DP83848K: DP83848K Ethernet cable is not detected question

Eric Zheng

Part Number: DP83848K

Dear Team:

DP83848K has two states of communication and non-communication in the same PCB design. Failure DP83848K register value display is not connected. Attached IC schematic diagram design.

Please help to confirm whether there is a parameter setting problem.

Thanks!

DP83848_sch.pdf

over 6 years ago

0 Ross Pimentel over 6 years ago

TI__Mastermind 23675 points

Hi Eric,

Please describe in more detail what you are observing.
I unfortunately do not follow what you mean by 2 communication states and 2 non-communication states.

0 Eric Zheng over 6 years ago in reply to Ross Pimentel

Prodigy 200 points

Dear Ross：

Thanks for reply！

The problem is described as follows:

Non-communication means DP83848 is unable to connect PC Ethernet .The IMX6S chip read DP83848 PHY address is 0x01, the DP83848K power on have worked normal, but reading the MII_BSR register address 0x7849 is error. The DP83848k can't software handshaking.

Is there any problem with the schematic design of the attached hardware?If there is no problem, is there a good way to solve the problem?

Thanks！

0 Eric Zheng over 6 years ago in reply to Eric Zheng

Prodigy 200 points

Dear Ross：

DP83848K read PHY address is normal in RMII mode，but auto-negotiation simply can't be done.

The snla076a.pdf explain TXD[3:2] should be pull low 2.2k resister.Does it matter?

Thanks!

0 Ross Pimentel over 6 years ago in reply to Eric Zheng

TI__Mastermind 23675 points

Hi Eric,

Please provide a register dump from 0x0 to 0x1F.

Is it possible for you to have a look at the link pulses with an Oscope using a 100 ohm termination on the MDI?

0 Eric Zheng over 6 years ago in reply to Ross Pimentel

Prodigy 200 points

Dear Ross：

I have check customer PCB layout ，testing find DP83848K Pin37 RXD_1 trace open circuit, The revised design driver add normal.

Thanks very much!

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DP83848K: DP83848K Ethernet cable is not detected question