The no_clock check reports the groups of active
leaf clock pins with no clock definition. Each group has a clock source point where you must define
a clock to clear the issue.
% check_timing -override_defaults no_clock
1. checking no_clock
--------------------
There are 15633 register/latch pins with no clock driven by root clock pin: sysClk
(HIGH)
There are 148 register/latch pins with no clock driven by root clock pin:
mgtEngine/ROCKETIO_WRAPPER_TILE_i/gt0_ROCKETIO_WRAPPER_TILE_i/gtxe2_i/TXOUTCLK
(HIGH)
There are 8 register/latch pins with no clock driven by root clock pin:
usbClkDiv2_reg/C (HIGH)With check_timing, the same clock source pin or
port can appear in several groups depending on the topology of the entire clock tree. In such case,
creating a clock on the recommended source pin or port resolves the missing clock definition for all
the associated groups.