# Ethernet VVC TXEN Bug

**URL:** <https://forum.uvvm.org/t/ethernet-vvc-txen-bug/282>\
**Category:** Bitvis VIP Ethernet\
**Tags:** gmii\
**Created:** [March 31, 2022, 8:30am UTC](https://forum.uvvm.org/t/ethernet-vvc-txen-bug/282 "2022-03-31T08:30:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![fmlkc](https://avatars.discourse-cdn.com/v4/letter/f/9d8465/32.png) [@fmlkc](https://forum.uvvm.org/u/fmlkc)\
**Post date:** [March 31, 2022, 8:30am UTC](https://forum.uvvm.org/t/ethernet-vvc-txen-bug/282/1 "2022-03-31T08:30:14Z")

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Hi there,

I use ethernet vvc with gmii phy interface. When I transmit ethernet packet to my DUT(Xilinx Core TEMACv9.0), my packet is marked as bad frame due to txen signal’s falling. TXEN should be high during transfer. But VVC falls TXEN after sending any field in ethernet frame as you see on the image.

 ![Capture](https://europe1.discourse-cdn.com/flex017/uploads/uvvm/original/1X/45f80ead1100a0f5c37d19425295a18ef4102729.png)

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**Author:** ![Erick](https://avatars.discourse-cdn.com/v4/letter/e/bbce88/32.png) [@Erick](https://forum.uvvm.org/u/Erick)\
**Post date:** [April 6, 2022, 11:28am UTC](https://forum.uvvm.org/t/ethernet-vvc-txen-bug/282/2 "2022-04-06T11:28:12Z")

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Hi,

Yes, there should be some signalling from the Ethernet to the GMII so that it doesn’t lower the TXEN between field transfers. I will create a ticket for this issue so it is fixed in the next release.

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**Author:** ![fmlkc](https://avatars.discourse-cdn.com/v4/letter/f/9d8465/32.png) [@fmlkc](https://forum.uvvm.org/u/fmlkc)\
**Post date:** [April 6, 2022, 1:59pm UTC](https://forum.uvvm.org/t/ethernet-vvc-txen-bug/282/3 "2022-04-06T13:59:04Z")

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Hi Erick,

Thanks,

Rgrds