12-22-2014 06:16 AM
I am using a MMCME2_ADV in a zynq 7020 device, with CLKFBOUT looped back into CLKFBIN through a BUFR, Compensation is set to ZHOLD. I am doing my builds through EDK/XPS. In map, I get the following error:
ERROR:PhysDesignRules:2257 - Unsupported MMCME2_ADV connectivity. The signal
ircamera_deserializer/ircamera_deserializer/calibration/mmcm_fbin on the CLKFBIN pin of MMCME2_ADV comp
ircamera_deserializer/ircamera_deserializer/calibration/clock_generator with COMPENSATION mode ZHOLD must be driven by the CLKFBOUT pin on the same MMCME2_ADV through a BUFG, BUFH or BUFR.
It seems to me like the situation map is complaining about does not occur in reality. What am I doing wrong? How do I remove the error?
12-23-2014 12:54 AM
12-23-2014 04:35 AM
I am using ISE 14.7. Upgrading to Vivado is not an option for me at this time unfortunately.
Is there a way to force the compensation in UCF for ISE? Could you give an example?
12-23-2014 01:53 PM
12-23-2014 09:53 PM
Follow these steps:
1. Open Synthesized in PlanAhead. See snapshot below: (by double clicking on Floorplanning PlanAhead)
2. Once the design is invoked in PlanAhead, select the MMCM and change its properties (compensation property) using properties window: See below snapshot:
Then click on Save button (top-left corner) and close the planAhead.
Next run implementation in ISE.
Thanks and regards,
12-25-2014 08:48 AM
I did open my synthesized design in planahead and checked the MMCM attributes, but the compensation is already set to ZHOLD (see attached image). I also tried adding the following line in my UCF:
INST "ircamera_deserializer/ircamera_deserializer/calibration/clock_generator" COMPENSATION = ZHOLD;
So it seems like the compensation attribute is being correctly set, but somehow the design still fails DRC.
I've added a schematic of the design in the hope of giving you some more ideas :) The clocking scheme is as follows:
LVDS clocks -> IBUFGDS -> ISERDESE2 (D to O) -> MMCM_ADV -> BUFR (clkfbout to clkfbin)
From the CLKOUT0 pin of the MMCM i drive a BUFR and BUFIO for a deserialization application.
01-08-2015 06:27 AM