Back from a nice long weekend, although I don't want to take the time to talk about that too much right now. I just want to post a sort notice that I'm receiving preliminary output results from my processor. The "out" instruction (which outputs two 16-bit values, "addr" and "data", to the output ports) is working perfectly. This is the first test of something that "works", and I'm happy about it.
I still haven't completely worked out the mechanics of the writeback path. This means that all instructions which require me to store a value to a register (arithmetic instructions, "mov" instructions, etc) aren't working. At least, I don't think they are working because I don't want to waste time yet to try them. Starting tomorrow, I'm going to try to get this vital pathway working so that I can get some real instructions and programs operational.
Because I've been making many changes to things, my assembler isn't working right now. I've had to change around the word formats and bit orders and everything, so my old assembler code doesn't work. At the moment, I'm converting opcodes to binary by hand. For short 1-instruction test "programs" this isn't a problem. However, once I get things working and start using more complex programs, I am going to want to get that fully operational.
Anyway, just a short update before I head off to bed. I'll probably post more tomorrow, after I've bashed my head against it for a while.