We were discussing the future of the first-year digital electronics module here recently. We’ve just built some digital logic boards that allow students to program a CPLD on the board to produce a variety of dice, traffic light controllers, slot-machine systems, and all the usual sort of introductory digital systems designs. Currently we use the Xilinx ISE tools, which is great in that their WebPACK systems allow the students to install the software on their own machines free of charge. The problem is that the Xilinx schematic entry tools (which we have to use as the students haven’t learned VHDL or Verilog by the time they take this course) are not particularly robust, and students spend a lot of time, and need a lot of help, getting the software to work.
Since almost no-one in industry uses schematic entry any more, I can see it’s not a high priority for Xilinx to spend much time on this, and the schematic design route might even disappear in a future version of ISE (after all, the facility to draw test waveforms has already gone, so the students have to use VHDL test benches with their schematic designs already). If Xilinx do remove schematic entry from a future version of the ISE, then we’re in trouble…
…unless we can find an alternative design route from schematic to CPLD. This is where it gets interesting. These are first-years, they don’t do anything particularly complex (they learn VHDL before they’re required to do any complex design) so we wouldn’t need anything much. Now I already have a digital simulation program with schematic entry facilities. I reckon I all need to add is hierarchy, busses, and the ability to output the schematic design to VHDL. None of which sounds that difficult, and all of which sounds like it could be quite fun.
Writing our own schematic -> VHDL tool would also allow us to write very simple, easy to understand and well-commented VHDL. (Some of the automatically produced VHDL I’ve seen from other tools is unreadable, at least by humans.)
I’m actually itching to get started on this. Maybe I’ll start it up in a slow way, so that if it never happens I’ll not be too disappointed. In the meantime I should be getting on with the stuff that I know is definitely going to get used.
But it’s nice to have a dream…