I have two questions below for set_clock_gating_check command which is also highlighted in yellow below:
1. Why for OR and NOR gates, the setup check is performed with respect to the falling edge of the clock input ?
2. Why for OR gates, the non-controlling value is low ?
answering the second question:
if you OR something with zero, you always get something. this is why we say the non-controlling value of an OR gate is zero.