Will put together this amazing project that will knock your socks off! Its a Z80 implementation for the Papilio Pro that runs CP/M, MP/M, and UZI operating systems. It’s based on the T80 core from OpenCores and has some great additions such as using Hamster’s SDRAM controller for heaps of memory. This may be the fastest Z80 we’ve ever heard of, running at 128Mhz! We can finish Zork in record time with all of that speed! 🙂
Hamster puts together an interesting to read wiki page that puts his new Rigol 1102D to the test. He uses his trusty Papilio Pro to generate the test signals and includes full VHDL source and some great screen grabs from the Rigol 1102D.
The Rigol 1102D looks to be perfect for looking a logic signals clocked at up to 66Mhz (15.2ns) but is out of its depth at 100MHz – I guess this is pretty much due to its 5ns sampling resolution.
As clock signals have twice as many transitions as the other signals I suspect that if you also want to display the clock signal you will be limited speeds of around 33MHz or so. Also, you have to be careful with drive strengths to maintain signal integrity…
Check out this cool project that Corey Kosak published in the forum:
Here’s a project that draws animated shapes on a VGA screen without using any memory! It even includes collision detection.
I thought I’d share my third project with you all. I got sort of obsessed with the idea of driving the VGA protocol without any frame buffer memory backing the display and I wanted to see how far I could get with such a design. I ended up with a cute little program that bounces a few geometric shapes around the screen and also does boundary and collision detection.
Papilio user Matthew Hagerty put together a very nice implementation of a simple SDRAM controller for the Papilio Pro FPGA. Written in VHDL, it sacrifices some speed for ease of use and simplicity. After all, not every project needs to use the full capacity of the SDRAM chip.
You can read about his epic adventure learning the ins and outs of SDRAM, simulating his code, and finally running on hardware in this forum thread.
Jim’s next goal is to attach Peripherals to an IO bus such as the OPB bus, or even better, the open source Wishbone bus. This forum thread seems to say that it should be very easy to connect Wishbone peripherals to an OPB master. If that is the case, it would be very cool to add the MicroBlaze MCS soft processor to the Papilio Schematic Library and set it up so all the Wishbone peripherals could be connected to it!
Not a fan of the Arduino IDE and its lack of a debugger he was intrigued by the Vivado SDK with its C editor and debugger for the Microblaze MCS. He quickly jumped in and was able to get a full solution running on free Xilinx software. He put together this excellent tutorial to show the rest of us how it can be done! Thank you Jim, this is great news.