实施错误，[放置30-487]无法遵守实例到设备中的包装

嗨，我在实施过程中面临以下实施错误。
当我将sdc中的时钟周期设置为18ns时，可以成功完成实现，而不会出现任何时序/网络错误。
但如果时钟周期限制在15ns，vivado将在下面生成错误消息。
我附上整个日志文件和屏幕截图供参考。
任何人都可以帮助我找出这个错误的根本原因以及它与时钟约束变化的关系吗？
提前致谢。
错误：[放置30-487]无法遵守实例到设备中的包装。
请分析您的设计，以确定是否可以减少LUT，FF和/或控制集的数量。实例数：触发器：在考虑的设计区域中为217018，在设备中可用2443200（注意：每个切片只能
容纳1个独特的控制集，因此无法打包FF以完全填充每个切片）Luts：426661（组合）426661（总计）在设计区域内，1221600可用于deviceControl集：71574 in device未放置的实例需要79296个切片但只有72012个
设备中有305400个切片可用，因为其他切片可能被放置的实例占用或被排除放置阻止。
runme.log 128 KB



以下为原文

Hi,

I am facing following implementation error during implementation. When I set the clock period in sdc to be 18ns, the implementation can be completed successfully without any timing/nets error. But if the clock period is constrained to 15ns, vivado will generate the error message below. I am attaching the whole log file and a screen shot for reference. Can anyone help me to figure the underlying root cause of this error and how it is related to the clock constraint change? Thanks in advance.

ERROR: [Place 30-487] The packing of instances into the device could not be obeyed. Please analyze your design to determine if the number of LUTs, FFs, and/or control sets can be reduced.
Number of instances:
Flip flops: 217018 in the design area under consideration, 2443200 available in the device (NOTE: each slice can only accommodate 1 unique control set so FFs cannot be packed to fully fill every slice)
Luts: 426661(combined) 426661 (total) in design area under consideration, 1221600 available in device
Control sets: 71574 in device
The unplaced instances require 79296 slices but only 72012 out of 305400 slices in the device are available, because others may be occupied by placed instances or blocked by exclude placement.
            runme.log ‏128 KB