Hm, I have just come up with an interesting idea for a logical pulse generator type of thing that would serve as a great introductory project. Might be possible to do with SPLDs, though a bit difficult given the number of input bits needed for full implementation. We have some SPLD stuff in the lab, though so I could play with a sort of smaller version of this before I decide on what to order for a more complex device. Cool
Hm, so would I want one of these boards from Digilent, or something more like what's on easyfpga.com or ftdi-chip's morph-ic? I think I would lean toward the latter two. It's kind of nice that the digilent boards have all these IO devices like the 7-segs, buttons, switches, VGA ports and such. However, I may not be using many (or any) of these things in some applications and I may prefer to have more IO lines for my own purposes. I have a nice handful of these push-buttons and 7-seg displays in my misc. box at home, and I can borrow a row of DIP switches from the lab any time I want so it seems unnecessary and potentially "in the way" to have all of these things hard wired into the board. I also don't know if I like how they just have four six-pin headers for IOs that are obviously intended for their proprietary modules. It's a cool feature if that's what you want to use, but I don't really want to buy those things.. I think I'd rather just have all the IO pins available to me to do as I please with them. The odd thing is that with these Digilent boards it looks like you can get more for the same price or less compared to the other ones.. but on the other hand some of the "more" that you get is just dirt cheap stuff anyway, that's easy enough to pop into a breadboard and wire it up yourself.
for actually programming and coding on an FPGA, i would recommend the software from Xilinx.com, as their dev software is free, and you can get dev boards with FPGA for about £50 from third party sites. My University use the Xilinx software (amongst others) and Diligent Dev boards, and they did a scheme for us to buy a different (compatible) dev board for £50 from another company that i forget the name of. (if you want more info il ask my class mates when i next see them).
Definitely use Xilinx tools. As for the dev boards, I'd be inclined to start off with the board with some peripherals already added - just so you can be sure that any errors are with your code only! Although it's pretty hard to go wrong with VHDL because it'll just throw hundreds of errors if there's a mistake!!
Alright, that sounds reasonable. I'm turned off by the BASYS board as it only seems to have 16 usable IOs and the rest is taken up by a lot the peripherals, which I may not use much or at all. The Spartan-3 board looks to be a little better about that, and has peripherals that actually might come in handy for some of my projects (PS/2 keyboard input!)
Does anyone know anything about these Hirose connectors that are on some of the Digilent boards? A lot of IO pins are going to these things on the boards that have 'em. I gather that it's supposed to be sort of a board-to-board connector, but is there some way to break these out and use individual pins on a breadboard or something similar? Feels like an awful waste to me to have so many pins hooked up to a connector that I might not use...
i do know hirose gives free samples b/c for work i had to order some for a project... i believe they do mostly small stuff, but i coud be wrong... its been a while
Aha, it has been brought to my attention that digilent sells a breadboard that connects to that board-to-board connector. So the Nexys would be acceptable but I'd have to get the JTAG cable separately since it appears the USB programming interfaces won't be usable in Linux. Furthermore, the serial, VGA and PS/2 ports would have to be purchased separately with that board if I ever decided I wanted to use them. With the Spartan 3 starter board, there are headers that I can probably connect to my own breadboard with no issue, and it comes with the parallel JTAG cable which I do believe I'll be ok using in Linux.. would just have to get the USB version of the JTAG cable if I ever needed it (don't need it I guess, both of my machines have parallel ports). Works out probably about the same either way, depending on what other devices come on each board (memory, power supplies, whatever else). Well thanks for your input guys, I'll take my time figure out what to do.. maybe I'll be back with questions or to show off some manly projects some time
Hmmm, so I am trying to decide what book to get for reference on VHDL. The Designer's Guide to VHDL mentioned by SteveyG looks a little expensive, but I can get it if it's really the one to get. Of the books that came up on Amazon, "Circuit Design with VHDL" looks to be more reasonably priced, but I don't know if it's very good.. There's also one called "Digital Design and Modeling with VHDL and Synthesis" which is a little more expensive but may also be more in-depth. Any suggestsions? Thanks again, Steve
I was in Southampton uni yesterday applying for electronic engineering and i asked the prof giving the lab tour if he could recommend a good introductory book, he suggested "digital systems design with VHDL" by Mark Zwolinski ( also a prof at Southampton ) i got a chance to read a bit of it in the library there and it did seem pretty good, started with very simple stuff but ended with fairly complex designs. I think i will get a copy. The other thing the prof said was that VHDL isnt a very... elegent... language and that theyre thinking of switching to verilog, just something to consider. Moriquendi
I can see what he means about VHDL, it's a little long winded, but it basically ensures full functionality. There are a lot of things in VHDL that you cannot do in Verilog and so Verilog is a bit behind the times with a few concepts that are taken for granted in VHDL. My experience with Verilog got me a bit fustrated with just with the basics! Like simple signal stuff which are easily dealt with in VHDL by using standard_ulogic and standard_logic.
Hey, let me know how your application goes, I will be going to Southampton Uni on the MEng Electronics Eng. this october depending on grades. I had a look in the soton uni waterstones, where they sell the degree specific books, and I noticed that in the electronics and physics section, quite a few of the profs write their own reference books!
I got an offer, AAB for the same course, looks like i might see you in october. From what i saw of VHDL it seemed pretty straightforward. Moriquendi
Doing Electronic and Electrical Engineering at Aston. Doing a Programmable Electronic Systems module at the moment using C167's. have been keeping a half eyeball on this thread, looks interesting ish, though i am not sure that FPGA or More complex Microcontroller/microporcessor development is possible in a home environment Jaz_knos
Hahaha, Soton was awesome! I'll see you guys there in october if I don't get my first choice offer. I got AAB for soton too. Should be cool... I want to get into FPGAs too, they look cool. It's just they're a bit pricey, and there's so much you can do with PICs and AVRs anyway. Also, it's only the really high end stuff that they're doing with the coprocessors that drop into Opteron sockets etc. that's truly impressive.
@ Jaz, it is possible to do this kind of development at home you just have to be clever about some things, plus ebay is your friend when it comes to getting equipment. Xilinx give away a free version of theire software and a development board can be had for $60 (havent managed to find one on this side of the atlantic yet). As for microprocessors have a look at the Parallax Propeller, 8 core 32bit 80MHz and costs only 15 quid. Southampton was great, all the professors i met were nuts in one way or another. Moriquendi
