Verilog or VDHL.

[mrpackethead]

I'm about to dive into learning FPGA's.    It seems its almost a religous level war, if you choose to use Verilog or VDHL..   

Any suggestions about a path to follow.

[ataradov]

Try both, see which one you like most.

I personally like Verilog. VHDL is far too verbose for me. On the other hand, VHDL has some nice features that were only added in SystemVerilog. But with SystemVerilog, you basically get all you will realistically need.

Just anecdotally, I see more Verilog in the industry.

[langwadt]

Try both, see which one you like most.

I personally like Verilog. VHDL is far too verbose for me. On the other hand, VHDL has some nice features that were only added in SystemVerilog. But with SystemVerilog, you basically get all you will realistically need.

Just anecdotally, I see more Verilog in the industry.

afaict it is also a regional thing, Europe mostly VHDL, USA mostly verilog

[jmelson]

I'm about to dive into learning FPGA's.    It seems its almost a religous level war, if you choose to use Verilog or VDHL..   

Any suggestions about a path to follow.

It ** IS ** a religious war!
If you think of FPGA design like coding a program in C (big mistake) Verilog looks real comfortable, but that leads you into a fallacy.
Verilog does a lot of type conversions, etc. on the sly, and these can bite you.

VHDL requires you to specify any type conversions where there could be unpleasant side effects, but will do certain ones where it is deemed safe.
I really have not seen VHDL as being more verbose IN THE THINGS that I tend to do, so it doesn't bother me.  I do admit if you are doing numerical algorithms (digital filtering, image manipulation, cipher work, etc.) then Verilog may be much better to express it, but if you are doing state machines, registers, address decoding, etc. then I find VHDL works fine, too.

Jon

[nctnico]

IMHO it is more important to use a HDL to describe what functionality you need instead of thinking in logic and feed that to the synthesizer. Thinking in logic and thus taking over the job from the synthesizer is like using inline assembly in C to create a program. Whatever HDL you use, it will be much harder to work this way. Just like using inline assembly building the logic yourself is only necessary where size and/or speed really matter.

Unfortunately there are very few examples floating around that really use the power of an HDL. Most just approach problems in a dumb & very verbose way which ends with writing an endless amount of code with a lot of nearly similar lines being repeated over and over. For fun Google a priority encoder in Verilog or VHDL. 9 out of 10 write a single line for each input condition    Like any programming language a HDL will take time to learn on how to use it's full potential.

[ataradov]

The reason for this is that HDL tools (at least for FPGA) suck at inferring stuff. And the worst of all, they suck differently for different vendors. So in many cases you have to write strange code that you would not otherwise.

This is especially frustrating with memories and trying to get tools to infer BRAMs. Altera is horrible at it.

[NorthGuy]

I'm about to dive into learning FPGA's.    It seems its almost a religous level war, if you choose to use Verilog or VDHL..   

Any suggestions about a path to follow.

Doesn't really matter. Try both and see what you like.

[martinayotte]

It seems its almost a religous level war, if you choose to use Verilog or VDHL..   

As other mentioned, I personally think that Verilog is more concise and more readable, but if you need sometime some opencore included in your project, sometime you can't force original author to publish it in Verilog. So, your project will then need to mixed both ...
It is up to you to choose in which language the top level will be ...

[rstofer]

It's kind of like Pascal vs C.  Yes, Pascal is relatively verbose but the upside is it won't let you shoot yourself in the foot.  C doesn't provide much in the language to prevent mistakes and, instead, relies on the programmer to know what they are doing.

I started with VHDL and I'm going to stay with VHDL.  Every time I look at Verilog I just get confused.  I'm sure the reverse could be true for others.

The other side of the deal is that had I started with Verilog, I would probably find VHDL wordy.  In the end, you probably need to learn both languages (or substitute SystemVerilog for Verilog) and you should probably alternate between projects.  Or even in the same project - it should work!

One of the big contributors on this forum is hamster_nz.  Look at his wiki for examples of VHDL code.

http://hamsterworks.co.nz/mediawiki/index.php/Main_Page

[mrpackethead]

I have some project ideas in mind but am wanting to explore, that will probably require devices that are bigger and more complicated.    I saw on crowdsupply.com some EasyFPGA modules, using the LatticeXO-2 IC's, which were very low cost.   Thats interesting for another reason as they may be useful for some other projects, but also, its a very low cost investement.

What would you recommend if you had a budget of $500 to buy some dev boards / tools etc for starting out.

[james_s]

Try both. I personally prefer VHDL and find Verilog to be a bit to abbreviated looking and hard to follow. In the end it doesn't really matter though, both languages have identical capabilities, you can infer exactly the same logic with either one.

If I had $500 to spend, I'd buy a $15 Cyclone II FPGA dev board and USB programming cable and save the other $480 for more advanced stuff once I was proficient. It was a couple years before I was making anything too big to fit in the cheap boards and I still use them in a lot of projects because they're good enough to fit a complete 8 bit ocmputer in the FPGA and they're cheap.

Do you know what you want to make?

[mrpackethead]

I've got some LED driver projects, which are quite simple.  ( but do not scale well with microprocessors )...

But What i want to do, is some projects with SDI video and IP over ethernet.

[james_s]

Video will take a bit more, but you should be able to get a suitable FPGA dev board for <$100 that has HDMI or other LVDS ports on it, many have ethernet too. Either way something cheap will get you started and by the time you run out of resources you'll probably have a pretty good idea of what you need.

[mrpackethead]

the lattice XO2 on paper looks attractive, as i dont' need to attach anything next to it, to make it useful.. Thoughts?    Lattice, altera? Xilinx?

[ataradov]

Altera MAX10 does not need anything either.

[james_s]

Try the software, that's the important part. Those are the big three FPGA vendors, Lattice is a distant third in terms of hobbyist use/support. They all offer parts with similar capabilities, and in all cases you are stuck with the software package provided by the vendor of the parts you choose to use.

Nice thing about HDL is you can write rather platform agnostic code so porting between FPGA vendors/families is quite easy.

[mrpackethead]

Try the software, that's the important part. Those are the big three FPGA vendors, Lattice is a distant third in terms of hobbyist use/support.

Don't intend to be doing this as a hobby.   What makes their software third?

They all offer parts with similar capabilities, and in all cases you are stuck with the software package provided by the vendor of the parts you choose to use.

whats similar to somethign like an XO2-1200       ( i was lookign at the 32 pin one, in a QFN package )..

[hamster_nz]

I've got some LED driver projects, which are quite simple.  ( but do not scale well with microprocessors )...

But What i want to do, is some projects with SDI video and IP over ethernet.

For SDI at any decent speed you pretty much have to engineer/design own board - you need to use high speed transcievers, add line drivers, and set up the required reference clocks.

IP (usually UDP) is relatively easy. TCP/IP requires a lot of resources and is a very complex protocol (e.g. MTU path discovery, slow start, fragmentation, retransmits...). TCP is best left to a (either hard or soft) CPU.

[martinjaymckee]

If this is just for your own projects, I would absolutely suggest (with everyone else!) that you try them both out.  I did that when I was starting out and I am very glad that I did.  They both have strengths.

Cheers,
Martin Jay McKee

[iMo]

My own stuff is written in verilog. As there is a lot of open source VHDL code you have to understand VHDL as well. Soon or later you have to mess with both.

[mrpackethead]

For SDI at any decent speed you pretty much have to engineer/design own board - you need to use high speed transcievers, add line drivers, and set up the required reference clocks.

I'm wanting to insert and remove the audio channels that are on the SDI.   Semtech make some all in one front ends for the SDI, which look like a good starting point.    For most systems the audio will turn up as either AES digital or Line level Audio.   What i want to do is take the audio and use it as a Dante  ( AoIP ) source.  ( or insert dante based audio ).

IP (usually UDP) is relatively easy. TCP/IP requires a lot of resources and is a very complex protocol (e.g. MTU path discovery, slow start, fragmentation, retransmits...). TCP is best left to a (either hard or soft) CPU.
[/quote]

[AG7CK]

This reminds me of the test equipment forum: An amazing amount of people find it necessary to ask which oscilloscope THEY should buy - even if there are hundreds of posts on all instruments already.

Here are 100+ posts from 2016: Verilog or VHDL?

https://www.eevblog.com/forum/microcontrollers/verilog-or-vhdl/

(Easily found by the string "site:https://www.eevblog.com/forum/ verilog vhdl" or similar in a web search field.)

[mrpackethead]

This reminds me of the test equipment forum: An amazing amount of people find it necessary to ask which oscilloscope THEY should buy - even if there are hundreds of posts on all instruments already.

Here are 100+ posts from 2016: Verilog or VHDL?

https://www.eevblog.com/forum/microcontrollers/verilog-or-vhdl/

(Easily found by the string "site:https://www.eevblog.com/forum/ verilog vhdl" or similar in a web search field.)

Thanks for such a useful post.  Strangley enough i'd already read most of those.  There have been quite a few folks quite happy to discuss the topic.   Your welcome too.  Whats your preference verilog or VDHL AG7CK

[NorthGuy]

Lattice, altera? Xilinx?

You can start from software. They're all huge and slow. Install all the tools. Select the one you like the most (or hate the least). There are lots of things you can learn before even buying a board. You can do simulations. You can build example projects and see what size FPGA you may need - it's nearly impossible to figure out before you start.

[dmills]

So you just want a de-embedder and AoIP output?

Dante will cause you problems because Audinate keep some bits closed, but AES67 should be workable (Or ST2110-30, pretty much the same thing), and AES67 will interrop with Dante in at least some Brooklyn II versions.
For 3G-SDI stuff something like an Artex-7 is a good fit, having the transceivers you will need, and Yea, Semtech or TI for the line equalisers.

The elephant in the room with that project is clocking, because unless the SDI and PTP clocks are locked to the same reference you will need an ASRC core in there to avoid glitches. Also on the subject of clocking make sure you connect a suitable clock generator for the transceivers and SDI processing, 148.5MHz and 148.35MHz  are the conventional choices for 274M video, SIlabs parts are the common answer.

Regards, Dan.