On Apr 30, 2011, at 5:19 AM, Herbert Graf wrote: > Wires CANNOT be "written" to by an always block. They can only be =20 > driven > by the instantiation of another block, or assigned to by an assign > statement. > > In your case, you're driving ssreg in an always block. As such, you =20 > have > to declare ssreg as a "reg". Interesting. This decoder is entirely combinatorial; how would it be =20 written to use plain wires as outputs ? (without knowing anything at =20 all about verilog, and only a little about PLDs, that's sort of what I =20 would have expected "always" block to do...) BillW --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .