FPGA in a Design

K

keith 21 years ago

SRAM based FPGAs have a non-volitile source for their configuration data. Typically this is an external serial ROM (the simplest, but most expesive), or a microcontroller with some sort of PROM. One can also program through a channel like a PCI bus.

There are other FPGA technologies that are non-volitile, though they're several generations behind the technology curve. SRAM based FPGAs are usually done on the same processes as microprocessors and have the advantage of that performance.

As above, one puts a "boot PROM" in the circuit. There are many was to do this.

Yes, though they're not the fastest nor densest parts. They're alos a PITA to use.

Generally, yes. It's not a big deal though. The FPGA manufacturers build several method of doing this into their devices. Depending on the design constraints, one is less painfull than the others. ;-)

Google "logic jump station". Also look at the Xilinx and Altera sites. There is a *ton* of information there.

Keith

Vote

J

Joshua K Drumeller 21 years ago

In college I had the wonderful and thrilling experience to design with FPGAs. I have learned a lot working with them. However, the FPGAs we were using were in pre-designed boards and we just focused on programming them with our assignments. My question is how do you incorporate an FPGA into a permanent design of a circuit board?

The FPGAs we used would lose their programming when the power was disconnected. So how would a circuit designer who wanted to use an FPGA in their permanent design get around that? Are there FPGAs which you can only once from a computer then solder it into a design? Or would you have to design a circuit which would load an FPGA every time it is powered up in your permanent design? Or something else?

I have been searching the internet for some time and most of the info I get is about FPGA experimental design boards. IF any one can help me out here it would be extremely appreciated.

Josh

Vote

M

Mook Johnson 21 years ago

Yes and Yes,

Actel make anti-fuse technology type FPGAs that you program and soler onto the board. Forever that parts will remain as programmed.

Actels ProAsc is a flash based part that you can program (even setup for incircuit programming for field upgrades) and change logic code when you need to. Flash retains its memory when powered down.

Xilinx makes FPGA that load their programming from a seperate EEprom which can be programmed and installed in a socket (8 pin dip) for reprogramming.

Altera is similar.

Lots of options.

Vote

K

Ken Smith 21 years ago

In article , Joshua K Drumeller wrote: [....]

You can:

(A) Never disconnect the power. Using a lithium battery or the like, the power can be left on. This is an insane thing to do unless you are very worried about security.

(B) Use a FPGA that loads its data from a PROM that sits next to it.

(C) Use a FPGA that has a PROM co-packaged with it.

(D) Use one of the anti-fuse or the like ones.

(E) Load the code from a micro controller.

-- kensmith@rahul.net forging knowledge

Vote

FPGA in a Design

Join the Discussion

Didn't find your answer?