In reply to kathula venkatesh:
When crossing coverpoints, cross bins for all combinations of coverpoint bins in the cross get created. So you start with 22322*2 = 94 automatically generated cross bins. The bin specification is used to merge or eliminate bins in the cross. The bin specification describes a set of matching value to include in the selection.
The mode1 section matches 3 bins since you did not include c_mem. It is like a don’t care. Those 3 bins get merged into the bin mode1.
binsof(c_mem) intersect {5’b11111} match no bins of c_mem, so the mode2 bin will be empty/eliminated.
mode3 matches all 96 bins, so they all get collpased into a single bin.
binsof(c_mem) intersect {5’b00000} also matches no bins of c_mem, so the negation of that matches all the bins, so again all 96 bins get collapsed into one.