Added clogb2 function

Author: pConst

clogb2.svh

@@ -0,0 +1,24 @@
+//------------------------------------------------------------------------------
+// clogb2.svh
+// published as part of https://github.com/pConst/basic_verilog
+// Konstantin Pavlov, [email protected]
+//------------------------------------------------------------------------------
+
+// INFO ------------------------------------------------------------------------
+//  Calculates counter/address width based on specified vector/RAM depth
+//
+//  Function should be instantiated inside a module
+//  But you are free to call it from anywhere by its hierarchical name
+//
+//  To add clogb2 function to your module:
+//  `include "clogb2.svh"
+//
+
+function integer clogb2;
+  input integer depth;
+
+  for( clogb2=0; depth>0; clogb2=clogb2+1 ) begin
+    depth = depth >> 1;
+  end
+endfunction
+