1. Home
  2. Field-Programmable Gate Arrays
  3. MGT Clocking

MGT Clocking

I am currently trying to free-up some DCMs for use in other parts of our design, so I am trying to make some MGTs share DCM outputs. Currently I have one DCM per each of the eight MGTs which uses all of our DCMs. For reference, we are on a Virtex II-pro trying to communicate at a rate of 2.5Gbs in two-byte mode. Xilinx document UG024 talks about a case where no DCMs are needed at all, but it isn't clear on when this solution is suitable (pg.

46). I thoguht we may at least be able to use one DCM for the top four MGTs and another for the bottom four. Any thoughts or experiences related to this issue or clocking MGTs on a Virtex II in general would be appreciated.

---Matthew Hicks

Reply to
Matthew Hicks
Loading thread data ...

If the 8 MGTs are all running from the same reference clock source then you only need one DCM+BUFGs circuit to drive all of the TX and RX user clocks in the device. The only use for individual DCMs is if they are running on different clocks.

Ed McGettigan

-- Xilinx Inc.

Reply to
Ed McGettigan

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.