Hello TI Team,
we are using the DP83869HM in both revisions Rev.1 and Rev. 3 in media conversion mode between copper and fiber.
In the first application, DP83869HM Rev. 1 according to the datasheet “SNLS614A – December 2018” is used.
In the second application, DP83869HM Rev. 3 according to the datasheet “SNLS614B – December 2022” is used.
In application (1), the PHY Identifier Register #2 reads A0F1h.
In application (2), the PHY Identifier Register #2 reads A0F3h.
The DP83869HM´s are connected on one side to a switch engine (copper side) and on the other side to an optical transceiver (fiber side). For Link (LNK) and Activity (ACT) status indication on the fiber side, we use two LEDs (LNK is connected to pin 46 and ACT is connected to pin 45) in active LOW mode. Both LEDs are configured accordingly correctly in register LEDS_CFG1 and LEDS_CFG2.
We have detected a deviation between the both DP83869HM versions in the same use case.
When no fiber optical cable is plugged at the destination port (transmitting Ethernet frames) and the operation starts:
- In application (1), the LED ACT is flashing 8 times and remains OFF permanently.
- In application (2), the LED ACT is flashing permanently.
Only after connection and disconnection of the fiber optical cable, the ACT LED remains OFF permanently as in application (1).
The registers read the following values, when no fiber optical cable is plugged:
Basic Mode Status Register (1h): 7949h
MC_LINK_LOSS (1ECh): 1FFCh
Fiber Status Register: 6149h
Is there any configuration for DP83869HM Rev. 3 to have the same behavior (what is normally expected) shown on DP83869HM Rev. 1?
Best regards,
Andreas
