init units and bins, test

calc_tb.sv

@@ -20,6 +20,7 @@ covergroup cg @(posedge clk);
     bins S_MUL = {3};
     bins S_DIV = {4};
   }
+  c11: coverpoint STATE_C { option.auto_bin_max = 5; }
   // c2: coverpoint calc_dut.STATE_C {
   //   bins S_IDLE = {0};
   //   bins S_ADD = {1};