Add description of osvvm_fsm_psl_coverage example

README.md

@@ -8,6 +8,13 @@ Example to use OSVVMs CoveragePkg package to do FSM state coverage. State change
 in an object of type CovPType. The testbench accesses these state coverage data CoveragePkg procedures. So, the testbench
 can react to the FSM coverage if necessary. Furthermore the state changes are checked by some PSL assertions.
 
+### osvvm_fsm_psl_coverage
+This is the same as the osvvm_fsm_coverage but instead of using cross coverage of previous and current FSM state it's using
+PSL endpoints to cover FSM state changes. There is a PSL endpoint for each state change we want to cover. The endpoints
+are synched in clock domain and used as simple BINs to do FSM state coverage as in the osvvm_fsm_coverage example.
+This example shows the power of evaluating PSL endpoints in VHDL, as you can describe complex behaviour over time a lot
+simpler in PSL than in VHDL.
+
 ### psl_endpoint_eval_in_vhdl
 Example to show a recently feature added to GHDL which allows to evaluate PSL endpoints in VHDL code. It simply defines
 an PSL endpoint and sets a boolean value dependent on the value of the PSL endpoint.