v 0.4 of my CPU is a decent delta. The code is now cleaner, more generic and so more flexible and easy to expand. The internal structure has expanded to include a new flag, zero ("Z"), to go with the existing numerical overflow flag ("OV"). Most importantly, these in turn facilitate conditional branching. Yes Sir, we can loopy! Follow the "Read More" link at the right for an explanation of the new instructions. | 24/02/2013 |
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Baby's first steps. OK, I'm not good at keeping up with the blog. That's because I've been having far too much fun (and far too little sleep) progressing my project. But I think the results are worth it. The image above (click it for a larger version) is a simulator trace for my CPU executing one of its very first test programs :-) Follow the "Read More" link at the right for more details. Clearly I needed some sort of FPGA hardware to play with, as well as some software to program it. So my first decision was which FPGA vendor to go with. I'm not saying it was the best first decision, but I'm nothing if not honest.
It seemed that the two main vendors are Xilinx and Altera. Decisions, decisions... 10 years back I was building small robotic items using PIC microcontrollers. More recently I've played with Arduino and PICAxe (which is amazing yet massively underrated). I'm well aware that Raspberry Pi is currently en vogue, and being staunchly pro-education (Mum was a teacher!) I applaud Eben Upton's motives and success.
But last week I decided that I simply wanted to do something that was, for me at least, a bit different. And FPGAs were a niggling "hole" in my repertoire of experiences. Hence this little project. A bit more about my background after the break. This is me starting to get back into microelectronics, or at least a new-to-me aspect of microelectronics, namely chip design using FPGAs. Why? Because I want to and I can.
I'll admit upfront that I'm not 100% new at this, having earned a B.Sc. M.Eng in Microelectronic Systems Engineering from UMIST. But that was, literally, last century. I always keep a log book for all my projects. This time round I thought I'd have a go at this blogging "lark". Hence this blog, a record of my learning curve in getting to grips with FPGAs, the associated software, and the road to creating my own "chip", quite possibly my own little CPU. My main passion, however, is (for now!) chess, and I might just post a few random thoughts about my chess endeavours on this page. Thanks to my good friend John M for suggesting Weebly. John knows a heck of a lot about a heck of a lot, but he does think that Firefly is amazing. Ah well, even he can't be right all the time ;-) |
AuthorJust another hobbyist starting out with FPGAs. Archives
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