LP-AM263P: AM263P + DP83822 MII loopback

Frangline

Intellectual 2505 points

Part Number: LP-AM263P
Other Parts Discussed in Thread: DP83822I

Tool/software:

Hi,

We are facing issue with the Ethernet communication in Dp83822i PHY .

Have tried Multiple settings in the PHY registers and have mentioned the status below.

Controller : AM263px

Controller To PHY:

1) MDIO Pins - Read/Write PHY Registers - OK

2) PHY Address detecting - OK

3) When Loop back Mode Enabled , Loopback function is not working (Internal Transmit and receive ) - NOT OK

PHY TO PC:

1) Once, When Loopback Mode Enabled and an ethernet cable connected between PHY to PC, there occurs a packet transmission between

PC to PHY. Which is not the intended behaviour. - NOT OK

2) In normal mode (when Loopback mode is disabled )- Transmit/Receive not working (between PC to PHY) - NOT OK

3) Auto Negotiation (100/ 10mbps half-duplex and 10 mbps Full Duplex) - working (From read status of 0x0005 Register),

but there is no communication between PHY to PC or vice versa. - NOT OK

4) 100Mbps Full duplex Auto negotiation is not Working (its auto negotiating to 100mbps Half duplex only) - NOT OK

over 1 year ago

0 Shaunak Deshpande over 1 year ago

TI__Mastermind 19212 points

Hi Frangline,

I would need a bit more information here.

1. Can the customer provide a dump of the gel script "AM263P_cpsw_mdio_config.gel". Please refer this FAQ on how to use gel files: https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1040141/faq-mcu-plus-sdk-am243x-how-do-i-get-cpsw-diagnostic-statistics-using-debug-gels-in-mcu-sdk-enet-lld (Instead, use the above mentioned GEL file for AM263Px)

2.Has the customer verified the contents of the BMCR and BMSR registers and is it as expected (per their configurations)

3. If I understand correctly, in case of LOOPBACK mode, packets are being transmitted between PC and PHY and incase of normal, the packets are not being transmitted.

Frangline said:
100Mbps Full duplex Auto negotiation is not Working (its auto negotiating to 100mbps Half duplex only) - NOT OK

4. Would it be possible to get some code snippets on how they are configuring the above.

5. Probing MDI link would be useful to verify auto-negotiation pulses are occurring on the line. If there are doubts about MDI terminations, then verifying proper signal levels here would also be useful. In the past, I have seen this to be an issue with a customer integrating a different PHY on AM263Px. This seems to be a custom PHY driver integration, Has the customer got the schematics reviewed from our HW/ PHY team?

Regards,
Shaunak

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LP-AM263P: AM263P + DP83822 MII loopback