tech – Stupid Tech Misadventures

On FPGA memory block optimization

So this is something that bit me in the ass pretty hard recently until someone far more experienced than me on Twitter was able to help me through optimizing my crappy code, and so I figured I’d make a blog post about it. In Verilog, there’s a concept of a memory. A memory is basicallyContinue reading “On FPGA memory block optimization”

Day 6: The VCP, VRAM, & Clock Domain Issues

So over the last couple of days I started work on the video co-processor (from here on I think I’ll refer to as the VCP) of the Athena. The goal of this co-processor is to get two independently scrolling tilemap layers, 128 sprites, and 256 onscreen colors. This turned out to be a bit ofContinue reading “Day 6: The VCP, VRAM, & Clock Domain Issues”

Day 5: HDMI and VGA

So today I decided to start working on getting some video out of my board. My DE-10 Nano comes with an HDMI port and a video encoder chip built right into it, so that makes a pretty obvious choice of video output. My first order of business was just to see if I could getContinue reading “Day 5: HDMI and VGA”

Day 4: The memory bus and a running CPU program

So last time I got a Motorola 68K up and running, cycling through its entire address space and attempting to execute a dummy instruction. However, in order to get the CPU running an actual program, I need to hook up an actual bus to it. I ended up having to do a hell of aContinue reading “Day 4: The memory bus and a running CPU program”

Day 3: Free-running a Motorola 68K

So today I set about getting a Motorola 68K up and running on my FPGA board. My goal was relatively simple: just get an M68K working, fed dummy 0 values on its data pins and tying the top two bits of its output address pins to a pair of LEDs. As the M68K runs, itContinue reading “Day 3: Free-running a Motorola 68K”

Day 2: FPGA time!

So today my FPGA board arrived! I’m excited because this means I finally get to start experimenting with actually designing all of the Athena’s modules for real now and seeing them in action. Of course, the very first thing I wanted to do was just figure out how to program the thing and make someContinue reading “Day 2: FPGA time!”

Day 1: SNES Gamepad Protocol Tinkering

Continuing my series of talking about my adventures in building an FPGA game console, today I’ll talk about how I familiarized myself with the SNES gamepad serial protocol and got a working physical hardware prototype of being able to query the button states. Now, unfortunately, my FPGA board still hasn’t arrived (it’s scheduled to arriveContinue reading “Day 1: SNES Gamepad Protocol Tinkering”