What I expect to find is a block diagram with the, um, with the Matrix arrangements, the bars matrix
of the microcontroller.
And this should inform me where you are connected.
This was it.
This is familiar.
You've seen this before.
Okay.
So I'm going to zoom in.
Okay.
Let's see.
Come down here.
But let's zoom in further.
Can't you see you, Art?
Okay.
I see you.
Okay.
You saw it.
It's written.
You saw it here.
And this the same you said.
Stands for Universal Synchronoss, asynchronous receiver transmitter.
When we are using just the asynchronous pit, we call it you art without the S..
So that's the same thing.
This just tells us we can have Synchronoss or asynchronous in a way.
This was you saw one and this was connected to the APB to bus.
Okay.
Parbo, you said to me, you said two is connected to the APB, one bus.
Okay.
You said two is the one that the nuclear body uses.
So if we use use two, we can try this by simply using the USP, the US Connector of the New Clue.
Whereas if we go and initialize a different use it we may have to connect on exten or, you know, USP
connector to those pins.
So for our experiment sake, we are going to use this one over here.
But certainly after this lesson, I expect you should be able to expand the library so that you can
use any use that you want.
But this one is going to be customized for user, too.
And your assignment will be to do it for use at one.
And let's see if we have about I use it here, which you put out.
The microcontroller has just one and two.
Okay.
No problem.
So we know this was connected to the APB, one bus.
Um, we have two documents.
The data sheet.
The reference manual.
All right.
Let's see.
Come over here.
I'll go to page 149 of the.
Of the datasheet, page one for tonight.
See page 114.
Yes.
Page 149.
But off the reference, mind or not, the data sheet.
So on forty nine, there should be information that with alternate functions or just head the page over
here.
Hytten 149.
Okay.
Yeah, we are.
Right.
So for those of you who know some digital electronics, you see this symbol here, the schematic symbol,
you know this a multiplex.
I mean, and we've got these number of inputs and we can only have one outputs.
And this here is the address that allows us to select one of these outputs.
We've got a F zero, a F one here, too, all the way to a F fifteen.
And this is what we call the alternate function.
Registar law heads, we have the R l over here, and then we have alternate function registe the high
as well, which also starts from here.
So no function registered law is for totally and or is for dealing with PS number zero seven of our
ports.
If we are working with a GPL, you pin eight through fifteen, then we would have to access the alternate
function register high.
So like we said, a war, our rexon t xp and so connected to p h twenty three respectively.
So they are between zero and seven.
That is why we are dealing with alternate function.
Register low.
In a way, the driver remember our alternate function now registe, a member, is an array with two
unary which to element zero and one, the first element stands for the alternate function registered
low, and the second element is the alternate function register.
OK, so over here, when you check it says a F seven is for you, Sutt one and two.
Right.
Is for use that one into.
What does that mean.
Now let's go and see what a F seven means.
Think it should come back to page fifty nine or something to be a F register.
Let's see what's alternate function register.
Okay, here we go.
Right.
So that's the alternate function register.
And we have alternate function low as well as alternate function.
High register.
Right.
And like I said, are the same.
If you are dealing with penis numbers zero through seven.
Then you should be using the alternate function low and then eight through fifteen alternate function
register.
Hi.
OK, let's see.
OK.
So this is a F seven, f seven means.
Zero means one one one zero.
Remember, we need four bit to figure out the alternate function.
So you can see in this alternate function registe that law bits through.
Three, four eight f zero bits, four through seven hour for a F one.
I shouldn't say that.
Actually, there's a better way to understand it bit.
Sue two, three, four.
All pins.
Zero.
Of energy.
You put A, B, C, D all the way to H.
Bit bits.
Bits four through seven.
Apple are for all P ones.
And these these next four bits are for all pin tubes.
And then these next are four open threes like that.
You have this apparatus here.
Right.
Okay.
So we are using we are using a two.
We're going to test out transfer to X over Y.
You are to be a two.
So this over here is four will be for a zero.
This over here will be for P a one.
And this over here will be for P a two.
So we would have to write one one one zero here in the a f r l register.
Right.
And one one one zero.
That is our e f seven.
We have to write a F seven in this position from bits number eight through bits.
Number eleven, we have to write one one one zero.
Okay.
To configure it for our T x.
So if you expand this, you realize that this hexadecimal number and each hexadecimal digits corresponds
to four binary digits.
So this over here is the first four which in our data sheet would correspond to these first four.
Right.
And then this next one here will correspond to the next four.
Right.
And I was seven here.
If you expand the seven hexadecimal, you end up with one one one zero.
And this would be perfectly placed here.
Hence, we have this.
Right.
Okay.
I know you get it now.