Anyone here actually do meaningful stuff with FPGA devices?

Thread Starter

ApacheKid

Joined Jan 12, 2015
139
I bought a couple of books on this subject about 18 months ago, but barely spent any time. They are intriguing but I'd like hear of any actual projects people here have built that leverage and 'program' their own devices.
 

AnalogKid

Joined Aug 1, 2013
8,251
Lattice Semiconductor CPLD or FPGA:

FAA radar timing controller
Dual-port memory manager bus interface
VXI bus interface
cPCI bus interface and SSD manager
1024 x 4 SIM routing switcher
High-speed synchronous 4-bit 16-port data transfer system

ak
 
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Thread Starter

ApacheKid

Joined Jan 12, 2015
139
Lattice Semiconductor CPLD or FPGA:

FAA radar timing controller
Dual-port memory manager bus interface
VXI bus interface
cPCI bus interface and SSD manager
1024 x 4 SIM routing switcher
High-speed synchronous 4-bit 16-port data transfer system

ak
OK sounds pretty solid, mind if I reach out if/when I get around to exploring FPGAs?

Thx
 

ronsimpson

Joined Oct 7, 2019
400
CPLD is limited as to what it can do, but it is a God send for me. Often I have some large ICs and just need a couple functions more. (2input AND, 3 input OR, FF, two inverters, and a 3 bit counter) Small random support gates all fit into one IC.

FPGA has much less limitations. Anything digital can happen.
 

AnalogKid

Joined Aug 1, 2013
8,251
CPLD is limited as to what it can do, but it is a God send for me.
I shifted to FPGA's only because CPLDs were being discontinued. IMnsHO, the CPLD is the world's ultimate logic device, and is the near-perfect hobbyist platform for someone with a little money and even more time. Whenever someone asks about building a clock or event counter or whatever from scratch without a uC, I think CPLD. It is true logic circuit design but without most of those messy wires. The downsides are learning a new schematic editor and acquiring a programmer, so I rarely propose it as a solution. Still, great parts.

ak
 

Analog Ground

Joined Apr 24, 2019
271
I bleed Altera. I use FPGAs for high speed data acquisition and control. Custom interfaces, on-the-fly processing, buffering, etc. I have not used discrete logic except bus transceivers and clock drivers for decades. Throw in a CPLD. Beware of a somewhat steep learning curve for design entry, synthesis ("compiling") and simulation. The payoff is flexibility and being able to make changes easily. Once you get over the hump, you won't go back.

FPGA samples:
- 218 channel counter board for photon counting
- 200 channel DAC controller
- High frame rate image processing (5 kHz)
- Mirror control for adaptive optics systems
CPLD Samples:
- Inserting test patterns into data streams
- Microcontroller I/O expansion (lots of this)
 

atferrari

Joined Jan 6, 2004
3,634
So, how could I start with FPGA (skipping CPLDs, right?)

I am affraid of ending reading much more than actually needed. Happened to me in the past, many times.
 

Analog Ground

Joined Apr 24, 2019
271
So, how could I start with FPGA (skipping CPLDs, right?)

I am affraid of ending reading much more than actually needed. Happened to me in the past, many times.
FPGAs and CLDs are "two sides of the same coin". There is no good reason to start with one or the other. It depends on what you want to do with your designs and you won't know which until you jump in and get some experience. I can say this because there are newer device families which are blending traditionally CPLD or FPGA features together. So, no big deal. For example, FPGA look-up table (LUT) architecture (how the logical elements inside are structured) is combined with internal configuration memory which traditionally is only in CPLDs.

A more important decision is how do you want to enter your designs. Schematics? Hardware Design Language? If you want to start with schematic entry, find a development system which still supports schematic entry (not all do). Then, decide on the hardware. If you want to replace traditional discrete logic, I recommend going with a CPLD device. Start with lots of "macrocells" like 512 or 256 to give you lots of room to try stuff. Get a lower cost development board with some LEDs and general purpose I/O and go for it. For me, just reading is pointless. I have to have something to make jump. Here is a thought. Save the money on books and put it towards a development board. There is lots of free info to get started. Of course, download the free version of the development environment.

One hump is the cost of a "programmer". Get a good one affiliated with the device manufacturer. Don't worry about spending some cash. You have spent more on an o-scope and other bench equipment.

No matter which way you go, your experience will carry over into other types of devices and other development environments. It is not an earth shattering decision when you get started.
 

ronsimpson

Joined Oct 7, 2019
400
I have used Xilinx FPGAs. Love & hate but they are a big player in the market.

Not using Xilinx! SparkFun There are some small low cost boards and programmer here. I don't know much about them! For the cost of lunch you can have hardware.

BangGood Here is a large board for a low cost. ALTERA is a good option.
Xilinx Low end board I think it has the programmer built in.
 
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