Good Tools for Drawing Schematics
I'm looking for a schematic editor/capture tool to use in the very initial steps of a digital design. This is, as a block diagram editor, instead of inkscape or similar. The idea is to replicate schemas like this without doing it on paper:
The final design, although it would be perfect to have VHDL/verilog export capabilities, will be done by hand in HDL language. I need a tool to design an initial block diagram, with the main signals/buses and elements, as well as the pipeline of the datapath of a hypothetical custom processor.
I've checked Xilinx ISE, gEDA (gschem) and other propierary tools, but none of them is suitable for this as they are quite specific (ISE) or the opposite (gschem). Here ins stack I've found some questions, as this. However, I looking for a closer approach to processor architecture, datapaths, registers, memories, arithmetic units, etc. A professional look & feel is also desirable.
Any idea would be welcome.