Walk over to the VHDL did type introduction and this lecture I'm going to introduce the different datatypes
associated with the HGL.
First we have data classes which are used to describe the data types based on data class will limit
you or allow you to do certain things with that specific data type.
So the day classes are we have constants signals variables and files.
So with constants at a high level they are a value that can never change.
A signal is a value that is constantly changing inside of your design and a variable is something we
use to help you construct your designs and files our views and test benches to help you simulate and
verify your design is working properly.
The data types we have here are a number of data types we'll be using in the HDL.
We have a standard logic standard logic vector and unsigned signed integer and a boolean data type.
Each data type is associate with that data class except for files.
Those we're using for simulations only.
So for example we had the constants and the signals.
So I could have a constant That's a standard logic and I could have a signal that the standard logic.
And based upon the different types if it's a constant state in logic it can never change or it's a signal
standard logic.
Now that value can change.
So based upon the data types and the data class that you're using it will dictate what you can and can
do with that specific signal or constant or whatever you are you're working with the kind of help you
create your designs.
So why do we use data types inside of an FPGA.
Everything is a one or zero.
Just like a computer.
Well the reason wreathing data types is this allows us to group these ones and zeros in a way that's
easy for us to understand.
If we see a group of one and zeros inherently to the human eye it just doesn't really make a lot of
sense.
It's hard to understand what's going on.
But if we can see a number like say ninety nine 100 101 102 to us it's easy to tell it OK.
That number is counting.
And so that's the reason we use data types.
It helps us group these ones and zeroes so we can make our design happen in a way that's understandable
to us humans that the computer or your FPGA can then interpret and execute these commands enough talking
about the data types.
Let's actually learn the specifics.