• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 315 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

National Phy DP83865DVH problem

Muhammad Hassan
Prodigy 10 points
Other Parts Discussed in Thread: DP83865

Hi,

We are using Naitonal PHY DP83865DVH in our design of ethernet systems. We are operating at 1000Mbps wire speed, but there are few problems that we are facing.

 When we connect our system with a PHY of different vendor, at 1000Mbps with minimum IPG/IFG, packets coming back to back, we don't encounter any problem. Link stays stable. Packet flow is normal irrespective of the packet size.

But when we connect our system with the same national phy DP83865DVH, at 1000 Mbps, minimum IPG and minimum packet size of 60 Bytes, we encounter a very serious issue of link disconnections. As soon as the 1000Mbps stream is connected, the link starts to disconnect, reconnects and then disconnects. This goes on and on forever. Can't figure out where the problem might be. We have checked the ethernet cables, we are using cat6 cables. We have also tested it with cat5e cables. Interesting thing is that the link stays stable on bigger packet sizes. For example a packet size of greater than 200, minimum IPG, back to back stream, the link stays stable. But as soon as we decrease the packet size, the link starts to disconnect.

Can anyone point us to what the problem might be? We shall be thankful to you for that.

Regards

  • 0
    TI__Mastermind 31600 points

    Hi,

    Presumably the DP83865 links and remains linked prior to the start of the transmit stream.  In other words, the transmit stream does not begin immediately after the cable is connected.  Could you confirm?

    Is the DP83865 transmitting also or is it only receiving the transmit stream from your system?

    Could you provide a dump of the registers from the DP83865 prior to the start of the transmit stream and during the transmit stream?

    Have you tested other packet sizes between 60 bytes and 200 bytes to determine if the link remains stable?  Is 200 bytes the smallest packet at which the link remains stable or just the smallest packet you have tested with for which the link remains stable?

    Patrick