Viewing posts for the category Blog Post
I get some comments like this: “All the other FPGA boards have loads of blinking LEDs. And they have bunches of buttons and switches! My XuLA board has nothing!”
Now when you learned how to ride a bike, you might have started out using training wheels. These were helpful – they let you get experience with the bike without getting hurt (unless your parents push you out in a busy street – but that's another story). But after a while, you couldn't wait to get rid of those training wheels. Wherever you went, they just screamed out: “I'm a bike-riding noob! Come give me a wedgie!” But the worst part was they got in the way; you couldn't get any speed up because those training wheels were dragging on the ground. Luckily, they weren't welded to the bike and you could take them off. Then you could use the bike for what it was for: getting you from here to there faster and easier than being on foot.
LEDs and buttons are similar to training wheels: good when getting started, but a hindrance after that. <<more...>>
A few years ago, my sister and I decided to plant a stand of corn in addition to the regular garden on her farm. This entailed tilling a 50' x 15' area, hoeing the dirt up into about twenty mounds, shaping the mounds for holding water, punching four holes in each mound, and, finally, placing a few kernels in each hole. Then we planted beans among the mounds to try and crowd out the weeds. <<more...>>
Some people have commented that the 12 MHz clock on the XuLA FPGA board is too slow for practical use. What they've missed is the Spartan-3A FPGA has on-chip digital frequency synthesizers (DFS) that can multiply the clock to over 300 Mhz. To show how easy it is to do this, I've added another chapter on using the DFS to my new book about doing FPGA design using Xilinx ISE WebPACK and the XuLA board. It just takes a few lines of VHDL and you can have almost any clock frequency you want between 5 MHz and 320 MHz.* <<more...>>
We all have 'em: tools that let us do things easier and faster. Some we buy, others we make. This is my first entry about one of my favorite tools: an Eagle ULP I wrote that lets me do cost estimates on boards I'm designing using real-time prices fetched from Digi-Key. <<more...>>
I'm writing a new book about doing FPGA design using Xilinx ISE WebPACK and the XuLA board. I've reproduced the preface for the book below. Here are the important points: