_Sent
┃ ┣ 📂Cdd_Uart
┃ ┣ 📂Cdd_Xbar
┃ ┣ 📂DeviceSupport
┃ ┣ 📂Dio
┃ ┣ 📂Empty_Projects
┃ ┣ 📂Fls
┃ ┣ 📂Fls_Fapi
┃ ┣ 📂Gpt
┃ ┣ 📂Lin
┃ ┣ 📂Mcu
┃ ┣ 📂Port
┃ ┣ 📂Rtdma
┃ ┣ 📂Spi
┃ ┣ 📂Wdg
┃ ┗ 📜CMakeLists.txt
┣ 📂plugins
┗ 📜CMakeLists.txt
┗ 📜CMakePresets.json