Just how much of the HDL do you need to know?

[hamster]

I realize I only know a tiny corner of all of VHDL.

I know little about creating packages, libraries, other data types outside of 'std_logic' and 'signed', 'unsigned', 'integer' and 'natural', things like "a <= b after 10 ns;", string handling, file handling, structures, text I/O ..... the list goes on and on.

Just how much of VHDL do you need to work with FPGAs? My guess is about 20% 

And once you get that far, is it worth learning more?

And is Verilog the same?

And does anybody have any recommended resources on more advanced VHDL?

[mwingerson]

Hey Hamster,

Those are great questions.  I am far from an expert but probably have enough experience to chime in.

I realize I only know a tiny corner of all of VHDL.

I know little about creating packages, libraries, other data types outside of 'std_logic' and 'signed', 'unsigned', 'integer' and 'natural', things like "a <= b after 10 ns;", string handling, file handling, structures, text I/O ..... the list goes on and on.

Just how much of VHDL do you need to work with FPGAs? My guess is about 20% 

Assessing how much HDL a person needs to know before they can work with FPGAs is a hard topic.  A class at WSU has students start at AND gates and finish at a stopwatch and a VGA controller.  So they have enough HDL and digital logic to be able to accomplish some pretty cool designs.

With a small amount of HDL knowledge, some real applications can be created.  This leads me to think that the HDL is a fairly minimal skill compared to the amount of knowledge that goes into designing the and debugging the hardware.  Knowing generics in VHDL doesn't help much if you don't know what a mux is (assuming most designs have a mux and a bit of an exaggerated example)

Back to the original question, I learn something new every time I write code so I don't know if I can accurately measure how much of the language I know.  I agree with you that a ridiculous amount of utility is learned very early in HDL but is limited by the familiarity with the components that are frequently used in FPGAs (counter, mux, ram, etc)

And once you get that far, is it worth learning more?

There is some serious cost versus benefit to weigh out but I always think learning more about the language you are using will benefit overall.  That may just be me.

And is Verilog the same?

Yep, I think the entry level knowledge is equivalent.

And does anybody have any recommended resources on more advanced VHDL?

I don't think there are learning resources for advanced HDL.  I have learned most of what I am now doing from reading other people's code and seeing other implementations.  If you have a topic of interest, I can see if anybody know of any resources for that.

Thanks for the questions,

Marshall