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I'm very new to programmable logic world and have never worked with any HDL languages, but I certainly want to get started with FPGA. At the moment the goal is to develop/simulate simple 8bit CPU and maybe (in the future) do some graphic output.

As I understand there are two big players in the FPGA market: Xilinx and Altera. I have very though budget - 40$. Also, I'm a little bit confused of capabilities that varies from board to board (regardless of vendor). For example, some of the boards - even based on the same chip - has VGA port (or COM/RS-232 port), RJ-45 socket and even audio line out/in; some of them just have an array of pins (if so does it mean that FPGA has Digital/Analog I/O?). So I'm curious if it will be possible to "extend" capabilities (eg add D-sub port to output some graphics or phone socket for audio) on the board that doesn't have a required interface.

I need an advice and certainly some explanation what the board better to buy in my "noob" case. I use aliexpress to buy such a things, so here are some examples I've found "appeal":

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closed as off-topic by Ignacio Vazquez-Abrams, PeterJ, Asmyldof, Daniel Grillo, Chris Stratton May 6 '16 at 13:26

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    \$\begingroup\$ Don't buy a board with an FPGA, which is no longer supported by the vendors tool chains. E.g. Xilinx Vivado supports only 7-Series or newer devices (e.g. no Spartan). Altera Quartus 14+ (current version is 15.1) discontinued support for Cyclon III and Statix III or older. \$\endgroup\$ – Paebbels May 6 '16 at 8:30
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Honestly: it does not matter much.

Both companies are about on par with

  • features: lots of lookup tables, some dedicated blocks like multipliers or I/O),
  • development environment (annoying)
  • pricing (all the good features are available only for serious money)

Deciding on a board without a very concrete project in mind is always difficult, so I'd pick a project and then decide on the board by the available peripherals on the board.

FPGAs only have digital I/O lines and a few dedicated clock inputs and outputs that can be used to synchronize communication with the outside world. If you need analog input, you need a separate ADC, for analog output, you need a DAC, and for USB you need a USB controller (the USB protocol cannot be sensibly emulated with just digital I/O ports).

Having a display is nice, but it will be difficult to set up unless you just use pre-made components -- but on the other hand it is a good learning experience because it has several stacked layers.

Protip: You can also add WS2812 LED strips as a peripheral easily.

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  • \$\begingroup\$ Xilinx 7 series devices have a multichannel ADC \$\endgroup\$ – scary_jeff May 6 '16 at 8:02
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    \$\begingroup\$ If the FPGA itself have a little difference, what about the difference of software they use? Xilinx ISE Webpack vs Altera Quartus Prime? \$\endgroup\$ – Timur Fayzrakhmanov May 6 '16 at 9:18
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    \$\begingroup\$ These only differ in small details as well -- where things are in the menu, and how their editor behaves. Both allow you to edit VHDL and Verilog, configure readymade components, compile, download and simulate. Both editors are annoying (the one in Quartus for example always suggests word completions that don't necessarily fit the context), but since you can run either compiler from the command line, replacing the editor is easy. \$\endgroup\$ – Simon Richter May 6 '16 at 10:02
  • \$\begingroup\$ @SimonRichter, Great answer, and very helpful. I don't get why this was closed. This is kind of a long shot, but I'm trying to learn how an 8 bit MCU is built as well. Could you give any out direction where'd you start? Where I'm at is trying to peel away from where you go down further from just knowing WHAT the assembly instructions do but understanding what is happening at the physical layer. I'm kind of growing out assembly, I want to go deeper... \$\endgroup\$ – Leroy105 Jan 24 '18 at 18:21
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The only difference I'm aware of is that the latest xilinx parts have slightly higher maximum pin toggle rates (~1GHz vs 0.85GHz), I think that's it. FPGA's don't have analog IO, the VGA port is controlled by a set of simple DACs driven by digital data from the FPGA, but it won't do anything without being configured, an FPGA does absolutley nothing without its configuration file

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