3.7.2.1. PRU Getting Started Labs

3.7.2.1.1. Introduction

The PRU Getting Started Labs demonstrate:

  1. How to create a PRU project in Code Composer Studio (CCS), or from the Linux terminal

  2. How to write PRU firmware in C, assembly, or mixed C and assembly

  3. How to compile PRU firmware from CCS, or from the Linux terminal

    • CCS shows how to compile binaries that can be loaded by CCS, another core running Linux, or another core running RTOS or NORTOS (NORTOS is also known as “bare metal” or “no OS”)

    • Linux terminal shows how to compile binaries that can be loaded by another core running Linux

  4. How to initialize the PRU from CCS, or another core running Linux

  5. How to debug the PRU from CCS, or another core running Linux

Note

These labs reference the Processor SDK and MCU+ SDK documentation. To find the SDK documentation:

  1. Go to the processor’s product page. (AM64x example: https://www.ti.com/product/AM6442)

  2. Go to section “Design & Development” -> “Software development” -> “MCU-PLUS-SDK” or “PROCESSOR-SDK-LINUX”.

  3. Select “Download options” -> “Documentation”. Click the link to the latest SDK documentation. (AM64x example for MCU+ SDK 8.2: https://software-dl.ti.com/mcu-plus-sdk/esd/AM64X/08_05_00_24/exports/docs/api_guide_am64x/index.html)

  4. If using an SDK that is not the latest SDK, it is suggested to use that release’s SDK documentation instead of the latest SDK documentation.

Note

This lab documentation is under active development. It will be updated between SDK releases. If there are any questions, please reach out on the TI e2e forums.

Note

Steps to initialize the PRU from another core running an OS from an MCU+ SDK (i.e., RTOS or NORTOS) will be added at a later time. Not all cores running RTOS or NORTOS can initialize the PRU. Reference the MCU+ SDK release notes to see which cores support initializing the PRU with the PRUICSS driver.

Note

These labs do not cover cores running an OS from a Processor SDK RTOS (i.e., TI-RTOS). Steps to initialize the PRU from a core running TI-RTOS are provided as a resource for customers using AM335x, AM437x, and AM57xx. However, the TI-RTOS steps have not been tested. See Last Tested Configuration for more information.

Note

Steps to debug the PRU from a core running an OS from an MCU+ SDK (i.e., RTOS or NORTOS) will be added at a later time.

3.7.2.1.1.1. Supported Processors

  • PRU-ICSS processors: AM335x, AM437x, AM57xx

  • PRU-SS processors: AM62x

  • PRU_ICSSG processors: AM64x, AM65x

3.7.2.1.1.2. Required Hardware and Software

The following hardware and software are required to complete the PRU Getting Started Labs:

Hardware

  • EVM board: Any TI EVM for a supported processor, or BeagleBone Black

  • Power supply for the board

  • Debug connector: JTAG emulator, FTDI cable, or micro USB cable for UART port depending on the board. Some EVMs have an onboard debugger, while some EVMs require a separate JTAG emulator

  • Computer running Linux or Windows

Software

  • A Processor SDK for the processor. Install the Linux or MCU+ Processor SDK as appropriate.

  • The PRU Software Support Package (PSSP)

    • The PSSP is included in the example-applications/pru-icss-x.y.z/ folder of many Linux Processor SDK releases.

    • If using an MCU+ SDK, a Linux SDK without the PSSP installed, or if running Windows on the computer, download the PSSP from the git repository here. The notation <PSSP_PATH> will be used throughout the labs to reference the PSSP installation location.

  • Code Composer Studio (CCS)

  • PRU Code Generation Tools (also available through the CCS App Center)

Note

If using a Linux Processor SDK, check which version of the PSSP is used:

  • SDK 7.x (Linux kernel 5.4): compatible with PSSP tags v5.7.0 - v5.9.0

  • SDK 8.x (Linux kernel 5.10): compatible with PSSP tags v6.0.0 onwards

If using the PSSP packaged within the Linux Processor SDK, x.y.z in the folder name is the version number. e.g., ‘example-applications/pru-icss-6.0.1/’ uses tag v6.0.1. The tag can also be viewed in the PSSP files ReadMe.txt and Release_Notes.txt.

3.7.2.1.1.3. Last Tested Configuration

The PRU Getting Started Labs were last tested with:

  • CCSv11.2

  • AM335x Processor SDK Linux 7.3 with BeagleBone Black

  • AM62x Processor SDK Linux 8.3 with AM62x SK EVM

  • AM64x Processor SDK Linux 8.1 with AM64x General Purpose EVM

Note

These labs do not cover cores running an OS from a Processor SDK RTOS (i.e., TI-RTOS running on AM335x, AM437x, AM57xx, AM65x). Some legacy information is provided for initializing the PRU from TI-RTOS cores on AM335x, AM437x, and AM57xx. This information was written using PROCESSOR-SDK-RTOS 6.3. However, this information has not been tested or validated in several years. These sections are not supported by TI, and are marked legacy.

TI no longer provides support for TI-RTOS / baremetal SW development for AM335x & AM437x. See this notice for more information.