DP83867IR: Not communicating

PRAHLAD Supeda

Part Number: DP83867IR

Customer is using DP83867IR PHY & is not responding to the read operation. They monitored the MDIO on the CRO for assuring the transmission of commands. Have also looped in customer for direct interaction over e2e.

MDC & MDIO Capture:

over 6 years ago

0 Vibhu Vanjari over 6 years ago

TI__Genius 11900 points

Hello Prahlad,

Can you confirm the following:

No other pull-up resistors on the MDIO net on any other places of the board.
RBIAS pin resistor tolerance is 1%
All voltages meet the requirements in "7.3 Recommended Operating Conditions"
"7.6 Power-Up Timing" and "7.7 Reset Timing" are met in the design

Thanks,

Vibhu

0 PRAHLAD Supeda over 6 years ago in reply to Vibhu Vanjari

TI__Expert 6190 points

Hi Vibhu,

Here are the comments from customer:

1. Only one pullup is used for mdio pin as shown in schematic.

2. R bias is 1% tolerance. I can see 1V across rbias.

3. All the supplies are in operating range.

4. Yes, Timings are taken care.

0 Vibhu Vanjari over 6 years ago in reply to PRAHLAD Supeda

TI__Genius 11900 points

Hello Prahlad,

Was this MDIO / MDC capture taken after PHY RESET? Since timing is taken care of, I assume sufficient time was allowed before trying to access registers.

Based on the schematic it looks like you are using 1.8 V VDDIO, is this correct?

If so, the voltage swing on MDIO and MDC seem to be violating the "7.1 Absolute Maximum Ratings" table.

Thanks,

Vibhu

0 Vibhu Vanjari over 6 years ago in reply to Vibhu Vanjari

TI__Genius 11900 points

Hello Prahlad,

What is the status of this issue?

Thanks,

Vibhu

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DP83867IR: Not communicating