Zynq US+ MDIO critical warnings in timing summary

[baf2099]

I'm using a Zynq US+ part and have implemented an GEM (Gigabit Ethernet Mac) interface using using EMIO. I've enabled the MDIO interface as well. The zynq ip block MDIO signals are routed to a xilinx PCS/PMA Ethernet core for GMII <-> SGMII conversion. After implementation i get 2 critical warnings related to the zynq MDIO connections.

1. a "no_clock" on design_wrapper/design_i/zynq_ultra_ps/inst/PS8_i/EMIOENET1MDIOMDC

2. a "unconstrained_internal_endpoints" (specifically for maximum delay) on design_wrapper/design_i/zynq_ultra_ps/inst/PS8_i/EMIOENET1MDIOI

The zynq ps is the Master of the MDIO inteface and I would expect it to be the provider of whatever constraints are necessary, especially in terms of the clock as I have no control of the rate on the PL side.

Should I just ignore these or what can I do to properly constrain the design?

[wtilton]

I have the same issue.  And if you constrain the path to the fpga pin with -datapath_only:

set_max_delay -datapath_only -from [get_pins {design_1_i/zynq_ultra_ps_e_0/U0/PS8_i/EMIOENET1MDIOTN design_1_i/zynq_ultra_ps_e_0/U0/PS8_i/EMIOENET1MDIOTN}] -to [get_ports {mdio_enet1_mdio_io_p}] 9.0

you get a clock segmentation warning.

What is the proper way to do this?

Thanks

[anunesgu · Accepted solution]

For other Customers experiencing this issue, 

This issue was fixed in Vivado 2019.2.

As a workaround, please manually create the clock constraint using the following command:

 create_clock -period 400.000 -name mdio_mdc_clock [get_pins design_1_i/zynq_ultra_ps_e_0/U0/PS8_i/EMIOENET0MDIOMDC]

After that, please run implementation again and generate a new check timing report to verify the workaround corrected the issue.

Thank you,