What is the purpose of driver cell in CTS?

what is the need of driver cell in CTS

Get clocks and high fanout nets excluded from being "attachIOBufed"
They will get IO buffers during feCts using Add driver cell
please explain the above 2 lines in detail

thanks

adddrivercell

A driver Cell in CTS is a point at which a brch of a clock is propagated.. or say a new start point of a clock...so the brances emerging from that point will all be time syncronized wrt the output of this driver cell.


Regarding
" Get clocks and high fanout nets excluded from being "attachIOBufed"
They will get IO buffers during feCts using Add driver cell "

This means.. All the clk nets and high fanout nets had been excluded so that they will be treated more in detail in CTS so as to avoid initial timing violations.. I explained you earlier how high fanout nets cause timing violations an dhow they can be resolved..

This must be a information statement .. not an error or warning as far as I know.. If it is so.. pls inform me in which tool and at what stage, you got this error/warning..