12-19-2019 07:11 AM
Hi,
where to see how many MMCM is in a clock region of xcku5p. I am using MMCM from a clock region X0Y0 of xcku5p which is automatically taken by vivado after assigning the rference clock pins (see attachment).
I have critical timing issue which is not even solved by using different strategies for synth, opt, place and route design. Therefore would like to move mmcm close to obuf to see if it helps.
If there are more than one mmcm in a clock region, how to use other mmcm in the same clock region? which constraints need to be given?
12-19-2019 08:48 AM
There is only one MMCM per clock region. If that one is already used then you need to use one from another clock region. However, if you have two clocks entering on clock capable pins in the same I/O bank (clock region), then one of the two will not be able to use the dedicated connections from the clock capable pins in a bank to the MMCM in the same clock region, and will need to use the CLOCK_DEDICATED_ROUTE=BACKBONE property to specify how the clock will reach that other MMCM; the clock that uses the BACKBONE routing will not be perfectly phase compensated, and hence will he a larger clock insertion delay with more variation.
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