Want to get started with CPLDs

[saad87]

I want to get started with programming CPLDs. However, I'm confused about which development kit to get? I have about $200 to spend. I feel that Altera has slightly better software - their Web version is free, it seems. So I'm mostly interested in that but have my options open.

I'm also wondering weather I should initially learn VHDL or Verilog? I've found a great book, titled Digital Design with CPLD Applications and VHDL. I'm finding the book easy to understand and this is important to me as I have very little experience with HDLs. But I did take a course in Handel-C for FPGAs when in school - though I'm not sure how helpful that will be.

Any suggestions on how to get started would be appreciated.

 

[yungman]

Most jobs I saw asked for VHDL at the time, I would go with VHDL or whatever more popular now as I have not been in the job market for 6 years. I used to be very good with AHDL and Quartas 6 years ago, but I did not see much demand of this at the time.

To get started, I got the free version and start reading and programming! It is very easy, it's like any programming languages PLUS simple digital electronics like FF, gates etc. Only thing you have to watch out is not to drive the Preset and Reset of FFs with a combinatorary signal ( From a multiple input gates that input from different sources.) as glitch will cause problems. This is the most common mistakes even from experience engineers that work with CPLDs. I had to trouble shoot for my engineer and even a contractor. The problem occur very infrequently and is very hard to pin point.

Start small and then go into modular design just like programming. If you know any language, you can learn it in like two to three weeks. Easy.

 

[saad87]

Yes. Learning the language doesn't seem to be a difficult task. I have experience in programming C and Objective-C.

What I'm really confused about is the development kits.

 

[yungman]

Yes. Learning the language doesn't seem to be a difficult task. I have experience in programming C and Objective-C.

What I'm really confused about is the development kits.

Get the one that has more jobs, don't try to save money. This is no time to worry about who is cheaper. It is not going to help you if you get the Altera development kit and learn everything and the jobs call for VHDL! I had no choice at the time because the place I worked for use Altera and AHDL. Let the market determine which way you go.

Yes learning is very easy, just remember the Preset and reset I talked about. That is such a common mistake and is so deadly. You ALWAYS need to qualify ( waste one DFF to clock the combinatory signal through to deglitch it) the signal for the Preset and Reset. CPLD is not exactly like programming, it is hardware. Also I did a lot of timing and propagation analysis because it is actually hardware that has real time delay. They do have setup and hold time requirement so you have to do propagation calculation when you do programming.