Learn Digital Electronics using Schematics & FPGA Boards

This lesson will show you the steps to download and install ISE on your machine. You will have to go to download section of Xilinx.com  and download ISE  14.7. This is the last version of ISE which support Schematic Design entry. Once ISE Webpack is installed, you will need a license to use the software.

You will learn how to get a free license for ISE Webpack. This will allow you to use ISE perpetually for certain devices, including that on the Basys2 board. This license allows the use of the full flow of ISE.

Since you will use ISE in this course, it's good idea to know how to get around in the Project Navigator. You will learn how to open, save, add new sources, create a new course, archive etc...

This lecture will show the typical gates used in digital electronics and they are:

(1) OR, 

(2) AND, 

(3) XOR, 

(4) XNOR, 

(5) NOR, 

(6) NAND

This lesson shows how to implement a single logic gate, which is the XOR on the board. It will be a very simple design with one gate and ports. Once loaded on the board, you will be able to test it using LEDs.

In this lesson we will see how to implement a more complex design made up of multiple interconnected gates. The design will be implemented on the board and will use the switches for input and the LEDs to indicate output.  

Registers or Flip Flops are important building blocks in digital circuitry. They are mainly used to store information in the form of bits. Most Flip flops will be used synchronously with the clock. In this lesson we will implement a simple FF on the board.

In this lesson you will learn how to use a basic Data FF on an FPGA. You will see how it works on hardware.

We will introduce the concept of Clear and Enable in relation Flip Flops (FF). If a flip flop has a clear pin, a HIGH value will normally clear the state of the FF to ZERO. When the clear pin is LOW, it will have no effect on the FF and so it would work normally. 

Enable line is to enable to FF to work normally (when Enable=1) or stay unaffected by the clock (when Enable = 0).

Shift Registers are useful piece of circuitry for buffering data, pipelining and more. We will connect individual Flip Flops to build a Shift Register and see it work on hardware by shifting some data in. 

Since a push button is slow, push it down will create a pulse of several period cycles. A debouncer circuit has the job of outputting a single pulse from a push button. It consists of three registers and ANDED outputs. 

In this project will add a debouncer circuit as a symbol and use it to feed the Chip Enable of the Shift Register (SR). This will allow us to see the shifting of bits into the SR by pushing the push button on our board.

Using selector lines of Multiplexers can allow specific input to go through the multiplexer in real time on hardware. If the number of selector bits are n, then the number of input lines would be 2 power n e.g 3 bits selector will control up to 8 input lines

You will see how to Implement a simple Multiplexer on the FPGA Board. You will use the Mux to select which input will go through to the output using selectors.

In this lesson you will learn the concept of Binary Counter. In the binary world, numbers are only represented with 1 and 0's.

In this lesson you will learn how to build a basic counter easily and see it increment using LED's on the board

The Xilinx Symbol Library has adders and subtractors that can be used to add/subtract two numbers in binary.

We will implement a simple adder on the FPGA using binary numbers. We will verify the adder on hardware against a calculator.

RAM's are Random Access Memories used to store temporary data. The data in the RAM is volatile and so cannot be stored when the power is off on the board. You will learn about the normal connections to a RAM and how are data structured in it.

In this lesson we will implement a RAM on hardware, store some data, then retrieve the data when needed.

It is common to use states to define an electronic system. For example: an alarm can be in a state of 'no alarm' or 'alarm' or 'stand by' etc...State Machines are very useful piece of electronic circuitry used to store information about States. In this lesson you will learn how to describe and design state machines.

There are two main types of States Machines: (1) Mealy and (2) Moore. 

In this lesson we will implement the state machine that we described in the previous lesson on an FPGA. We will check how the state changes with different sequence of input.

In this lesson, the State Transition Table will be derived and explained

From the truth table, the Transition and Output Logic will be designed and we will confirm that the derived logic match that of the project for this alarm.