Minor updates to README file

(cherry picked from commit 1ef9d692c8)

README.md

@@ -3,15 +3,17 @@ The original repository is located on my own git-server at [https://git.goodclea
 It is mirrored to github with every push, so both should be in sync.
 
 
-# formal_verification
+# formal_hw_verification
 
 Tests and examples of using formal verification to check correctness of digital hardware designs. All tests are done with SymbiYosys, a front-end for formal verification flows based on [Yosys](https://github.com/YosysHQ). Some examples use the VHDL/SystemVerilog frontend plugin by Verific which isn't free SW and not included in the free Yosys version. See on the [Symbiotic EDA website](https://www.symbioticeda.com) for more information.
 
+There is a branch named [ghdl-synth](https://github.com/tmeissner/formal_hw_verification/tree/ghdl-synth) which uses [ghdlsynth-beta](https://github.com/tgingold/ghdlsynth-beta) as VHDL frontend plugin for SymbiYosys. Furthermore using GHDL(synth) as synthesis frontend allows using PSL as verification language. Only the vai_reg design can be verified in this branch at the moment.
+
 ### alu
-A simple ALU design in VHDL, together with a formal testbench written in SystemVerilog. The testbench contains various simple SVA properties used by assert & cover directives which are proved with the SymbiYosys tool.
+A simple ALU design in VHDL. The formal checks contain various simple properties used by assert & cover directives which are proved with the SymbiYosys tool.
 
 ### counter
-A simple counter design in VHDL, together with a formal testbench written in SystemVerilog. The testbench contains various simple SVA properties used by assert & cover directives which are proved with the SymbiYosys tool.
+A simple counter design in VHDL. The testbench contains various simple properties used by assert & cover directives which are proved with the SymbiYosys tool.
 
 ### dlatch
 A simple test design which generates the `Unsupported cell type $dlatchsr` error using with Verific plugin.