The circuit board arrived from Elecrow PCB in China, and it works without modification! My friend Brian from Canada helped me out again, laying out this PCB in short order. He did a great job!
Soldering the half-mm pitch and MEC6-140 connector turned out to be quite a challenge. This is mostly because I’m out of practice. I have since also added the necessary filtering caps to ensure a clean signal.
Here’s an image of the board attached to the FPGA eval board. It’s tiny. 1.9 x 1.6 inches!
I think it looks sharp, but more importantly, the SRAM has 10ns access time consistently, and the interface is easy peasy! No more messing around with SDRAM. We still have the 8MB SDRAM available, albeit with a longer latency.
This circuit board will be our frame buffer. The CPU will (mostly) write to it, and the video driver will read from it. The 4MB size is plenty of room for high resolution and color depth. Even better there’s room for another 4MB if need be!