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Avalon-ST interface with the TSE -> how to detect the interrupted transmission

Honored Contributor II

Hi All, 


I'm designing the Custom IP that communicates directly with the TSE Core via the Avalon-ST interface. I couldn't find information *how to detect* that the transmission has been suddenly broken (e.g. by disconnected fiber, etc.). As far as I understand from the TSE Guide the following should happen (bold signal names used below are from the Avalon-ST interface): 


1. error[4] is set (Table 6-7 - "Corrupted receive frame caused by a PHY error. The PHY has asserted an error on the receive GMII.")  

2. endofpacket - **is not set** -> because transmission has been "physically" interrupted, so the 'endofpacket' indicator (sequences: '/T/ /R/ /R/' or '/T/ /R/') had no chance to be sent ?? 

3. valid signal deasserted (???) -> because there is no new valid data ??? 

4. Anything else that I'm missing ???? 


I know that besides that the link should be signaled as 'down', but this information is *not available* on the Avalon-ST interface. Getting data from the Avalon-MM registers is also not an option. 


The question is: how to detect the suddenly broken transmission in order to prevent the hardware to be deadlocked waiting for the new data (...and 'endofpacket') that never comes? Is there any way to do this other than using some kind of timeout mechanism ? 


Any help or suggestions? 



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