We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 54785

LogiCORE IP Tri-Mode Ethernet MAC v5.5 and earlier - IFG Adjust values that are smaller than 9 will result in TX IFG of 12 when core is generated with half duplex support


The Tri-Mode Ethernet MAC Product Guide documents that the TX inter-frame gap (IFG) Adjust can go as low as 8 bytes when the core has been generated with half-duplex support, but half-duplex is not enabled. 

In the v5.x and v4.x Tri-Mode Ethernet MAC core, a value of 8 will result in a minimum IFG of 12 bytes out of the transmitter. 

An IFG Adjust value of 9 bytes can be used to set the minimum TX IFG to 9 bytes. 

This issue does not apply to cores generated with only full duplex support.


In v6.0 of the Tri-Mode Ethernet MAC core, to be released in Vivado 2013.1, the TX IFG can now be successfully set to 8 bytes.

This is done using the IFG Adjust value when the core has half duplex disabled, but was generated with half duplex support included in the core.
AR# 54785
Date Created 03/06/2013
Last Updated 09/22/2014
Status Active
Type General Article
  • Tri-Mode Ethernet MAC