Hi there. What sort of resources would be required to do an introductory project with some FPGA? Would it be wasteful to try to obtain such resources for a likely one-off project? My school doesn't have an engineering department, but we do have an electrical engineer on staff, so I might be able to see if he has anything...
what sort of project are you working on? Are you familiar with VHDL at all? or any other kind of languages used for programming? For simple things you can get away with a microcontroller, you can get started with simple serial port JDM programmer that costs < $10 if you make it yourself. For simple logic functions, a microcontroller would be very slow compared to implementing it with logic chips, or on a FPGA. From what I see though(searching around just now online), FPGAs are pretty expensive too. With cheap ones being in the $9 range. and are in nasty packages like 100TQFP and various BGA packages Browsing though my mouser catalog I see "ANACHIP CMOS spld" devices, which come in 20-40 pin packages. And also, Atmel makes some EEPLDs and CPLDs in 20-28 pin packages at a reasonable price. Ive never programed a CPLD or FPGA or done anything with them, but if you have something you can implement in logic or with a state machine, and want it done fast, why not give it a shot. Overall, what sort of project to you want to do? and does it really warrant a programmable logic device?
I have worked with FPGAs, and while they do have advantages like speed, uControllers beat the hell out of them for flexibility, and package size (finding inexpensive FPGAs in dip format? good luck) learning microcontrollers would be a better investment of your time. I also second the q: what are you doing?
Thanks for the responses so far, guys. Well I am somewhat familiar with microcontrollers, and have used them for a few things, often involving RS232 communications, or RS485 in a current project I'm working on. Basically I want to spend the next year and a half until I graduate learning to work with things that will be professionally useful. I'm an applied physics major but I've decided I'd like to work in hardware when I get out, and looking around at some internships and positions that have hardware tasks, it looks like a lot of these people use FPGAs for advanced technical tasks. As for programming, I'm learning how to use C a bit on the PC end for serial communications and data collection, and I've learned to do some simple but very useful things in assembly (MPASM) with PIC microcontrollers. I don't have any specific project that I *need* and FPGA for, I was more thinking that I come up with something to do so that I can learn how to use 'em as it may be a marketable skill. I do have one of these $11 controllerless 640x480 LCDs from allelectronics, this strikes me as a good FPGA projects since the PIC MCUs are going to be a bit slow for that sort of thing.
Ah yes and I have used a DIP packaged programmable logic device once before, about a year ago in my digital class I figured out how to use one of these ATMEL things to make a latching 7-seg decoder, as all the decoder ICs I could find with latching built in were not the right format (I forget whether it was common cathode or anode that I wanted, but everything I could find on digi-key or mouser was otherwise...). That was interesting, even though I got the logic to work as I wanted, it turned out they couldn't sink enough voltage/current to drive the LEDs I wanted to use, so I said screw it and went with TIL311s in the end, haha! EDIT-- after fishing around, I see that FTDI chip (a company I'm familiar with for their USB-serial devices) has a hand in this thing called morph-ic, an FPGA on a circuit board with headers that can be plugged into a proto board. Looks like a good educational tool, and it's comparable in price to a course book or whatever so if I can get an independent study approved on this I might not mind spending the $ on something of this nature.
u-controllers aren't necessarily more flexible, they just have an easier learning curve. you can almost re-create any IC using a fpga, including u-controllers. vhdl is pretty hard to learn, at least i think so. i agree with conkbot and hawk... use a u-controller if you really want to use an fpga, i would suggest getting a book or 2 on vhdl. you would also need something to flash the fpga with (hardware) and some sort of software. we used ActiveHDL in my class. good luck. edit: you beat me to my post. for a quick introductory you might try to recreate an old ic. our first lab we recreated this chip in vhdl: http://www.ent.ohiou.edu/~webcad/ee490/DM74161.pdf just a thought
Altera and Xilinx make some intro CPLDs. Specifically: Xilinx XC95xx devices Altera MAX7000 EPM7xxx devices These have about 128-256 macrocells and are flash programmable. Both Xilinx and Altera allow trial for the software. I know that the Quartus software for Altera has graphic programming ability (schematic style with libraries). A good intro before investing is here . The chips are inexpensive compared to FPGA, and the programmers can either be built on breadboard or get a cheap PLCC expansion board (AWC from above link or Ebay). These are by no means as expansive as a full blown FPGA, but if you want to work with FPGA, you are limited to developers kits (usually Ebay for $100+) in order to play with them. Plus the software can be hard to obtain temporary licence depending on the company. FPGAs are now more advanced than microcontrollers, now that the newest ones actually have 8/16 bit microcontrollers built into them. But they are also much more expensive. CPLDs are very good at supporting uC's for system design. Its nice to have a CPLD turn 8 inputs into 128 latched outputs. You should be able to use a CPLD to handle that LCD. It will require a very good memory interface design though.
www.fpga4fun.com is another good resource, as well as it's sister site (which is a store) www.knjn.com .
These guys are the guys who make the offical Xilinx evaluation boards: http://www.digilentinc.com/ And their most basic board is: http://www.digilentinc.com/Products/Detail.cfm?Prod=BASYS&Nav1=Products&Nav2=Programmable Which is very nice, as it even has a VGA socket on it. Have a look round the site i suggest. Obviously you can program FPGAs in VDHL or Verilog, but you can also go for the schematic approach, which is rather... romantic. (For lack of a better word)
Ive also been looking to learn how to use FPGAs and/or CPLDs (I already know my way around microcontrollers albeit only in assembly). Can anyone recommend a good beginners book on VDHL or verilog? Moriquendi
VHDL is a really nice language. I used "The Designers Guide to VHDL" as a reference book. It seems to be pretty well written and informative, although I didn't use it terribly often.
"Only" in assembly? In my opinion, that's the way to go anyway You can do it in basic or C, but I personally wouldn't want to. I think low-level programming is perfectly suited to these things. I guess C isn't that much higher level, though, and there are some handy things you can do in it that are tougher to implement in ASM... Anyway, thanks for even more great replies! Between the resources you guys have here and the other stuff I found on my own, I should be able to come up with something...
Yeah, i prefer assembler because its more straightforward and easier to think of things in terms of registers which makes things easier for me. Ive never learned a high level language on the PC and im only just getting round to learning object-based programming. @ SteveyG, do you think that book is suitable as a first introduction? Moriquendi
I'd have to have a look through the book again at the weekend, but from what I can remember, it explains everything you need to know right from the beginning.
Thanks, I would appreciate that but it sounds like just what im looking for. Is there any advantage to learning verilog over VHDL or the other way round? Moriquendi
People are religious to one or the other, but the general trend is that Europe use VHDL and the US use Verilog. So if you learn VHDL, it's more likely to be of use to you in a job.
Thanks SteveyG thats been a great help to me. Can i ask you, do you work with this kind of thing or is it a hobby? Moriquendi
