GTM transceivers using under sampling

[michi.b]

Dear transceiver experts,

I've a question regarding the new GTM transceivers.

In UG581the following limitations are mentioned:

• PAM4 modulation:

  • 58 Gb/s – 39.2 Gb/s

  • 29 Gb/s – 19.6 Gb/s

• NRZ modulation:

  • 29 Gb/s – 19.6 Gb/s

  • 14.5 Gb/s – 9.8 Gb/s
• I'd like to know if it's possible to do under sampling with an own module after the PMA to achieve lower data rates, e.g. 4.9Gb/s = (9.8Gb/s) /2 in NRZ or (19.6Gb/s) /4 in PAM4
• Are there any IP cores or Wizard adaptions planed to achieve lower data rates, too?

Best regards,

  Michael

[karnanl · Accepted solution]

Hello Michael @michi.b 

Xilinx UltraScale+ GTH/GTY can receive 4.9Gbps.
US+ Virtex device such us VU29P also has GTY channels. I do not see any advantage using GTM for this usecase.

There is no plan for GTM to support 4.9Gbps, since this is out-of LCPLL spec.

Regards
Leo