Project 3: Guess the Logic

In this project, you will download a bit file to your board to configure the FPGA with four different logic circuits. The circuits use buttons and switches for inputs, and LEDs for outputs. You must probe the logic circuits by applying all possible combinations of input signals. From the results of applying all possible combinations you will be able to write logic equations that describe the circuits' behaviors. You will then rewrite the equations using Verilog HDL and re-implement them on FPGA and compare the circuit behavior with the given bit-file.

FPGA Circuits

Project 4: Majority of Five

How could you find a majority of the vote if each voter of five has a switch to vote for yes or no? The logic is fairly simple and will be used in this project. Any time there are three or more of the five who vote yes, then there is a majority and the LED needs to turn on.

FPGA Circuits LEDs

Project 5: Multiplexer, Decoder, Encoder, and Shifter

In this project, you will design a multiplexer, a decoder, an encoder, and a shifter using Verilog HDL. Instead of building the circuit using logic operators, you will learn to describe a circuit behaviorally according to the functionality you wish the circuit to perform.

Circuits Verilog Logic Basys2 Nexys

Project 7: Simulate Glitch and Delay in Combinational Circuits

In this project, we are going to examine the delay in combinational circuits. We are going to tell the simulator of the delay of each gate in Verilog and simulate the circuits to see how delay can affect the behavior of a combinational circuit.

Circuits Delays Verilog Basys2 Nexys

Design Challenge 4

In this design challenge, you are going to finish a seven-segment decoder circuit that can can drive the 4-digit 7sd device on the Digilent board. We will take a hierarchical design approach to this problem, and the modules you designed in this design challenge will be reused in other projects as well.

Circuits 7SD Adept Basys2 Nexys

Design Challenge 7

In this design challenge, you are going to be asked to put combinational circuit, sequential circuits and state machine together and design a stop watch on the FPGA board.

Circuits Stopwatch Basys2 Nexys

Propagation Delays

Time is required to process information in digital circuits. This processing time is divided between the less significant signal transmission time, and the more significant propagation delays associated with switching logic circuits. If not managed properly, propagation delays can result in logic circuits that run too slowly to meet their requirements, or that fail altogether.

Circuits Delays Adept Basys2 Nexys

Signed Magnitude and 2's Compliment

Digital circuits that perform arithmetic functions often must deal with negative numbers, so a method of representing negative numbers must be defined.

Circuits Adept Basys2 Nexys

Arithmetic and Logic Units (or ALUs) are found at the core of microprocessors, where they implement the arithmetic and logic functions offered by the processor (e.g., addition, subtraction, AND'ing two values, etc.). An ALU is a combinational circuit that combines many common logic circuits in one block.

FPGA Circuits ALU

Memory circuits function by storing the voltage present on an input signal whenever they are triggered by a control signal. They retain that stored voltage until the next assertion of the control (or trigger) signal. Between assertions of the control signal, the input signal is ignored and the output is driven to the most recently stored voltage.

FPGA Circuits

Although combinational logic circuits form the backbone of digital circuits, sequential circuits are used in the vast majority of useful devices; there are more than 100 billion in existence.

FPGA Circuits

The most difficult task in designing sequential circuits occurs at the very start of the design; in determining what characteristics of a given problem require sequential operations, and more particularly, what behaviors must be represented by a unique state.

FPGA Circuits

A state diagram with state codes and complete branching conditions contains all information required for the design of optimal next-state and output logic circuits.

FPGA Circuits Logic

Electric Vs. Electronic, Analog Vs. Digital

A collection of electronic components that have been assembled and interconnected to perform a given function is commonly referred to as a circuit. Electronic circuits can be divided into two broad categories: digital and analog.

FPGA Circuits Digital Analog

Physical circuits are constructed of real, physical devices. Physical circuits can be inspected, tested, and modified. They consume electric power when energized, and they can function properly and do some meaningful work, or they can malfunction and create serious hazards to health and property. Model circuits are built on a computer and simulate the workings of the circuit, which allows for testing before the physical circuit is created.

FPGA Circuits

Slide Switch, Push Button, and LED

Circuits often require inputs that come directly from users (as opposed to inputs that come from other devices). User-input devices can take many forms, among them keyboards (as on a PC), buttons (as on a calculator or telephone), rotary dials, switches and levers, etc.

FPGA Circuits LEDs Switches

The Base for Electrical Components

Electronic components are often assembled and interconnected on a flat surface known as a circuit board. The several types of existing circuit boards may be divided into two broad categories: those intended for prototype or experimental circuits, and those intended for production and/or commercial sale.

Circuits Hardware Electrical

A collection of one or more gates fabricated on a single silicone chip is called an integrated circuit. Here we will discuss the elements of an integrated circuit and how those element function.

Circuits IC

A digital circuit is constructed of a power supply, devices, and conduction nets. Some nets provide circuit inputs from the “outside world”; in a schematic, these input nets are generally shown entering the left side of component and/or the overall circuit.

Circuits Digital

Information Representation in Digital Systems

A signal in a digital circuit is a circuit net that transports an output voltage from one device to one or more input connections of other devices. In a digital circuit, signals are constrained to be at one of two voltages, either Vdd or GND. Thus, all data in digital circuits are represented by signals that can be in one of only two states, and all data operations combine two-state data inputs to produce two-state data outputs.

Circuits Digital

A digital circuit represents and manipulates information encoded as electric signals that can assume one of two voltages: logic high (Vdd) or logic low (GND). Here we will dig further into the workings of digital circuits now that you have a better foundation for understanding.

Circuits Digital Logic

Behavior Definition and Schematic Representation

Combinational logic circuits use networks of logic gates to produce outputs that change in strict relation to input changes; that is, an output can only change state immediately after an input changes state.

Circuits Logic

The XOR function is frequently used in digital circuits to manipulate signals that represent binary numbers.

Circuits Digital XOR XNOR

Efficiency of Different Implementations of Same Logic Functions

A digital logic circuit consists of a collection of logic gates; the input signals that drive them, and the output signals they produce. The behavioral requirements of a logic circuit are best expressed through truth tables or logic equations, and any design problem that can be addressed with a logic circuit can be expressed in one of these forms.

Circuits Digital Logic