A Field-Programmable Gate Array (FPGA) is a logic chip that is configured by the customer after manufacturing—hence "field-programmable".
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964 views
Readable and educational implementations of a CPU in a HDL
Can you recommend a readable and educational implementation of a CPU in VHDL or Verilog? Preferably something well documented.
P.S. I know I can look at opencores, ...
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6answers
1k views
Why is open hardware so rare? [closed]
I'm trying to understand why open hardware is so much harder to come by than software. I've tried looking around online and I couldn't find as satisfactory explanation.
I understand that hardware is ...
22
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14answers
8k views
Most affordable FPGA dev kit for learning VHDL and FPGA theory?
I'm looking for something that I can play around with but not spend too much on. I'm not eligible for an academic discount so take that into account when making suggestions.
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5answers
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What is an FPGA?
I've seen a lot of people talking about FPGA's before and I know that it stands for field-programmable gate array but how does it work and what is the purpose of using an FPGA?
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10answers
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Cheapest FPGAs?
How cheap do FPGAs get? I know they're more expensive than microprocessors of comparable capability, but I wonder if there exist FPGAs that could contain a Microblaze soft core running Linux, while ...
20
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5answers
2k views
Looking for open source FPGA hardware and dev tools
Investigated FPGA boards but cannot find open-sourced board and vendor-neutral FPGA development tools:
The ORSoC manufacturer boasts open-sourcing on its website but I cannot really find strong ...
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9answers
2k views
How to choose an FPGA?
I need to do digital signal processing on 8 analog lines at 10 kHz. This is quite a demanding task, and I was thinking that an FPGA might be the right approach. I am currently looking at dev kits ...
14
votes
7answers
1k views
Can an FPGA design be mostly (or completely) asynchronous?
We had a very short FPGA/Verilog course at university (5 years ago), and we always used clocks everywhere.
I am now starting out with FPGAs again as a hobby, and I can't help but wonder about those ...
14
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2answers
671 views
How is ASIC design different from FPGA HDL synthesis?
I've had some experience with FPGA/HDL tool suites such as Xilinx ISE, Lattice Diamond, etc. The general workflow is writing Verilog/VHDL, simulation, testing and then programming the FPGA.
I've ...
13
votes
8answers
727 views
Microcontroller/cpu for fast trigonometry in robot?
This concerns hardware that does weighs little, because a (fat cat sized, 6 legs with 3 DOF) walking robot should carry it around. Because of that walking it'll need to do a lot of trigonometry (using ...
13
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7answers
2k views
Project to learn VHDL
I am an EE student and can write [at least simple] programs in more languages than I have fingers. I have just started learning VHDL and I was wondering what a good project would be to really get to ...
12
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6answers
679 views
What are the advantages of using FPGAs over TTL in intro computer architecture?
I teach the one and only computer architecture course at a liberal arts college. The course is required for the computer science major and minor. We do not have computer engineering, electrical ...
12
votes
4answers
532 views
Receive several fm-radio stations at the same time (~10-20 MHz wide summary at 90MHz radiofrequency)
What is a cheap way to receive and record on PC several (tens) of fm-radios (public, e.g. news, music, etc)? Such radios uses frequencies like 90.4 MHz or 102.7 MHz, sends a stereo (sometimes with ...
12
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8answers
8k views
FPGA development kit for beginners , Spartan6 or Spartan3?
I intend to purchase an FPGA, development kit and I have looked at both the Xilinx and Digilent website. Both seem to have good development kits.
I have never worked with FPGA's before but have some ...
12
votes
2answers
3k views
Any native Mac OS X environments for getting started with VHDL / FPGAs?
The title pretty much sums up my question: Are there any native Mac OS X environments for getting started with VHDL / FPGAs?
12
votes
2answers
344 views
How do you tell if an FPGA is capable of running an ip core?
I'm looking at a cheap board to start on and I'm wondering if I'll be able to fit a Picoblaze, LEON, S1, or OpenRISC core on there. Is there any way to tell?
12
votes
1answer
210 views
Soft-CPU verification
I'm currently in the process of designing a simple CPU in VHDL using Xilinx ISE and ISIM. The design portion is going remarkably well, but I can't seem to figure out a way to do verification in a ...
11
votes
4answers
8k views
FPGA's vs Microcontrollers
I've worked on the Arduino family (specifically the Sanguino), built a few simple devices and a simple phototrope. I am thus pretty comfortable with microcontrollers - specifically Atmel's. I'm ...
11
votes
6answers
1k views
How to get a processor design onto FPGA
I recently went on a long voyage of self-teaching logic design. The final product of this is a functional 16 bit CPU that works exactly as designed in a simulator. Now I've just started looking into ...
11
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5answers
697 views
Is an FPGA viable for such a project?
I am currently working on Super OSD - an on screen display project. http://code.google.com/p/super-osd has all the details.
At the moment I'm using a dsPIC MCU to do the job. This is a very powerful ...
10
votes
5answers
1k views
Embedded linux on FPGA
I have very limited experience with FPGAs (Altera - used only the visual design tools).
I am planning for a new project in which I need FPGA and I could benefit a lot from an actual linux running ...
10
votes
7answers
1k views
What microcontrollers with programmable logic built in (FPGA/CPLD like) are available on the market?
Inspired by question I would like to ask what microcontrollers with CPLD or FPGA-like functions build in are available? The most interesting would be low-cost ones in friendly packages (non-BGA). The ...
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3answers
1k views
FPGA, first steps
Well this is a continuation of my question on FPGA over here.
I finally selected a Digilent Atlys with a Spartan 6 FPGA, I don't have any prior experience of FPGA's although I have done some amount ...
10
votes
5answers
615 views
What is the XMOS series?
Ok, so I recently have been seeing the name XMOS appear in places. I've looked on their website and searched online but I can't quite figure out what it is? So what is it? It appears to be a cross ...
10
votes
2answers
2k views
When is using latches better than flip-flops in an FPGA that supports both?
The Question:
When is using latches better than flip-flops in an FPGA that supports both?
Background:
It is a well-known principle that level-sensitive transparent latches should be avoided in ...
9
votes
5answers
10k views
Code example for FIR/IIR filters in VHDL?
I'm trying to get started with DSP in my Spartan-3 board. I made a AC97 board with a chip from an old motherboard, and so far I got it to do ADC, multiply the samples for a number <1 (decrease ...
9
votes
3answers
929 views
Is the Microblaze soft cpu better than the Cortex M3 soft cpu
Is the Microblaze soft cpu better than the Cortex M3 soft cpu in terms of functionality?
Given all the buzz about the ARM based processors, I was wondering if to implement an ARM processor on my FPGA ...
9
votes
2answers
608 views
What happens when an FPGA is powered on and left unconfigured?
I am trying to get a general understanding on what happens if you leave an FPGA unprogrammed for a long duration of time.
Suppose you have an FPGA and you leave it unprogrammed for a long period of ...
9
votes
2answers
316 views
Can FPGAs dynamically modify their logic?
It would be theoretically possible for an FPGA to write a configuration image to an external memory, and load the configuration image from the memory to reconfigure itself. This would be "non-dynamic" ...
9
votes
2answers
708 views
Programming multiple FPGAs using JTAG
I have a JTAG chain connecting 4 Spartan 6 FPGAs that I program using ISE iMPACT. The software can program any strict subset of the 4 FPGAs in a row successfully, and in any order. However, when I ...
9
votes
8answers
1k views
Newbie projects on an FPGA?
I'm two weeks away from completing my first college digital logic design course, and apparently there isn't going to be a final project--just a tedious final exam.
So as any curious student would ...
8
votes
5answers
760 views
book recommendations on FPGA
what book titles would you recommend to get started with FPGAs and VHDL?
edit
I noticed that a few of the recommended books date back from 1996. I can imagine that the devices referred to will be ...
8
votes
1answer
779 views
FPGA programming, where to begin
I'm a software developer (C, C++, objective-c, java ...) and I am interested in learning to program FPGAs. Now the question may appear simple to you but please do take time to help me on this one as ...
8
votes
6answers
2k views
Cheap FPGA dev board
I want to begin with FPGA, but I've never worked with once before.
I want a cheap kit, but I don't know where to start. I can find cheap boards, but then I can't get no information about the ...
8
votes
2answers
671 views
What is a false path timing constraint?
In FPGA world, what exactly are false path constraints for an HDL compiler? Why are they useful?
8
votes
3answers
264 views
Compare implementing a simple automation design on a MCU vs an FPGA/CPLD
I have been working with MCU's since the 90's, and I've recently ventured into the FPGA scene with the Spartan6 series chips from Xilinx. Assuming a simple factory automation design with sensors and ...
8
votes
2answers
262 views
How do commercial microprocessors meet timing with a gigahertz clock?
I am having troubles making a relatively simple FPGA design (for an Altera Cyclone IV) meet timing for logic driven by a 250 MHz clock. This makes me wonder how commercial microprocessors (such as the ...
8
votes
4answers
735 views
When is it neater to use VECTOR representations vs INTEGERs?
In the comment thread on an answer to this question: Wrong outputs in VHDL entity it was stated:
"With integers you don't have control or access to the internal logic representation in the FPGA, ...
8
votes
4answers
318 views
Connecting an 80's style computer cassette to an FPGA
I'm re-implementing a 1980's Microbee computer on an FPGA (see here: http://www.toptensoftware.com/fpgabee) and trying to figure out how to do the cassette port. Here's the schematics for the original ...
8
votes
4answers
999 views
Suggested FPGA board
This is my first look into FPGA, but heavy background in software development. Would like to purchase a board to learn with, but would eventually like to be able to run an early 80's style Z80 based ...
8
votes
4answers
570 views
FPGA firmware design: How big is too big?
I have a particularly large signal processing transform that needs to be ported from matlab to VHDL. It definitely requires some kind of resource sharing. A bit of calculation gave me the following:
...
8
votes
1answer
345 views
MD5 VHDL pipeline
I am trying to implement a 3-stage MD5 pipeline according to this link. In particular the algoritms on page 31. There is also another document which describes data forwarding. This is done in an FPGA ...
8
votes
1answer
1k views
How to create an FPGA based Ambilight clone?
Some quick background:
Ambilight is a system on some Philips TVs that analyzes the color information on the screen and then sets some LEDs on the back of the display to project the screen's color onto ...
8
votes
2answers
980 views
When do I need to use a clock buffer IC?
I am designing a circuit and PCB for driving 7 DACs from an FPGA. (DAC is AD9762)
Would it be possible to drive the clock inputs on all 7 DACs with a single clock output (from a PLL output pin) of ...
8
votes
1answer
524 views
Simulating a simple test bench with a synthesized ROM core
I'm completely new to the world of FPGA's and thought I'd start with a very simple project: a 4-bit 7-segment decoder. The first version I wrote purely in VHDL (it's basically a single combinatorial ...
7
votes
4answers
2k views
Are there any Analog FPGAs?
As I understand it FPGAs are flexible "digital" circuits, that let you design and build and rebuild a digital circuit.
It might sound naive or silly but I was wondering if there are FPGAs or other ...
7
votes
2answers
527 views
Soft core Processors VS Hard core Processors
I am doing a study on FPGA interfacing with Microprocessor such as ARM9.
Came across the concept of Soft core and Hard core Processors in my study. May I know what is the comparison between these 2 ...
7
votes
4answers
1k views
Reset: synchronous vs asynchronous
I've been working with fpgas for years, and always used synchronous resets for every parts (that need it) of my circuits. It helps the circuit to be globally reset at a given clock cycle.
However, I ...
7
votes
3answers
816 views
Export restrictions on components like FPGAs
I'm considering upgrading the FPGAs on a product of mine from small Spartan3A-200s to low-to-mid-scale Spartan6s. The Spartan6s are actually cheaper, and I've just about outgrown the 200. It looks ...
7
votes
1answer
633 views
All Digital Phase Lock Loop
I'm looking to implement a phase lock in an FPGA without using any external components (other than the ADC). For simplicity locking to a simple binary pulse is adequate. The frequency of the signals ...
