Checks done Before CTS

The checks to be done after placement
1)report_constraint -hotspot
This command shows the top 5 highlighted area which are congested with representing the vertical and horizontal congestion.(local congestion)
eg :
V(31/28)  indicates three more vertical tracks are required in that area .
2)report_constraint -overflow
This command indicates the total tracks vertical and  horizontal overflow
e.g
-1    0   0.00%   2 0.00%
which indicates two tracks are less than the required
3)WNS,TNS
4)SLACK :If the slack is below - 200 ps ,The design can be routable ,make sure that the design is having less -ve slack.

5)Density : try to maintain at 75%(after placement)
6)max_transition : This can be reduced by adding clk_buffers  .
max_capacitance : This can be balanced by using up-sizing of cells
max_fanout :by doing clonning we can divide the fanout ,and can reduce the load.
7)checkPlace : this will do placement legalization of cells.
(this will avoid overlap cells and fix the cells)

CTS:(requirement)
get  the clkbuffers and clkinverters
latency
max_transistion
max_capacitance
max_fanout
skew
ndr
clock exceptions

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