Key Terms
Lesson 1.1
Analog
A way of representing some physical quantity, such as temperature or velocity, by a proportional continuous voltage or current. An analog voltage or current can have any value within a defined range.
AND Gate
Digital circuit that implements the AND operation. The output of this circuit is HIGH only if all of its inputs are HIGH.
Breadboard
A circuit board for wiring temporary circuits, usually used for prototypes or laboratory work.
Capacitor
An electrical device used to store electrical charge.
Clock
Digital signal in the form of a rectangular pulse train or a square wave.
Combinational Logic
Digital circuitry in which an output is derived from the combination of inputs, independent of the order in which they are applied.
Conventional Current
The direction of current flow associated with positive charge in motion. The current flow direction is from a positive to negative potential, which is in the opposite direction of electron flow.
Current
A movement of electrical charges around a closed path or circuit.
Cycle
A series of events that are regularly repeated in the same order.
Datasheet
A printed specification giving details of the pin configuration, electrical properties, and mechanical profile of an electronic device.
Digital
A way of representing a physical quantity by a series of binary numbers. A digital representation can have only specific discrete values.
Digital Waveform
A series of logic 1s and 0s plotted as a function of time.
Digital Multi-Meter(DMM)
A piece of test equipment used to measure voltage, current, and resistance in an electronic circuit.
Dual In-Line Package (DIP)
A very common IC package with two parallel rows of pins intended to be inserted into a socket of through holes drilled in a printed circuit board.
Engineering Notation
A floating point system in which numbers are expressed as products consisting of a number greater than one multiplied by an appropriate power of ten that is some multiple of three.
Fuse
A protective device in the current path that melts or breaks when current exceeds a predetermined maximum value.
Kirchhoff’s Current Law (KCL)
The algebraic sum of all currents into and out of any branch point in a circuit must equal zero.
Kirchhoff’s Voltage Law (KVL)
The algebraic sum of all voltages around any closed path must equal zero.
Large Scale Integration (LSI)
An IC that contains circuitry equivalent to 100 gates or more.
LED
Light-emitting diode. An electronic device that conducts current in one direction only and illuminates when it is conducting.
Logic Gate
An electronic circuit that performs a Boolean algebraic function.
Logic HIGH
The higher of two voltages in a digital system with two logic levels.
Logic LOW
The lower of two voltages in a digital system with two logic levels.
Medium Scale Integration (MSI)
An IC that contains circuitry equivalent to more than 11 and less than 100 gates.
NOT Gate
Also called an INVERTER gate or an inverting buffer. A logic gate that changes its input logic level to the opposite state.
Ohm
Unit of resistance. Value of one ohm allow current of one ampere with potential difference of one volt.
Ohm’s Law
In electric circuits, I=V/R.
OR Gate
Digital circuit that implements the OR operation. The output of this circuit is HIGH (logic level 1) if any or all of its inputs are HIGH.
Parallel Circuit
One that has two or more branches for separate current from one voltage source.
Plastic Leaded Chip Carrier (PLCC)
A square IC package with leads on all four sides designed for surface mounting on a circuit board.
Printed Circuit Board
Insulating board containing conductive tracks for circuit connections.
Resistance
Opposition to current. Unit is the ohm.
Resistor Color Code
Coding system of colored stripes on a resistor to indicate the resistor's value and tolerance.
Scientific Notation
Numbers entered as a number from one to ten multiplied by a power of ten.
Schottky TTL
TTL subfamily that uses the basic TTL standard circuit except that it uses a Schottky barrier code (SBD) connected between the base and the collector of each transistor for faster switching.
Series Circuit
One that has only one path current.
Seven-Segment Display
An array of seven independently controlled light-emitting diodes (LED) or liquid crystal display (LCD) elements, shaped like a figure-8, which can be used to display decimal digits and other characters by turning on the appropriate elements.
Sequential Logic
Digital circuitry in which the output state of the circuit depends not only on the states of the inputs, but also on the sequence in which they reached their present states.
Simulation
Testing design function by specifying a set of inputs and observing the resultant outputs. Simulation is generally shown as a series of input and output waveforms.
SI Notation
Abbreviation of System International, a system of practical units based on the meter, kilogram, second, ampere, Kelvin, mole, and candela.
Small Outline IC (SOIC)
An IC package similar to a DIP, but smaller, which is designed for automatic placement and soldering on the surface of a circuit board.
Small-Scale Integration (SSI)
An integrated circuit having 12 or fewer gates in one package.
Solder
Metallic alloy of tin and lead that is used to join two metal surfaces.
Solder Bridge
The unwanted formation of a conductive path of solder between conductors.
Soldering
Process of joining two metallic surfaces to make an electrical contact by melting solder (usually tin and lead) across them.
Soldering Iron
Tool with an internal heating element used to heat surfaces being soldered to the point where the solder becomes molten.
Tinning
The process of applying a thin coat of solder to materials prior to their being soldered; for example, application of a light coat of solder to the filaments of a conductor to hold the filaments in place prior to soldering the conductor.
Toggle
To switch from one effect, feature, or state to another.
Transistor
Term derived from "transfer resistor." Semiconductor device that can be used as an amplifier or as an electronic switch.
Transistor-Transistor (TTL)
A family of digital logic devices whose basic element is the bipolar junction transistor.
Truth Table
A list of all possible input values to a digital circuit, listed in ascending binary order, and the output response for each input combination.
A way of representing some physical quantity, such as temperature or velocity, by a proportional continuous voltage or current. An analog voltage or current can have any value within a defined range.
AND Gate
Digital circuit that implements the AND operation. The output of this circuit is HIGH only if all of its inputs are HIGH.
Breadboard
A circuit board for wiring temporary circuits, usually used for prototypes or laboratory work.
Capacitor
An electrical device used to store electrical charge.
Clock
Digital signal in the form of a rectangular pulse train or a square wave.
Combinational Logic
Digital circuitry in which an output is derived from the combination of inputs, independent of the order in which they are applied.
Conventional Current
The direction of current flow associated with positive charge in motion. The current flow direction is from a positive to negative potential, which is in the opposite direction of electron flow.
Current
A movement of electrical charges around a closed path or circuit.
Cycle
A series of events that are regularly repeated in the same order.
Datasheet
A printed specification giving details of the pin configuration, electrical properties, and mechanical profile of an electronic device.
Digital
A way of representing a physical quantity by a series of binary numbers. A digital representation can have only specific discrete values.
Digital Waveform
A series of logic 1s and 0s plotted as a function of time.
Digital Multi-Meter(DMM)
A piece of test equipment used to measure voltage, current, and resistance in an electronic circuit.
Dual In-Line Package (DIP)
A very common IC package with two parallel rows of pins intended to be inserted into a socket of through holes drilled in a printed circuit board.
Engineering Notation
A floating point system in which numbers are expressed as products consisting of a number greater than one multiplied by an appropriate power of ten that is some multiple of three.
Fuse
A protective device in the current path that melts or breaks when current exceeds a predetermined maximum value.
Kirchhoff’s Current Law (KCL)
The algebraic sum of all currents into and out of any branch point in a circuit must equal zero.
Kirchhoff’s Voltage Law (KVL)
The algebraic sum of all voltages around any closed path must equal zero.
Large Scale Integration (LSI)
An IC that contains circuitry equivalent to 100 gates or more.
LED
Light-emitting diode. An electronic device that conducts current in one direction only and illuminates when it is conducting.
Logic Gate
An electronic circuit that performs a Boolean algebraic function.
Logic HIGH
The higher of two voltages in a digital system with two logic levels.
Logic LOW
The lower of two voltages in a digital system with two logic levels.
Medium Scale Integration (MSI)
An IC that contains circuitry equivalent to more than 11 and less than 100 gates.
NOT Gate
Also called an INVERTER gate or an inverting buffer. A logic gate that changes its input logic level to the opposite state.
Ohm
Unit of resistance. Value of one ohm allow current of one ampere with potential difference of one volt.
Ohm’s Law
In electric circuits, I=V/R.
OR Gate
Digital circuit that implements the OR operation. The output of this circuit is HIGH (logic level 1) if any or all of its inputs are HIGH.
Parallel Circuit
One that has two or more branches for separate current from one voltage source.
Plastic Leaded Chip Carrier (PLCC)
A square IC package with leads on all four sides designed for surface mounting on a circuit board.
Printed Circuit Board
Insulating board containing conductive tracks for circuit connections.
Resistance
Opposition to current. Unit is the ohm.
Resistor Color Code
Coding system of colored stripes on a resistor to indicate the resistor's value and tolerance.
Scientific Notation
Numbers entered as a number from one to ten multiplied by a power of ten.
Schottky TTL
TTL subfamily that uses the basic TTL standard circuit except that it uses a Schottky barrier code (SBD) connected between the base and the collector of each transistor for faster switching.
Series Circuit
One that has only one path current.
Seven-Segment Display
An array of seven independently controlled light-emitting diodes (LED) or liquid crystal display (LCD) elements, shaped like a figure-8, which can be used to display decimal digits and other characters by turning on the appropriate elements.
Sequential Logic
Digital circuitry in which the output state of the circuit depends not only on the states of the inputs, but also on the sequence in which they reached their present states.
Simulation
Testing design function by specifying a set of inputs and observing the resultant outputs. Simulation is generally shown as a series of input and output waveforms.
SI Notation
Abbreviation of System International, a system of practical units based on the meter, kilogram, second, ampere, Kelvin, mole, and candela.
Small Outline IC (SOIC)
An IC package similar to a DIP, but smaller, which is designed for automatic placement and soldering on the surface of a circuit board.
Small-Scale Integration (SSI)
An integrated circuit having 12 or fewer gates in one package.
Solder
Metallic alloy of tin and lead that is used to join two metal surfaces.
Solder Bridge
The unwanted formation of a conductive path of solder between conductors.
Soldering
Process of joining two metallic surfaces to make an electrical contact by melting solder (usually tin and lead) across them.
Soldering Iron
Tool with an internal heating element used to heat surfaces being soldered to the point where the solder becomes molten.
Tinning
The process of applying a thin coat of solder to materials prior to their being soldered; for example, application of a light coat of solder to the filaments of a conductor to hold the filaments in place prior to soldering the conductor.
Toggle
To switch from one effect, feature, or state to another.
Transistor
Term derived from "transfer resistor." Semiconductor device that can be used as an amplifier or as an electronic switch.
Transistor-Transistor (TTL)
A family of digital logic devices whose basic element is the bipolar junction transistor.
Truth Table
A list of all possible input values to a digital circuit, listed in ascending binary order, and the output response for each input combination.
Lesson 1.2
Amplitude
The instantaneous voltage of a waveform. Often used to mean maximum amplitude, or peak voltage, or a pulse.
Boolean Expression
An algebraic expression made up of Boolean variables and operators, such as AND (-), OR (+), or NOT (-). Also referred to as Boolean function or a logic function.
Clocked D Flip-Flop
Type of flip-flop in which the D (data) input is the synchronous input.
Digital Waveform
A series of logic 1s and 0s plotted as a function of time.
Dual In-Line Package (DIP)
One style of integrated circuit package which has two rows of lead.
Duty Cycle (DC)
Fraction of the total period that a digital waveform is in the HIGH state. DC = th/T (often expressed as a percentage: %DC = th/Tx100%).
Falling Edge
The part of a pulse where the logic level is in transition from a HIGH to a LOW.
Flip-Flop
A sequential circuit based on a latch whose output changes when its CLOCK input receives a pulse.
Frequency
The number of cycles per unit time of a periodic waveform.
Hertz (Hz)
Unit of frequency. One hertz equals one cycle per second.
Integrated Circuit (IC)
An electronic circuit having many components, such as transistors, diodes, resistors, and capacitors, in a single package.
Inverter
Also called a NOT gate or an inverting buffer. A logic gate that changes its input logic level to the opposite state.
Logic Diagram
A diagram, similar to a schematic, showing the connection of logic gates.
Oscilloscope
A piece of test equipment used to view and measure a variety of different waveforms.
Period
The amount of time required for one complete cycle of a periodic event or waveform.
Propagation Delays (tPLH/tPHL)
Delay from the time a signal is applied to the time when the output makes its change.
Schematic Entry
A technique of entering CPLD design information by using a CAD (computer aided design) tool to draw a logic circuit as a schematic. The schematic can then be interpreted by design software to generate programming information for the CPLD.
Sine Wave
One in which amplitude varies in proportion to the sine function of an angle.
Square Wave
An almost instantaneous rise and decay of voltage or current in a periodic pattern with time and with a constant peak value.
555 Timer
TTL-compatible IC that can be wired to operate in several different modes, such as a one-shot and an astable multivibrator.
The instantaneous voltage of a waveform. Often used to mean maximum amplitude, or peak voltage, or a pulse.
Boolean Expression
An algebraic expression made up of Boolean variables and operators, such as AND (-), OR (+), or NOT (-). Also referred to as Boolean function or a logic function.
Clocked D Flip-Flop
Type of flip-flop in which the D (data) input is the synchronous input.
Digital Waveform
A series of logic 1s and 0s plotted as a function of time.
Dual In-Line Package (DIP)
One style of integrated circuit package which has two rows of lead.
Duty Cycle (DC)
Fraction of the total period that a digital waveform is in the HIGH state. DC = th/T (often expressed as a percentage: %DC = th/Tx100%).
Falling Edge
The part of a pulse where the logic level is in transition from a HIGH to a LOW.
Flip-Flop
A sequential circuit based on a latch whose output changes when its CLOCK input receives a pulse.
Frequency
The number of cycles per unit time of a periodic waveform.
Hertz (Hz)
Unit of frequency. One hertz equals one cycle per second.
Integrated Circuit (IC)
An electronic circuit having many components, such as transistors, diodes, resistors, and capacitors, in a single package.
Inverter
Also called a NOT gate or an inverting buffer. A logic gate that changes its input logic level to the opposite state.
Logic Diagram
A diagram, similar to a schematic, showing the connection of logic gates.
Oscilloscope
A piece of test equipment used to view and measure a variety of different waveforms.
Period
The amount of time required for one complete cycle of a periodic event or waveform.
Propagation Delays (tPLH/tPHL)
Delay from the time a signal is applied to the time when the output makes its change.
Schematic Entry
A technique of entering CPLD design information by using a CAD (computer aided design) tool to draw a logic circuit as a schematic. The schematic can then be interpreted by design software to generate programming information for the CPLD.
Sine Wave
One in which amplitude varies in proportion to the sine function of an angle.
Square Wave
An almost instantaneous rise and decay of voltage or current in a periodic pattern with time and with a constant peak value.
555 Timer
TTL-compatible IC that can be wired to operate in several different modes, such as a one-shot and an astable multivibrator.
Lesson 2.3
Common Anode Display
A seven-segment LED display where the anodes of all the LEDs are connected to the circuit supply voltage. Each segment is illuminated by a logic LOW at its cathode.
Common Cathode Display
A seven-segment display in which the cathodes of all the LEDs are connected together and grounded. A logic HIGH illuminates a segment when applied to its anode.
Datasheet
A printed specification giving details of the pin configuration, electrical properties, and mechanical profile of an electronic device.
De-multiplexer
A circuit that uses a binary decoder to direct a digital signal from a single source to one of several destinations.
Design Specifications
A detailed description, especially one providing information needed to make, build, or produce something.
Encoder
A digital circuit that produces an output code depending on which of its inputs is activated.
Exclusive-NOR (XNOR) Circuit
Two-input logic circuit that produces a high output only when the inputs are equal.
Exclusive-OR (XOR) Circuit
Two-input logic circuit that produces a high output only when the inputs are different.
Full Adder
Logic circuit with three inputs and two outputs. The inputs are a carry bit (CIN) from a previous stage, a bit from the augend, and a bit from the addend, respectively. The outputs are the sum bit and the carry-out bit (COUT) produced by the addition of the bit from the addend with the bit from the augend and CIN.
Half Adder
Logic circuit with two inputs and two outputs. The inputs are a bit from the augend and a bit from the addend. The outputs are the sum bit produced by the addition of the bit from the addend with the bit from the augend and the resulting carry (COUT) bit, which will be added to the next stage.
Hexadecimal Number System
Base-16 number system. Hexadecimal numbers are written with sixteen digits, 0-9 and A-F, with power-of-16 positional multipliers.
Multiplexer
A circuit that directs one of several digital signals to a single output, depending on the states of several select inputs.
Octal Number System
A number system that has a base of 8; digits from 0 to 7 are used to express an octal number.
Seven-Segment Display
An array of seven independently controlled light-emitting diodes (LED) or liquid crystal display (LCD) elements, shaped like a figure-8, which can be used to display decimal digits and other characters by turning on the appropriate elements.
Signed Binary Number
A binary number of fixed length whose sign is represented by one bit, usually the most significant bit, and whose magnitude is represented by the remaining bits.
Sign Bit
A binary bit that is added to the leftmost position of a binary number to indicate whether that number represents a positive or a negative quantity.
1’s Complement
A form of signed binary notation in which negative numbers are created by complementing all bits of a number, including the sign bit.
2’s Complement
A form of signed binary notation in which negative numbers are created by adding 1 to the 1’s complement form of the number.
A seven-segment LED display where the anodes of all the LEDs are connected to the circuit supply voltage. Each segment is illuminated by a logic LOW at its cathode.
Common Cathode Display
A seven-segment display in which the cathodes of all the LEDs are connected together and grounded. A logic HIGH illuminates a segment when applied to its anode.
Datasheet
A printed specification giving details of the pin configuration, electrical properties, and mechanical profile of an electronic device.
De-multiplexer
A circuit that uses a binary decoder to direct a digital signal from a single source to one of several destinations.
Design Specifications
A detailed description, especially one providing information needed to make, build, or produce something.
Encoder
A digital circuit that produces an output code depending on which of its inputs is activated.
Exclusive-NOR (XNOR) Circuit
Two-input logic circuit that produces a high output only when the inputs are equal.
Exclusive-OR (XOR) Circuit
Two-input logic circuit that produces a high output only when the inputs are different.
Full Adder
Logic circuit with three inputs and two outputs. The inputs are a carry bit (CIN) from a previous stage, a bit from the augend, and a bit from the addend, respectively. The outputs are the sum bit and the carry-out bit (COUT) produced by the addition of the bit from the addend with the bit from the augend and CIN.
Half Adder
Logic circuit with two inputs and two outputs. The inputs are a bit from the augend and a bit from the addend. The outputs are the sum bit produced by the addition of the bit from the addend with the bit from the augend and the resulting carry (COUT) bit, which will be added to the next stage.
Hexadecimal Number System
Base-16 number system. Hexadecimal numbers are written with sixteen digits, 0-9 and A-F, with power-of-16 positional multipliers.
Multiplexer
A circuit that directs one of several digital signals to a single output, depending on the states of several select inputs.
Octal Number System
A number system that has a base of 8; digits from 0 to 7 are used to express an octal number.
Seven-Segment Display
An array of seven independently controlled light-emitting diodes (LED) or liquid crystal display (LCD) elements, shaped like a figure-8, which can be used to display decimal digits and other characters by turning on the appropriate elements.
Signed Binary Number
A binary number of fixed length whose sign is represented by one bit, usually the most significant bit, and whose magnitude is represented by the remaining bits.
Sign Bit
A binary bit that is added to the leftmost position of a binary number to indicate whether that number represents a positive or a negative quantity.
1’s Complement
A form of signed binary notation in which negative numbers are created by complementing all bits of a number, including the sign bit.
2’s Complement
A form of signed binary notation in which negative numbers are created by adding 1 to the 1’s complement form of the number.
Lesson 2.4
Complex PLD (CPLD)
A digital device consisting of several programmable sections with internal interconnections between the sections.
Compiler
The process used by CPLD design software to interpret design information (such as a schematic or text file) and create required programming information for a CPLD.
Design Entry
The process of using software tools to describe the design requirements of a PLD. Design entry can be done by entering a schematic or a text file that describes the required digital function.
Field Programmable Gate Array (FPGA)
Class of PLDs that contain an array of more complex logic cells that can be very flexibly interconnected to implement high-level logic circuits.
Fitting
Assigning internal PLD circuitry, and input and output pins, to a PLD design.
Integrated Circuit (IC)
An electronic circuit having many components, such as transistors, diodes, resistors, and capacitors, in a single package.
JTAG Port
A four-wire interface specified by the Joint Test Action Group (JTAG) used for loading test data or programming data into a PLD installed in a circuit.
JEDEC
Joint Electron Device Engineering Council.
JEDEC File
An industry standard form of text file indicating which fuses are blown and which are intact in a programmable logic device.
JTAG
Joint Test Action Group. A standards body that developed the format for testing and programming devices while they are installed in a system.
Programmable Logic Device (PLD)
Digital integrated circuit that can be programmed by the user to implement any digital logic function.
Programming
Transferring design information from the computer running PLD design software to the actual PLD chip.
Schematic Entry
A technique of entering CPLD design information by using a CAD (computer aided design) tool to draw a logic circuit as a schematic. The schematic can then be interpreted by design software to generate programming information for the CPLD.
Simple PLD (SPLD)
A PLD with a few hundred logic gates and possibly a few programmable macro cells available.
Target Device
The specific PLD for which a digital design is intended.
TCK
Test Clock. The JTAG signal that drives the JTAG downloading process from one state to the next.
TDI
Test Data In. In a JTAG port, the serial input data to a device.
TDO
Test Data Out. In a JTAG port, the serial output data from a device.
TMS
Test Mode Select. The JTAG signal that controls the downloading of test or programming data.
A digital device consisting of several programmable sections with internal interconnections between the sections.
Compiler
The process used by CPLD design software to interpret design information (such as a schematic or text file) and create required programming information for a CPLD.
Design Entry
The process of using software tools to describe the design requirements of a PLD. Design entry can be done by entering a schematic or a text file that describes the required digital function.
Field Programmable Gate Array (FPGA)
Class of PLDs that contain an array of more complex logic cells that can be very flexibly interconnected to implement high-level logic circuits.
Fitting
Assigning internal PLD circuitry, and input and output pins, to a PLD design.
Integrated Circuit (IC)
An electronic circuit having many components, such as transistors, diodes, resistors, and capacitors, in a single package.
JTAG Port
A four-wire interface specified by the Joint Test Action Group (JTAG) used for loading test data or programming data into a PLD installed in a circuit.
JEDEC
Joint Electron Device Engineering Council.
JEDEC File
An industry standard form of text file indicating which fuses are blown and which are intact in a programmable logic device.
JTAG
Joint Test Action Group. A standards body that developed the format for testing and programming devices while they are installed in a system.
Programmable Logic Device (PLD)
Digital integrated circuit that can be programmed by the user to implement any digital logic function.
Programming
Transferring design information from the computer running PLD design software to the actual PLD chip.
Schematic Entry
A technique of entering CPLD design information by using a CAD (computer aided design) tool to draw a logic circuit as a schematic. The schematic can then be interpreted by design software to generate programming information for the CPLD.
Simple PLD (SPLD)
A PLD with a few hundred logic gates and possibly a few programmable macro cells available.
Target Device
The specific PLD for which a digital design is intended.
TCK
Test Clock. The JTAG signal that drives the JTAG downloading process from one state to the next.
TDI
Test Data In. In a JTAG port, the serial input data to a device.
TDO
Test Data Out. In a JTAG port, the serial output data from a device.
TMS
Test Mode Select. The JTAG signal that controls the downloading of test or programming data.
lesson 3.1
Asynchronous Counter
Type of counter in which each flip-flop output serves as the clock input signal for the next flip-flop in the chain.
Asynchronous Inputs
Flip-flop inputs that can affect the operation of the flip-flop independent of the synchronous and clock inputs.
Clock
Digital signal in the form of a rectangular pulse train or a square wave.
Clocked D Flip-Flop
Type of flip-flop in which the D (data) input is the synchronous input.
Clocked J-K Flip-Flop
Type of flip-flop in which inputs J and K are the synchronous inputs.
D Latch
Circuit that contains a NAND gate latch and two steering NAND gates.
Duty Cycle (DC)
Fraction of the total period that a digital waveform is in the HIGH state. DC = th/T (often expressed as a percentage: %DC = th/Tx100%).
Edge-Sensitive
Manner in which a flip-flop is activated by a signal transition. A flip-flop may be either a positive- or a negative-edge-triggered flip-flop.
Falling Edge
The part of a pulse where the logic level is in transition from a HIGH to a LOW.
Flip-Flop
A sequential circuit based on a latch whose output changes when its CLOCK input receives a pulse.
Frequency
The number of cycles per unit time of a periodic waveform.
Level-Sensitive
Enabled by a logic HIGH or LOW level.
Period
The amount of time required for one complete cycle of a periodic event or waveform.
PRESET
Asynchronous input used to set Q=1 immediately.
Propagation Delays (tPLH/tPHL)
Delay from the time a signal is applied to the time when the output makes its change.
RESET / CLEAR
Asynchronous input used to set Q=0 immediately.
Rising Edge
The part of a pulse where the logic level is in transition from a LOW to a HIGH.
Sequential Logic
Digital circuitry in which the output state of the circuit depends not only on the states of the inputs, but also on the sequence in which they reached their present states.
Shift Register
Digital circuit that accepts binary data from some input source and then shifts these data through a chain of flip-flops one bit at a time.
State Machines
A sequential circuit that advances through several defined states.
Synchronous Counter
Counter in which all of the flip-flops are clocked simultaneously.
Trigger
Input signal to a flip-flop or one-shot that causes the output to change states depending on the conditions of the control signals.
Type of counter in which each flip-flop output serves as the clock input signal for the next flip-flop in the chain.
Asynchronous Inputs
Flip-flop inputs that can affect the operation of the flip-flop independent of the synchronous and clock inputs.
Clock
Digital signal in the form of a rectangular pulse train or a square wave.
Clocked D Flip-Flop
Type of flip-flop in which the D (data) input is the synchronous input.
Clocked J-K Flip-Flop
Type of flip-flop in which inputs J and K are the synchronous inputs.
D Latch
Circuit that contains a NAND gate latch and two steering NAND gates.
Duty Cycle (DC)
Fraction of the total period that a digital waveform is in the HIGH state. DC = th/T (often expressed as a percentage: %DC = th/Tx100%).
Edge-Sensitive
Manner in which a flip-flop is activated by a signal transition. A flip-flop may be either a positive- or a negative-edge-triggered flip-flop.
Falling Edge
The part of a pulse where the logic level is in transition from a HIGH to a LOW.
Flip-Flop
A sequential circuit based on a latch whose output changes when its CLOCK input receives a pulse.
Frequency
The number of cycles per unit time of a periodic waveform.
Level-Sensitive
Enabled by a logic HIGH or LOW level.
Period
The amount of time required for one complete cycle of a periodic event or waveform.
PRESET
Asynchronous input used to set Q=1 immediately.
Propagation Delays (tPLH/tPHL)
Delay from the time a signal is applied to the time when the output makes its change.
RESET / CLEAR
Asynchronous input used to set Q=0 immediately.
Rising Edge
The part of a pulse where the logic level is in transition from a LOW to a HIGH.
Sequential Logic
Digital circuitry in which the output state of the circuit depends not only on the states of the inputs, but also on the sequence in which they reached their present states.
Shift Register
Digital circuit that accepts binary data from some input source and then shifts these data through a chain of flip-flops one bit at a time.
State Machines
A sequential circuit that advances through several defined states.
Synchronous Counter
Counter in which all of the flip-flops are clocked simultaneously.
Trigger
Input signal to a flip-flop or one-shot that causes the output to change states depending on the conditions of the control signals.
Lesson 3.2
Asynchronous Counter
Type of counter in which each flip-flop output serves as the clock input signal for the next flip-flop in the chain.
Binary Counter
Group of flip-flops connected in a special arrangement in which the states of the flip-flops represent the binary number equivalent to the number of pulses that have occurred at the input of the counter.
Decade Counter
Any counter capable of going through 10 different logic states.
Down Counter
Counter that counts from a maximum count downward to 0.
Modulus
The number of states through which a counter sequences before repeating.
Modulus N Counter
(mod-n counter)
A counter with a modulus of N.
Synchronous Counter
Counter in which all of the flip-flops are clocked simultaneously.
Up Counter
Counter that counts upward from 0 to a maximum count.
Up/Down Counter
Counter that can count up or down depending on how its inputs are activated.
Type of counter in which each flip-flop output serves as the clock input signal for the next flip-flop in the chain.
Binary Counter
Group of flip-flops connected in a special arrangement in which the states of the flip-flops represent the binary number equivalent to the number of pulses that have occurred at the input of the counter.
Decade Counter
Any counter capable of going through 10 different logic states.
Down Counter
Counter that counts from a maximum count downward to 0.
Modulus
The number of states through which a counter sequences before repeating.
Modulus N Counter
(mod-n counter)
A counter with a modulus of N.
Synchronous Counter
Counter in which all of the flip-flops are clocked simultaneously.
Up Counter
Counter that counts upward from 0 to a maximum count.
Up/Down Counter
Counter that can count up or down depending on how its inputs are activated.
Lesson 4.1
Bubble
A circle in a state diagram containing the state name and values of the state variables.
Conditional Transition
A transition between states of a state machine that occurs only under specific conditions of one or more control inputs.
Control Input
A state machine input that directs the operation of the machine from state to state.
Mealy Machine
A state machine whose output is determined by both the sequential logic and the combinational logic of the machine.
Moore Machine
A state machine whose output is determined only by the sequential logic of the machine.
State Machines
A synchronous sequential circuit, consisting of a sequential logic section and a combinational logic section, whose outputs and internal flip-flops progress through a predictable sequence of states in responds to a clock and other input signals.
State Table
A table whose entries represent the sequence of individual FF states (i.e., 0 or 1) for a sequential binary circuit.
State Transition Diagram
A graphic representation of the operation of a sequential binary circuit, showing the sequence of individual FF states and conditions needed for transitions from one state to the next.
State Variables
The variables held in the flip-flops of a state machine that determine its present state.
A circle in a state diagram containing the state name and values of the state variables.
Conditional Transition
A transition between states of a state machine that occurs only under specific conditions of one or more control inputs.
Control Input
A state machine input that directs the operation of the machine from state to state.
Mealy Machine
A state machine whose output is determined by both the sequential logic and the combinational logic of the machine.
Moore Machine
A state machine whose output is determined only by the sequential logic of the machine.
State Machines
A synchronous sequential circuit, consisting of a sequential logic section and a combinational logic section, whose outputs and internal flip-flops progress through a predictable sequence of states in responds to a clock and other input signals.
State Table
A table whose entries represent the sequence of individual FF states (i.e., 0 or 1) for a sequential binary circuit.
State Transition Diagram
A graphic representation of the operation of a sequential binary circuit, showing the sequence of individual FF states and conditions needed for transitions from one state to the next.
State Variables
The variables held in the flip-flops of a state machine that determine its present state.