Anyone has experiences with GAL/PAL programming ?

[Madmartin]

Hello, forum !

I just want to figure out a nice way to program Gals/Pals by myself.
I've got a GALEP3 programmer - yet it is unclear how
to submit the data that is to be programmed.

What I'd like most would be some personal opinions and roads that you
went down by yourself, already.
I also know that there are plenty DIY programmers available at
google.com, but I don't want to build every and all of them just to try out
what's good and what not.

I'd also love to get a hint on PAL programming as I stumbled over a thousand of those thingys for free. Just I don't find anything suitable for programming them.

Thank you very much,
Martin

 

[Scubasteve]

Hi Martin,

You say that you do have the GALEP3 programmer, is that correct? If so, why would you try to build or even look for other programmers? You already have one suitable to program all of the devices supported for that programmer. You will need to decide which device you want program from that list, then you will see the limitations involved (ie. speed, number of gates, I/Os, etc.).

Then, you will need to find some sort of compiler to generate the internal logic. Actually, you will need to know which logical functions you want to make first, then get it into code. Example, you can make a BCD to gray code converter, or a johnson counter, etc.

There are two flavours of compilers for any PLD. Graphical and written code, both have advantages and disadvantages. I prefer entering the data in graphically, so I do not need to learn a language to do so. You basically connect a bunch of gates supported by the device and compile it. It will tell you if there are too many or whatever errors you have..

You can also learn languages to describe logical function, these include ABEL, Verilog, VHDL, etc. A simple boolean expression can replace a very large amount of gates, which would be faster then putting it together with logic symbols.

In both cases, most dedicated software comes with an algorithm to minimize the amount of gates needed to perform the requested function. This is sort of like using Karnaugh mapping to minimize a logic function, but much more sophisticated.

www.quicklogic.com
www.protel.com
www.altera.com
www.xilinx.com

Look around these sites and get a feel for PLDs, you will learn a lot. Remember, you don't need a 468pin BGA to start out programming, you would want a 14-20pin device to play around with first to learn.

Goodluck!,

Steve