Control PWM Output Using POEG Triggers on Renesas RA Microcontrollers

R2026b

This example uses:

Open Live Script

This example shows how to use the POEG (Port Output Enable for GPT) feature in the Embedded Coder® Support Package for Renesas® RA Microcontrollers to control PWM output using both software and hardware triggers.

The example demonstrates how POEG disables and re-enables PWM output based on:

  • Software control signals.

  • External hardware trigger input.

A PWM signal generated by the GPT peripheral drives an onboard LED. When the PWM output is enabled, the LED varies in intensity based on the duty cycle. When a POEG trigger occurs, the PWM output is disabled and the LED turns off. Re-enabling the PWM output restores the LED output.

Prerequisites

Before you begin,

Hardware Connection

Use a jumper wire to route the configured PWM output pin to the GPIO pin that drives the onboard LED, if required by your board configuration.

When using an FTDI adapter for communication between the host computer and the Renesas RA6T2 target board, make the following connections.

The Rx, Tx, and GND labels shown in red in the figure indicate the corresponding pins on the FTDI connector.

RASC Project File

This example uses a Renesas Smart Configurator (RASC) project file to define the hardware and peripheral configuration required for PWM generation and POEG control.

The RASC project file configures the following components:

  • Target hardware: RA6T2 microcontroller on the RA6T2-MCK board (Cortex®-M33 core)

  • Flexible Software Package (FSP): Version 6.3.0 for peripheral drivers and board support

  • GPT timer configuration

    • Configured in symmetric PWM mode

    • Generates the PWM signal used to drive the LED

    • Linked to a POEG channel for output disable control

    • Configured with output disable settings to safely control GTIOC pins during POEG events

  • POEG configuration

    • Configured to monitor a hardware trigger input pin

    • Disables GPT PWM output when a trigger event occurs

    • Supports software re-enabling of PWM output

  • Pin configuration

    • Use a jumper wire to route the PWM output pin PB04 to LED2 (PD02) on the 1st Inverter Board Connector (CN5).

    • When using Hardware Trigger model, connect POEG trigger input PA12 (GTETRGB) to GPIO output PB15.

    • GPIO and peripheral pin modes configured through the pin configuration file

  • Clock configuration

    • PLL-based system clock setup

    • GPT peripheral clock sourced from PLL

  • Peripheral drivers

    • GPT (General PWM Timer)

    • POEG (Port Output Enable for GPT)

    • IOPORT (pin configuration)

    • UART (for external mode communication)

The RASC project file ensures that the GPT and POEG modules are correctly configured and linked. These settings ensure that the PWM and POEG modules work together to control PWM output during trigger events.

Models

This example uses two Simulink® models:

  • POEGSoftwareTrigger.slx — Demonstrates software-triggered POEG control

  • POEGHardwareTrigger.slx — Demonstrates hardware-triggered POEG control.

Run the Software Trigger Example

This model demonstrates how to:

  • Disable PWM output using a software stop signal.

  • Re-enable PWM output using a software start signal.

1. Open the POEGSoftwareTrigger.slx Simulink model.

modelName = "POEGSoftwareTrigger";
open_system(modelName)

The model is pre-configured for Renesas RA6 Based hardware.

2. Ensure the following settings are applied:

  • configuration.xml is added as the Renesas Smart Configurator (RASC) project file in Build options. To verify click Modeling > Model Settings to open the Configuration Parameters dialog box. Navigate to Hardware Implementation > Target hardware resources > Build options.

    • Click Code Generation > Optimization and ensure Default parameter behavior parameter is set to Tunable.

      The example model has these default signal values:

      • Start PWM signal = 0

      • Stop PWM signal = 0

        Enable parameter tuning in External mode.

        In the Simulink model, click the Hardware tab and select Monitor & Tune. This allows you to update signal values during executio

        3. Run the model in External mode.

        • In the Simulink model, click Hardware tab and then click Monitor & Tune.

          Observe that:

          • The LED glows with varying intensity (PWM output active).

            4. Set the Stop Signal to 1.

            • The POEG disables the PWM output.

            • The LED turns off.

              3. Set the Stop Signal back to 0.

              4. Set the Start Signal to 1.

              • The POEG clears the disable condition.

              • The PWM output resumes.

              • The LED glows again.

                Run the Hardware Trigger Simulink Model

                1. Open the POEGHardwareTrigger.slx Simulink model.

                modelName = "POEGHardwareTrigger";
open_system(modelName)

                The model is pre-configured for Renesas RA6 Based hardware.

                2. Ensure the following settings are applied:

                • configuration.xml is added as the Renesas Smart Configurator (RASC) project file in Build options. To verify click Modeling > Model Settings to open the Configuration Parameters dialog box. Navigate to Hardware Implementation > Target hardware resources > Build options.

                • Click Code Generation > Optimization and ensure Default parameter behavior parameter is set to Tunable.

                  3. Ensure the default signal values:

                  • Start Signal = 0

                  • GPIO State = 0

                    4. Run the model in External mode.

                    • In the Simulink model, click Hardware tab and then click Monitor & Tune.

                      Observe that the LED glows with varying intensity, indicating that PWM output is active.

                      4. Set the GPIO State to 1.The hardware trigger activates POEG, disables the PWM output, and turns off the LED.

                      5. Set the GPIO Signal back to 0.

                      6. Set the Start Signal to 1.The POEG block clears the disable condition, and the PWM output resumes. The LED glows again.

                      Other Things to Try

                      • Change the duty cycle input to observe how LED brightness varies when PWM output is enabled.

                      • Configure the POEG trigger polarity in the model or RASC file and observe how it affects the disable behavior.