• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 1735 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.

Ethernet PHY DP83848IVV Supports Jumbo Frames in MII Mode?

MAGALINGAM NATARAJAN
Prodigy 150 points

Hi,

Can you please clarify, whether DP83848IVV PHY will support Jumbo Frame in MII mode or not?


I have read the data sheet in DP83848IVV. RMII mode supports Jumbo Frames. But, i want to use Jumbo frames in MII mode.

If not, please suggest the other  right PHY device from TI.

Magalingam

  • 0
    TI__Mastermind 31600 points
    Magalingam,

    The key aspect of receiving frames longer than the IEEE specified length of 1518 bytes (including CRC) is the 100Base-TX descrambler timeout. The descrambler timeout must be increased by setting bit 7 (DESC_TIME) of the 100 Mb/s PCS Configuration and Status Register (PCSR), address 0x16h. When the descrambler timeout is increased, the DP83848 can receive larger packets. This setting is required for reception of longer packets in both MII mode and RMII mode.

    Patrick
  • 0 in reply to Patrick OFarrell
    Prodigy 150 points

    Hi,

    We have seen the data sheet for DESC_TIME register settings. If it is "0" what will be maximum packet size and if it is "1" what will be supported packet size?

    Whether the PHY device will support both Transmit and Receive Packets >9K.



    Magalingam

  • 0 in reply to MAGALINGAM NATARAJAN
    TI__Mastermind 31600 points
    Magalingam,

    I am not aware of a maximum packet size on the transmit length. Regarding the maximum packet size on the receive length, the PHY can receive packets of 9k bytes with the default value of 0x0 for the DESC_TIME register setting. With the value of 0x1 for the DESC_TIME register setting, the PHY can receive packets of 25k bytes.

    Patrick