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PRU-ICSS-INDUSTRIAL-SW: EtherCAT Link/Activity LED and RXLINK signal

Patrick Ruf
Genius 4770 points
Part Number: PRU-ICSS-INDUSTRIAL-SW
Other Parts Discussed in Thread: TIDA-00299, AMIC110, TLK105, TLK110

Hi,

Is it possible that someone from TI clarify how to correctly connect Link/Activity LED and RXLINK (e.g. PR0_MII0_RXLINK) for the newest EtherCAT Firmware?

I have seen a lot of schematics with different approach. But I'm shure there is "best of" solution when using DP83822 PHY. E.g. TIDA-00299 schematic has no more connection from PHY's to the RXLINK signal in the PRU's (as far as I can see). Also from my point of view the DP83822 PHY is able to create the Link/Activity LED signal as needed by the EtherCAT Indicator ans Labeling Specification.

But what about Enhanced Link detection?
When I look into the PRU-ICSS EtherCAT Firmware API Guide (Wiki) I can see that a connection to the RXLINK (e.g. PR0_MII0_RXLINK) signals is still needed (recommended) for Enhanced Link detection.
If the Link LED signal from PHY needs to be used for RXLINK signal than one have to manually create the signal for the Link/Activity LED (e.g. by the EtherCAT application or stack)? Or is this done by some of the PRU GPIO's and the PRU firmware?

As you can see there is a lot of confusion about this.

Thanks and best regards,
Patrick

  • 0
    TI__Guru**** 393215 points
    The RTOS team have been notified. They will respond here.
  • 0 in reply to Biser Gatchev-XID
    TI__Expert 7570 points
    Patrick

    The AMIC110 (AM335x variant) uses the DP83822.
    The schematic for the AMIC110 ICE is available on www.ti.com/.../tmdxice110

    The DP83822 Pin 24 Mode 2: SPEED Indication, LED indicates the speed of the link. If speed is 100 Mbps, LED is ON. If speed is 10 Mbps, LED is OFF.
    This signal is input into
    Pin V1 - configured as PR1_MII0_RXLINK
    Pin U18 - configured as PR1_MII1_RXLINK

    David
  • 0 in reply to David Zaucha
    Genius 4770 points
    David,

    Thanks. I'm shure it should be V2 (PR1_MII0_RXLINK) as V1 is VSS. So this assumes that Speed LED is reacting as fast as Link LED signal in the DP83822 (Figure 27 in DP83822 datasheet) (?).
    That also means that the Link/Activity LED (as mandatory by the EtherCAT Indicator specification) is directly controlled be the DP83822 LED_0 signal (Pin 17, Mode 2). Correct?

    So this behaviour could have been done also with the TLK110 or TLK105 but has been done differently in early versions of the AM335x ICE board (e.g. Revision <2.1a).

    Best regards,
    Patrick
  • 0 in reply to Patrick Ruf
    TI__Expert 7570 points
    Hi Patrick

    There is a TI design which has some additional information.
    It is available at www.ti.com/.../TIDA-00299

    > So this assumes that Speed LED is reacting as fast as Link LED signal in the DP83822 (Figure 27 in DP83822 datasheet) (?).
    I will try to link one of our Phy experts in of this thread to answer this.

    > That also means that the Link/Activity LED (as mandatory by the EtherCAT Indicator specification) is directly controlled be the DP83822 LED_0 signal (Pin 17, Mode 2). Correct?
    LED0 is driven by DP83822 pin 17

    > So this behaviour could have been done also with the TLK110 or TLK105 but has been done differently in early versions of the AM335x ICE board (e.g. Revision <2.1a).
    Let me investigate this.

    David
  • 0 in reply to David Zaucha
    TI__Expert 7570 points
    Hi Patrick

    We should hear from the phy team shortly.

    Thank you, the AMIC110 input was V2 not V1.

    AM335x ICE V2.1 changed to use LED_speed Pin 27 on the TLK110

    David
  • 0 in reply to David Zaucha
    TI__Expert 7570 points
    Hi Patrick

    We got some feedback from the Phy team.
    There is Fast Link Drop and then Enhanced Link Detection.
    The DP83822 supports FLD. This means ELD is not required.
    ELD observes error on the RX_ER pin to determine a link is poor and manually kills the link by writing a command to the PHY.
    FLD is controlled by the PHY. When the PHY experiences a number of different issues, it will kill the link in under 10uS when enabled.

    For EtherCAT there is also LED requirement that you have an LED for Link and Speed/Act.

    David