Pls. explain clock phase & skew phase

[useless_skew]

In the magma commands, I came across two switches -clock_phase and -skew_phase. Can anobody explain me abt these two?

Thanks.

 

[vlsitechnology]

Lets say there is a clock of 10ns and the skew is
1ns.. so the timig path will be checked for 11ns. In
which 0-10ns will be Clock Phase and the 10-11ns will
be Skew Phase.

 

[vinayshivakumar]

clock phase - when you define a clock two clock phases are created (one for rising edge and one for falling edge) - clk:R and clk:F.

"A clock phase is the basic element of a clock. Each clock domain created with the
force timing clock command creates two clock phases: one for the rising edge
and one for the falling edge"

skew phase - You put multiple clock phase (eg clk1:R and clk2:F ) in one skew phase.
This is useful for skew balancing different clock phases . All the clock phases in a skew phase will be balanced during CTS.

Hope this clears your doubt