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Welcome to Lafferty in this video I'm going to show you the complete isolation of the universal shift

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register should look like on the base to bored.

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Now if you have one or two don't worry on like this and I'm here to help.

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I'm more than happy you just send me an e-mail and let me know.

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This is probably a little bit more difficult but that's OK.

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That's the way I designed it was.

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I want to struggle a little bit.

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But if you're saying they're spending I don't want you to be frustrated.

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I want you to learn and that's the best way of learning is actually doing so.

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These labs are designed to have it so you have to understand the code.

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If you're ready let's grab your board let's go.

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All right.

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Here in lab three.

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Here is the universal shift register running on my basic toolbar.

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Now with the passing of the file that I gave you the inputs that are mapped are you've got an output

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which is eight minutes long which is represented by these eight ladies on the front of your base is

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two board right here and then you've got your input as your slight input which is these two switches

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on the far left over here and you've got your input which is the same as has a shift register in the

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previous line.

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Is this for switch over here and you've got the clock which is represented by this button right here

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and the reset which is indicated by this button over here.

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Now the way universal shift register works is very similar to the shift register except that with the

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universal shift register you can select if you want to shift to the left or do you want to shift to

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the right or do you want to load data and it's like a shift register.

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It's the same this or Friendster you just have more options.

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So you get demonstration here.

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So right here I've got these two select inputs are basically telling my shift register what I wanted

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to do right now they're both zero.

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So that is indicated as a whole where nothing happens.

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So if I click a button there nothing happens to it.

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Now if I push them both up right here I'm going to load the data bit and which is represented by just

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what's right here which is low right now.

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So if I push it you don't see anything because I'm losing zeros seemly now.

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Oh I hadn't thought of that up.

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And as soon as I was that button there you'll see a data represented by the light so if I push it again.

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It's basically a key so there are now five percent down to zero and go to zero in there and it turns

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that whole idea off.

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So let's go ahead and loaded it a bit and the shift register.

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OK.

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So when it had low then and now our select here we can determine if you want to shift to the right or

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left.

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If we shift to the right.

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This is basically going to fall off and go away.

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So we want to shift it to the left.

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So in order to do that we need to have our select before right one down what the far left one up but

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push that button you see a shift in over one and every time increase that call button it shifts over.

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Now if I'm on a ship at the fairway I go ahead and if I put them both down it's a whole where nothing's

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going to happen and push that button that it just stays there.

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But I would push them both up.

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Then go ahead.

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A lot of data that in which you see there lives in.

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And now let's say I want to continue shifting them down like so.

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OK now I shifting to the right.

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I just talked a lot down talk my selection of an old title over an ugly scene there.

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If I keep going.

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As soon as they get off the edge of your Ellet either that is kind of fall off and go away.

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That's because if you look in the code you're actually giving it a zero.

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As soon as it shifts out so it goes through and it clears out.

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Now here we have a reset which Let's go ahead and load some data and go to hit that target on and then

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you got to shift it down to that shifted in there which is a lot more operations but typically you would

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have something like inside your FPGA cube.

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You would have a clock and other things you'd have control things like that.

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And this clock we're just putting all these buttons and it switches so you can actually see and understand

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what's going on here.

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So give him a reset once again nothing happens.

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That's because a reset doesn't occur.

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It happens on a clock cycle.

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So I have to hold down my reset and press the clock and that's how you clear it which you can see that

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in the code.

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There's a piece of code there it's a process that is evaluated on a clock cycle.

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So for example some more bits in real quick and will explain how what was going on.

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OK so I've got three bits here and I clear them.

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If I hit the reset nothing's going to happen because that block of code there there's no the clock cycle

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hasn't happened yet so it's not being evaluated in that process.

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So if I want that to clear out the hold the reset down which is a logical one.

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So you see in code it says on the rising edge of clocks says I push this on the rising as the clock

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is going to evaluate that process and what that process does is always these values is zero.

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So the process is evaluated and your all your Ltds are clear.

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Now if you're not getting this on your board and you are lost or are struggling don't worry.

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I have a solutions manual on there that you can look at you know go through and explain how step by

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step how to get this to simulate Mollison and how to get it to run on this board.