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CCS/TMS320F280041: PWM IO 2ms high level signal

Susan Yang
Genius 9955 points
Part Number: TMS320F280041


Tool/software: Code Composer Studio

Dear team

My customer designed their board with TMS320F280041.  ADC, PWM, and other modules could be used normally now.

But they found that the PWM IO signal must had a high level signal of about 2ms as long as the power (5V) was turned on.

They tested the example project epwm_ex2_updown_aq. It also had 2ms high level signal.

boot mode: GPIO32 high, GPIO24 high

Please help.

  • 0
    TI__Guru 52040 points

    At reset, all GPIOs are in high impedance mode. The user can change them to be in GPIO Output mode with LOW state when the device comes out of reset. During the initialization of the ePWM module then can keep the GPIO in the GPIO Output mode with LOW state. When they are ready to enable the ePWM module, they can switch the GPIO to be in driven by the ePWM module. I dont believe there is an issue with the GPIO module, it should be just a matter of initialization sequence.

    Nima

  • 0 in reply to Nima Eskandari
    TI__Genius 9955 points

    Sorry for late reply


    This method had been tested and there still had a high level of about 2ms

    1 config the GPIO FIRST 
    GPIO_setPadConfig(2, GPIO_PIN_TYPE_OD);
    GPIO_setPinConfig(GPIO_2_GPIO2);
    GPIO_setPadConfig(3, GPIO_PIN_TYPE_OD);
    GPIO_setPinConfig(GPIO_3_GPIO3);

    2  When they are ready to enable the ePWM module, they switch the GPIO to be in driven by the ePWM module. 
    GPIO_setPadConfig(2, GPIO_PIN_TYPE_STD);
    GPIO_setPinConfig(GPIO_2_EPWM2A);
    GPIO_setPadConfig(3, GPIO_PIN_TYPE_STD);
    GPIO_setPinConfig(GPIO_3_EPWM2B);

    Please help

  • 0 in reply to Susan Yang
    TI__Guru 52040 points

    Can you try setting the pins to low state at the top of the main?

    I'm assuming another initialization is causing this.