Suppose in the library I found an an AND2 gate whose inputs has fanout_load of 0.74 and 0.82.
What does this fanout_load mean? What is this fanout_load?
fanout_load is an attribute to define the fanout value for a particular port. We can define more attributes for a particular port or pin but the total value must not exceed the max_fanout value.
I know the usage of this fanout_load attribute in synthesis :
sum of fanout_load on a port must be less than max_fanout design rule constraint.
For example : set_max_fanout 2 [get_ports A] is the constraint applied in a design, if INVx2 cell has 0.2 as fanout_load, it means the port A can drive maximum of 2/0.2 = 10 INVx2 cells to meet the DesignRule constraint.