TMS320F28388D: LINKACT effective power level

Hi Brian,

I think it's active low based on the Beckhoff datasheet (here) and the ControlCard schematic design, i.e. No Link = HIGH state where LED is OFF. I will double confirm however and review how this can be better documented.

Best,

Kevin

Hi Kevin,

Thanks for your kindly supply.

Currently the observation of customer is as below: 

Could you help to check whether this is aligned with the normal situation? And where we could find the official definition of GPIO behavior? We looked through several different materials but not able to find any details.

Thanks,

Brian

Hi Brian, 

The Green Light (GPIO143) behavior seems to match the LINKACT behavior from the Beckhoff datasheet, except I would have expected it to blink when there's both Link and Activity existing. Not certain why this differs right now.

The Yellow Light (GPIO148) acts as an input from the C2000 perspective. I don't believe Beckhoff defines requirements for this LED. We connect it to LED_0 output from the PHY on the ControlCard design, below is from DP83822 datasheet. Seems like Mode 2 may be configured.

One thing I noticed in our C2000WARE EtherCAT examples is that we configure GPIO143 and GPIO144 as invert polarity. I suppose this is done to match the LED circuit (active low).

    //
    // P0 Linkstatus and Link Active LED
    //
    GPIO_setPinConfig(GPIO_148_ESC_PHY0_LINKSTATUS);
    GPIO_setPadConfig(148, GPIO_PIN_TYPE_STD);
    GPIO_setPinConfig(GPIO_143_ESC_LED_LINK0_ACTIVE);
    GPIO_setQualificationMode(143, GPIO_QUAL_ASYNC);
    GPIO_setPadConfig(143, GPIO_PIN_TYPE_INVERT);

Best,

Kevin