Feedback

EasyDMA

While the event system allows for peripherals to interact with each other autonomously without the CPU, Easy Direct Access Memory (EasyDMA) is implemented by a number of peripherals on the nRF54L Series to provide direct access to RAM. EasyDMA is intended to enable peripherals to interact directly with system memory (RAM) as a bus manager, without requiring intervention from the CPU. This function facilitates efficient data transfers, reduces real-time processing demands on the CPU, and enhances both system performance and power efficiency. It is important to note that EasyDMA cannot access non-volatile memory.

This concept is illustrated in the following example figure, where READER is reading data from RAMc, while WRITER is writing data to RAMa and RAMb (each RAM being separate bus subordinates).

RAM on the nRF54L Series

The RAM on the nRF54L Series is divided into regions (RAM00, RAM01), with each region further divided into sections. This structure reduces latency when both the Arm CPU and FLPR are running and also supports flexible power management, enhancing power efficiency, as demonstrated in Lesson 5, where we explore memory retention across various sleep modes. Each section has a separate power and retention control for the System ON and System OFF modes. This functionality allows for managing RAM content during sleep modes and powering down unused sections to save energy.

Note

If the FLPR is used, RAM01 should be reserved for FLPR code and data, as well as non-time-critical application data. RAM00 should be used for time-critical data, such as EasyDMA buffers and application data accessed by low-latency ISRs.

nRF54LM20A | nRF54LM20B
nRF54L15 | nRF54L10 | nRF54L05
nRF54LV10A
nRF54LS05A | nRF54LS05B

nRF54LM20A | nRF54LM20B

nRF54L15 | nRF54L10 | nRF54L05

nRF54LV10A

nRF54LS05A | nRF54LS05

EasyDMA Channels and Buffers

There are several peripherals on the nRF54L Series that handle large amount of data use EasyDMA for efficient data handling. These include Serial Communication Interfaces, the Radio, Cryptographic accelerators, Analog (SAADC), and PWM.

Some peripherals are designed with multiple EasyDMA instances to provide dedicated channels, such as separate channels for reading and writing data. Data transfers are configured using pointer (.PTR) and maximum count (.MAXCNT) registers. The .PTR register specifies the start address of the RAM buffer, and .MAXCNT defines the maximum number of bytes to transfer.

Some peripherals are equipped with the following functionalities:

Double-Buffering: For some peripherals, the .PTR and .MAXCNT registers are double-buffered in hardware. This allows software to update these registers for the next transfer immediately after the current one has started (for example, after a STARTED event), preparing for a continuous stream of operations without interruption.
Array List Mode: Some peripherals support EasyDMA in an Array List mode for channels with a LIST register. In this mode, data is handled as a linear array in RAM, with items stored sequentially. For example, the SPIM peripheral uses this feature for both TX and RX in its EasyDMA. This mode allows the hardware to automatically move to the next buffer in the list, eliminating the need to manually configure the .PTR (by software, involving the CPU) for each memory chunk, which is very useful for efficient and continuous data streaming.

Once an EasyDMA transfer is complete, the CPU can read the AMOUNT register to determine the number of bytes successfully transferred. Events like END, STOPPED, READY, or specific DMA-related events (for example, DMA.RX.END, DMA.TX.END) indicate that EasyDMA has finished accessing the RAM.

To learn more about EasyDMA, see the EasyDMA documentation. You can also read the datasheet for each peripheral you are interested in. As different peripherals implement different EasyDMA features based on their needs.

Nordic Developer Academy Privacy Policy

1. Introduction

In this Privacy Policy you will find information on Nordic Semiconductor ASA (“Nordic Semiconductor”) processes your personal data when you use the Nordic Developer Academy.

References to “we” and “us” in this document refers to Nordic Semiconductor.

2. Our processing of personal data when you use the Nordic Developer Academy

2.1 Nordic Developer Academy

Nordic Semiconductor processes personal data in order to provide you with the features and functionality of the Nordic Developer Academy. Creating a user account is optional, but required if you want to track you progress and view your completed courses and obtained certificates. If you choose to create a user account, we will process the following categories of personal data:

Email
Name
Password (encrypted)
Course progression (e.g. which course you have completely or partly completed)
Certificate information, which consists of name of completed course and the validity of the certificate
Course results

During your use of the Nordic Developer Academy, you may also be asked if you want to provide feedback. If you choose to respond to any such surveys, we will also process the personal data in your responses in that survey.

The legal basis for this processing is GDPR article 6 (1) b. The processing is necessary for Nordic Semiconductor to provide the Nordic Developer Academy under the Terms of Service.

2.2 Analytics

If you consent to analytics, Nordic Semiconductor will use Google Analytics to obtain statistics about how the Nordic Developer Academy is used. This includes collecting information on for example what pages are viewed, the duration of the visit, the way in which the pages are maneuvered, what links are clicked, technical information about your equipment. The information is used to learn how Nordic Developer Academy is used and how the user experience can be further developed.

2.2 Newsletter

You can consent to receive newsletters from Nordic from within the Nordic Developer Academy. How your personal data is processed when you sign up for our newsletters is described in the Nordic Semiconductor Privacy Policy.

3. Retention period

We will store your personal data for as long you use the Nordic Developer Academy. If our systems register that you have not used your account for 36 months, your account will be deleted.

4. Additional information

Additional information on how we process personal data can be found in the Nordic Semiconductor Privacy Policy and Cookie Policy.

‍‍

Nordic Developer Academy Terms of Service

1. Introduction

‍These terms and conditions (“Terms of Use”) apply to the use of the Nordic Developer Academy, provided by Nordic Semiconductor ASA, org. nr. 966 011 726, a public limited liability company registered in Norway (“Nordic Semiconductor”). ‍

Nordic Developer Academy allows the user to take technical courses related to Nordic Semiconductor products, software and services, and obtain a certificate certifying completion of these courses. By completing the registration process for the Nordic Developer Academy, you are agreeing to be bound by these Terms of Use.

These Terms of Use are applicable as long as you have a user account giving you access to Nordic Developer Academy.‍

‍2. Access to and use of Nordic Developer Academy

‍‍Upon acceptance of these Terms of Use you are granted a non-exclusive right of access to, and use of Nordic Developer Academy, as it is provided to you at any time. Nordic Semiconductor provides Nordic Developer Academy to you free of charge, subject to the provisions of these Terms of Use and the Nordic Developer Academy Privacy Policy.

To access select features of Nordic Developer Academy, you need to create a user account. You are solely responsible for the security associated with your user account, including always keeping your login details safe.

You will able to receive an electronic certificate from Nordic Developer Academy upon completion of courses. By issuing you such a certificate, Nordic Semiconductor certifies that you have completed the applicable course, but does not provide any further warrants or endorsements for any particular skills or professional qualifications.

Nordic Semiconductor will continuously develop Nordic Developer Academy with new features and functionality, but reserves the right to remove or alter any existing functions without notice.

‍3. Acceptable use

You undertake that you will use Nordic Developer Academy in accordance with applicable law and regulations, and in accordance with these Terms of Use.‍ You must not modify, adapt, or hack Nordic Developer Academy or modify another website so as to falsely imply that it is associated with Nordic Developer Academy, Nordic Semiconductor, or any other Nordic Semiconductor product, software or service.

You agree not to reproduce, duplicate, copy, sell, resell or in any other way exploit any portion of Nordic Developer Academy, use of Nordic Developer Academy, or access to Nordic Developer Academy without the express written permission by Nordic Semiconductor. You must not upload, post, host, or transmit unsolicited email, SMS, or \”spam\” messages.

You are responsible for ensuring that the information you post and the content you share does not;

contain false, misleading or otherwise erroneous information
infringe someone else’s copyrights or other intellectual property rights
contain sensitive personal data or
contain information that might be received as offensive or insulting.
Such information may be removed without prior notice.

‍Nordic Semiconductor reserves the right to at any time determine whether a use of Nordic Developer Academy is in violation of its requirements for acceptable use.

Violation of the at any time applicable requirements for acceptable use may result in termination of your account. We will take reasonable steps to notify you and state the reason for termination in such cases.

‍4. Routines for planned maintenance

‍Certain types of maintenance may imply a stop or reduction in availability of Nordic Developer Academy. Nordic Semiconductor does not warrant any level of service availability but will provide its best effort to limit the impact of any planned maintenance on the availability of Nordic Developer Academy.

5. Intellectual property rights

‍Nordic Semiconductor retains all rights to all elements of Nordic Developer Academy. This includes, but is not limited to, the concept, design, trademarks, know-how, trade secrets, copyrights and all other intellectual property rights.

Nordic Semiconductor receives all rights to all content uploaded or created in Nordic Developer Academy. You do not receive any license or usage rights to Nordic Developer Academy beyond what is explicitly stated in this Agreement.

‍6. Liability and damages

‍Nothing within these Terms of Use is intended to limit your statutory data privacy rights as a data subject, as described in the Nordic Developer Academy Privacy Policy. ‍You acknowledge that errors might occur from time to time and waive any right to claim for compensation as a result of errors in Nordic Developer Academy. When an error occurs, you shall notify Nordic Semiconductor of the error and provide a description of the error situation.

You agree to indemnify Nordic Semiconductor for any loss, including indirect loss, arising out of or in connection with your use of Nordic Developer Academy or violations of these Terms of Use. ‍Nordic Semiconductor shall not be held liable for, and does not warrant that (i) Nordic Developer Academy will meet your specific requirements, (ii) Nordic Developer Academy will be uninterrupted, timely, secure, or error-free, (iii) the results that may be obtained from the use of Nordic Developer Academy will be accurate or reliable, (iv) the quality of any products, services, information, or other material purchased or obtained by you through Nordic Developer Academy will meet your expectations, or that (v) any errors in Nordic Developer Academy will be corrected.

You accept that this is a service provided to you without any payment and hence you accept that Nordic Semiconductor will not be held responsible, or liable, for any breaches of these Terms of Use or any loss connected to your use of Nordic Developer Academy. Unless otherwise follows from mandatory law, Nordic Semiconductor will not accept any such responsibility or liability.

‍7. Change of terms

‍Nordic Semiconductor may update and change the Terms of Use from time to time. Nordic Semiconductor will seek to notify you about significant changes before such changes come into force and give you a possibility to evaluate the effects of proposed changes. Continued use of Nordic Developer Academy after any such changes shall constitute your acceptance of such changes. You can review the current version of the Terms of Use at any time at https://academy.nordicsemi.com/terms-of-service/

‍8. Transfer of rights

‍Nordic Semiconductor is entitled to transfer its rights and obligation pursuant to these Terms of Use to a third party as part of a merger or acquisition process, or as a result of other organizational changes.

‍9. Third Party Services

‍‍To the extent Nordic Developer Academy facilitates access to services provided by a third party, you agree to comply with the terms governing such third party services. Nordic Semiconductor shall not be held liable for any errors, omissions, inaccuracies, etc. related to such third party services.

‍10. Dispute resolution

‍‍The Terms of Use and any other legally binding agreement between yourself and Nordic Semiconductor shall be subject to Norwegian law and Norwegian courts’ exclusive jurisdiction.

nRF54L Series Express

EasyDMA

Note

EasyDMA Channels and Buffers

Switch language?

Change summary

What's new in the latest version