diff --git a/CPP/register_modeling/example_project/utils/BitField.hpp b/CPP/register_modeling/example_project/utils/BitField.hpp
index 9dc87d8..aef84a6 100644
--- a/CPP/register_modeling/example_project/utils/BitField.hpp
+++ b/CPP/register_modeling/example_project/utils/BitField.hpp
@@ -47,10 +47,21 @@ struct BitField
      */
     BitField& operator =(T v)
     {
+
+        // this step can be optimised for systems that support bitbandalias 
+        T mask = ((1ULL << SIZE)-1) << START;
+        _raw &= ~mask;
+        _raw |= ((v & ((1ULL << SIZE)-1)) << START);
+        return *this;
+
+
+
+        #ifdef old
         //TODO: test = problem with |= instead of =
         // mask creation for v : https://stackoverflow.com/questions/1392059/algorithm-to-generate-bit-mask
         _raw |= ((v & ((1ULL << SIZE)-1)) << START) ;
         return *this;
+        #endif
     }
     
     /**