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Techno : Technical lexicon of the Numerical Micro-electronics

This fourth technology is in fact a technical lexicon defining the terms of everyday usage in the publications of numerical micro-electronics. A particular place is granted here to the abbreviations and the English expressions used usually in this field.

Only the terms of general natures are pointed out, the other not quoted terms were defined in the courses of the theories and practical digital preceding.

Certain terms rather relate to the microprocessors and their functions and thus exceed slightly the strict framework of numerical electronics. They nevertheless were mentioned to familiarize you as of now with these components which make the object of third most of our talk in its summary heading “Microprocesseurs and Microcomputers”.



ACRONYM: Word consisted the first letters of the words of an expression (for example, COBOL: COmmon Business Oriented Language).

A / D CONVERTER : (Analog / Digital C), to see CONVERTER A / N.


ADRESS : address.

ADDRESS : It is a combination of bits which indicates for a memory the position to which is stored information.

Algebra : Technique of calculation using the setting in equation of the phenomena by means of letter symbols.

Boolean algebra : Logical algebra, to see ALGEBRA AND BOOLEAN.

Algorithm : Process or together of rules or operations which it is necessary to carry out to arrive at a result.

ALU : (Arithmetic Logic Links), Voir ARITHMETIC LOGICAL UNIT.

AM : (Amplitude Modulation), modulation of a carrying sinusoidal wave in which the variation of amplitude is proportional to the instantaneous value of the modulating signal.

AMPLIFIER : Circuit allowing to increase the amplitude of a physical size.

DIFFERENTIAL AMPLIFIER : It is an amplifier with two entries and an exit. The output signal is directly proportional to the difference between the two input signals.

OPERATIONAL AMPLIFIER : It is an amplifier which, employed in adapted assemblies, makes it possible to carry out operations such as summons signals, reversed, integrations…

AMPLIFICATION : A pure number characterizing the relationship between the tension of entry and the output voltage, the current of entry and the output current or the power of entry and the power of exit in an analogical amplifier.

ANALOGICAL : A device is known as analogical when the signal delivered at the exit is proportional at any moment to the variation of the physical size which with given him birth.


AND : See ET.

ANODE : (Of a diode), positive electrode of a diode. When one applies the positive tension of the circuit to him, the diode is traversed by a forward current.

ARQ : (Automatic Request for repetition), automatic request for repetition of a character when in a teleprinter, a signal of error is generated. The error is reserved by the receiving system during the decoding of the signal of character.

ASCII : (To pronounce Askii, American Standard Codes Information off Interchanges), together binary codes allowing to represent 128 typographical characters, adopted by the ASA (American Standard Association).

ASK : (Amplitude Keying Shift), coding of information by modulation of carrying by means of a signal in stair derived from the numerical signal from origin.

ASR : (Automatic Send and Receive), automatic emission reception. The same acronym is used to indicate a terminal read/write drive with punched tape.

ASSEMBLER : Program which translates into computer code a program written in mnemonic language.

ASTABLE : (Multivibrator, rocks), circuit having two possible states of which none is stable so that the circuit oscillates spontaneously. An oscillator is a circuit astable.

ASYNCHRONOUS : Is called asynchronous, a device ordered directly by the numerical signal of entry. In the asynchronous circuits, the signals evolve/move without the assistance of clock pulses.





BASE : (Of a transistor), electrode consisted the zone ranging between the transmitter and the collector, generally control the electrode of the transistor.

BAUD : Measuring unit speed transmission of the data along a line. By the same name, one usually indicates the bit per second, symbol B.

BCD : (Binary Coded Decimal), numbering system in which the current Arab numerals (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) are replaced by the respective binary values and are coded by group of four binary digits : 00002 = 0, 00012 = 1, 00102 = 10, 00112 = 3, 01002 = 4, 01012 = 5, 01102 = 6, 01112 = 7, 10002 = 8 10012 = 9.


BIPOLAR : (Technology, integrated circuit), this term means that this technology uses bipolar transistors, in opposition to the field-effect transistors.

FLIP-FLOP : (Multivibrator, rocks), circuit able to take two stable states. To rock, this circuit requires an external order.

BIT : (BInary Digit), unit of information in binary logic represented conventionally by 0 or 1.

BOOLEAN : Says itself of a system using the logic of Boole.

BORROW : Negative reserve, signal generated by a discounting machine at the time of its passage to 0.

BREADBOARD : Stamp with contacts, plates on which one can carry out experimental loops by simple assembling of the components.

NOISE : Disturbance which can modify the data, during a transmission, for example. It can be of origin sector or due to thermal agitation in materials.

BUBBLE MEMORY : Bubble memory, to see MÉMOIRE A BULLES.

BUFFER : Device or circuit inserted between two other circuits to adapt them one to the other. For the integrated circuits: amplifier reverser or not reverser which increases the fan-out or adapts the levels (case of the connections between TTL and CMOS).

BUFFERED : Bufférisé, to see BUFFERISÉ.

BUFFERISÉ : Indicate that a digital circuit is provided with a BUFFER what increases its fan-out or pyramidal factor. Can also state that a circuit comprises a buffer memory.

BUS : Together of lines on which data forward.

BYTE : Together of bits constituting a word.



CALCULATOR : Indicate a powerful computer or the calculating unit of a computer.

COMPUTER : Machine or electronic instrument used to carry out calculations. Require many manual interventions. Can be of pocket or office.

CALCULATOR : Computer, to see COMPUTER.

CHANNEL : Frequency allocated with an emission or more generally line of transmission. Course de binder between source and drain in a FET.

CANONICAL : (Algebraical expression setting in the canonical form), says itself of an algebraical expression in Boolean algebra when it is appeared as a sum of “mintermes” or the shape of a product of “maxtermes”. (See MINTERME, MAXTERME).

STORAGE CAPACITY : It is the number of units of information (bits) which can be stored in a memory. It can be also expressed in a number of Bytes or words.

CHARACTER : Sign graphic, letter, figure, or another typing sign.

CURRY : Carryforward, to see CARRYFORWARD.

CATHODE : (Of a diode), negative electrode of the diode. When one applies the negative tension of the circuit to him, the diode is traversed by a forward current.

C.C.D. : (Load Coupled Device), device of memory, primarily made up by a system with condensers, integrated in a semiconductor monocrystal. The information which it contains is associated the presence or the absence of loads in the zones of the semiconductor which provide the function of reinforcement.

CELL : (Of memory), it is the basic element of the memory, it contains a bit.

CHANEL : Channel, to see CANAL.

CHANEL CAPACITY : capacity of a channel. It is the maximum quantity of information that one can transmit during a time given through a channel.

QUANTIFY : Each character being used to represent the numbers. For example, figures 1 and 0 into binary. Figures 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F into hexadecimal.

CHIP : Chip. It is a low-size pastille (a few square millimetres), generally out of silicon, on which the circuit is engraved. The chip is coated in a case with hermetically closed plastic or ceramics.


INTEGRATED CIRCUIT : Summary in IC (Integrated Circuit). It is a microcircuit formed with a semiconductor crystal pastille (chip).

CLEAR : Restoring. An active signal applied to entry CLEAR gives to zero the exit of the circuit. It is synonymous with RESET.

CLOCK : Clock, to see SYNCHRONOUS.

CMOS : (Complementary Semi-conductor Oxide Metal), metal oxide semiconductor with complementary symmetry. Generally, they are logical circuits which have like fundamental cell a reverser formed by two FET with channel of the opposite type P and N.

CODE : Group symbols (letters, figures or other characters) organized in a given way to represent information.

BINARY CODE : System of coding where each data is represented by a binary digit.

DECIMAL CODE : Digital code formed by ten digits from 0 to 9.

HAMMING CODE : Code used for the transmission of the data having useful characteristics for the autocorrection of the errors.

HEXADECIMAL CODE : Formed digital code of the sixteen digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.

GRAY CODE : Digital code, composed of four bits per figure, so that when one counts or deducts of 1, only a bit changes.

COLLECTOR : (Of transistor), electrode of power of the transistor, to see FUNDAMENTAL ASSEMBLIES OF THE TRANSISTOR, in Technology 1.

OPEN COLLECTOR : Bipolar integrated circuit without internal resistance of collector. With the circuits of this type, one can connect several exits together. By feeding them through an external resistance connected to “+” (called resistance of “Up Sweater”), one obtains a named switching function “OR cabled”.

COMBINATIVE : (Circuit), circuit in which the level of the exits east constantly function of the level of the entries whatever their preceding levels.

COMPARATOR : Device which compares two signals sent on its entries and can indicate if they are equal or not.



COMPLEMENT A 2K : The complement with 2K of a binary number is the number which, added the first, makes it possible to obtain 2K. For example, the complement with 23 of 1012 is 0112, indeed 1012 + 0112 = 10002 = 810 = 23. By convention, one says simply complement to 2 for complement with 2K.

COMPLEMENT A 2K - 1 : The complement with 2K - 1 is the binary number which, added the first, makes it possible to obtain 2K - 1. For example, the complement with 23 - 1 of 1012 is 0102. Indeed, 1012 + 0102 = 1112 = 710 = 8 - 1 = 23 - 1. Usually, instead of saying “complement to 2K - 1”, one says “complement to 1”.

METER : Device able to record a succession of elementary signals, to make counting and to give the result in numerical form of it.

METER BCD : Decimal scaler in which each figure is coded into binary on four bits.

BINARY COUNTER : Together of rockers put in cascade whose combination of the levels of the exits constitutes the binary number of the impulses applied to the entry.

CLOSED COUNTING CHAIN : Chain closed rockers such as only one of them has its active level of exit. On arrival of the impulses of entry, this level shifts rockers of rockers in a direction or the other until it returned to its initial position.

COMPUTER : Computer (generally electronic), to see ORDINATEUR.

TO CONTROL : Device allowing to control the course of a technical process.

CONVERTER A / D : Analogica / digital converter, to see CONVERTER A / N.

CONVERTER A / N : Circuit making it possible to transform an analogical signal into numerical signal are equivalent.

CONVERTER D / A: Converter digital/analogical, to see CONVERTER N / A.

CONVERTER N / A : Circuit allowing to transform a numerical signal into analogical signal.

CODE TRANSLATOR : Device allowing to transform a signal using a code given into a signal having the same significance but expressed in another code.

COS / MOS: (Complementary Symetry / Semi-conductor Oxide Metal), acronym used by certain manufacturers in the place of CMOS (See CMOS).

CPU : Acronym of Processing Exchange Links (Central processing unit of treatment or calculation), formed together by the arithmetic unit, the logical unit, the registers and associated logic.

CRT : (Ray Cathode Tubes), cathode-ray tube (TRC).



D / A CONVERTER : (Digital / Analog C), to see CONVERTISSEUR D / A.

DEBUG : Examination and test of a program to find possible defects.

DECAY-TIME : Time of descent or decrease. Time put by the tension to pass from the high level on the bottom grade. It is measured between the decrease of the tension from 90 % to 10 %.

DECIMAL CODE: Decimal code, to see CODE DÉCIMAL.

TO DECODE : Decoder, to see DECODER.

DECODER : Circuit at several exits, active according to the combination of the signals applied to the entries. For example, a decoder 4 towards 16 has 4 entries and 16 exits. The binary number with four bits applied to the entries defines which is the exit which is active. Thus, for example, combination 0000 activates exit 0 ; to combination 0011 exit 3 and so on corresponds.

DÉCRÉMENTER : To deduct.

DEMULTIPLEXER : Digital circuit including/understanding only one entry and several exits. One or more entries of order allowing to switch the input signal on one of the selected exits. It carries out the opposite operation of that carried out by a multiplexer.



DIL : See DIP.

DIODE : Device which allows the passage of the current only in one direction.

DIP : (Dual In line Package), case of integrated circuit into double line of pins.

SAYABLE : To invalidate, inhibit.

DISPLAY : (Bill-poster), device allowing to visualize information in graphic form (cathode ray tube, bill-poster with seven segments).

DRAIN : (Of FET), electrode of power of a field-effect transistor, the other end of the channel being called SOURCE and the control electrode ROASTS or SPOILS.

DRIVER : (Pilot), electronic circuit which provides the signal to another circuit by presenting it suitably amplified. Become English term of everyday usage in the technicians speaking about other languages ; in French, pilot or driver means.



EAROM : (Liable to deterioration Electrically Read Only Memory), memory with reading alone in which one can however modify recorded information; but for this last operation, the access time is very long. The EAROM is a nonvolatile memory.

ECL: (Emitter Coupled Logic), logic with coupling of transmitter. Family of bipolar integrated circuits into very short response time (speed ten times higher than that of the TTL).

EDITOR : Program of assistance to the programming generally contained in a ROM.

EDITOR : Editor, to see EDITOR.

EEPROM : (Programmable Electrically Erasable Read Only Memory), memory with authorized, only erasable reading electrically. It is a particular type of EPROM.


ELECTRODE : Driver connecting a discrete active component such as diode, vacuum tube or transistor with a source of food. The electrodes of a diode are the anode (positive electrode), cathode (negative electrode) ; for a transistor, one distinguishes the base, the collector, the transmitter ; for a field-effect transistor : the drain, the source and the grid. One also speaks about the electrodes of an arc welding set or of a voltmeter.

TRANSMITTER : (Of transistor), electrode of a bipolar transistor, to see assembly of the transistor out of common transmitter in Technology 1.

ENABLE : (In French «valider»), one indicates by this term the entry of order of various logical circuits, this entry allowing the operation of this circuit.

FAN-IN : It is the number of doors standards which can attack a circuit. In TTL, a fan-in of 1 corresponds to a current of 1,6 mA, in the entry of the circuit considered ; a fan-in of 2 will represent a current of 3,2 mA. The circuits CMOS do not consume which can of current, also their fan-in is not significant.

EPROM : (Programmable Erasable Read Only Memory), erasable storage with possible reading only. It is about a PROM (see PROM) which, in addition to the fact of being programmable, can be erased and in which one can thus write again.

AND : Switching function, still called logical product, such as f = a AND b is written f = a . b ; integrated circuit or carries fulfilling this function.

LOGICAL STATE : Level or combination of logical levels present on the terminals of entries, exits and on the connections intern of a logical circuit.

EX - OR : Exclusive - OR, to see EXCLUSIVE - OR.




LOGICAL FAMILY : Series of numerical components (doors, rockers, meters…) realized with same technology. All the components of a logical family are compatible between them. The most known families are the TTL (Transistor Logic Transistor), the ECL (Emittor Coupled Logic) and the CMOS (Complementary Metal Oxide Semi-conductor).

FAN-IN : Fan-in, to see FAN-IN.

FAN-OUT : Fan-out, to see FAN-OUT.

FET : (Field Effect Transistor), Field-effect transistor. It is about a semiconductor active component, like the bipolar transistor. With the difference in this last which is ordered while running, the FET is ordered in tension.

FIFO: (First Input, First Ouput), memory known as “pipe” in which the first introduced data are available the first.

FIRMWARE : Type of software recorded in a ROM, (see SOFTWARE and ROM). In general, they are instructions and built-in immutable programs as a hardware in the machine or the system (see HARDWARE).

FLIP-FLOP : (Rocker), it is a bistable circuit, i.e. whose exits can take two stable states 1 or 0. It generally has two exits Q and Q_barre.gif. When the level of the tension of an exit is high, the other is on the bottom grade. The state of the exit at a given moment depends on the changes of level of tension on the entries having preceded this moment. One can thus say that it is a sequential circuit. This circuit makes it possible to memorize a bit. Several flip-failures put in cascade can constitute memories or registers.

FLIP-FLOP D : (Rocker D), it is a synchronous rocker with an input called D. The level of the exit of the rocker is same as that present at the entry D at the time when the last clock pulse arrives. If, for example, the entry is on a high level, the exit Q, after the following clock pulse will be, at the high level.

FLIP-FLOP J-K : It is a synchronous rocker with two entries J and K. When J is at the high level and K on the level L, a clock pulse makes pass the exit on the level H. With J on the bottom grade and K on the level H, the exit passes on the level L at the time of a clock pulse. When J and K are both H, the level of exit changes whatever are state: if this one is L, it becomes H and vice versa. With J and K both on the level L, the rocker remains with the state where it is.

FLIP-FLOP RS : Rock RS with two entries generally of asynchronous type, one RESET, the other SET allowing to position the rocker with 0 or 1.

SYNCHRONOUS FLIP-FLOP : Rock which has an entry of clock. The change of the level of the entries does not involve the change of the level of the exits. A clock pulse is necessary for that. Often, there are two other entries : PRESET (or SET) and CLEAR (or RESET). They are used respectively to force the rocker with the state SET and the state RESET independently of the clock signal.

FLIP-FLOP T : (Toggle), in fact rockers change state with each active face of clock. At exit, one obtains a signal whose frequency is the rise of that of the clock signal.

FM : (Frequency Modulation), type of modulation which varies the frequency of carrying according to the modulating signal.

SWITCHING FUNCTION : Elementary function realized by means of a door or operator logical AND, OR, NAND, NOR. Relation which binds Boolean variables of entry to a variable of exit.


CANONICAL FORM : Algebraical expression in logic of Boole put in the form of nap of mintermes or product of maxtermes.

FULL ADDER : Complete summoner, to see COMPLETE SUMMONER.

FUSE LINK : Fusible connection. Connection which is cut or remained intact so as to register in memory a bit (0 or 1).



PROFIT : Value characterizing amplification in an analogical amplifier. Express yourself in decibels. The profit in tension, for example, will be 20 times the logarithm of the report/ratio of the output voltage on the tension of entry.

SPOIL : Roast or carries. Carry logical or control electrode of the field-effect transistors. One also speaks about “spoils” or doors AND, OR, NAND, NOR, OR Exclusive… “Spoils” of a field-effect transistor is its control electrode consisted an insulated metal plate.

GENERATOR OF CHARACTER : Logical unit which transforms the alphanumeric codes into electric signals necessary to generally visualize information in the form of characters on a cathode ray tube.

GLITCH : Parasitic impulse of short duration which can be due to phenomena of commutation, times of transit or disturbances electromagnetic and which causes errors or breakdowns.

GND : Abbreviation of ground, i.e. ground or mass, to see GROUND.

GRAY CODES : Gray code, to see GRAY CODE.


GROUND : Ground or mass. On the diagrams or the electricals appliance, the terminal connected to the ground or the mass indicates.



HALF ADDER : Half-summoner or half-adder.


HARDWARE : One indicates by hardware the whole of the systems or material constituting an automatic or data-processing whole except for the programs which it contains, those being regarded as immaterial.

HEXADECIMAL : (System), numbering system based on the use of 16 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.


HYSTERESIS : Delay of the variations of magnetization compared to the magnetizing field, characteristic of the ferromagnetic bodies. In the case of electronic devices, delay of the evolution of the output signal compared to the input signal which makes that the first depends on the current level of the input signal but also of the preceding values on this last.



I2L : (Integrated Logic Injection), family of bipolar integrated circuits into high density of circuits. See MTL (Merged Logic Transistor).

IMPULSE: Abrupt variation of a physical size with return to its initial level. In the circuits, one can have impulses of tension or current.

INHIBIT : To inhibit, invalidate.

INPUT : Entry. Limit of entry to which a signal coming from outside is applied.

INSTRUCTION : Code or mnemonic indicating to a microprocessor the operation that it must carry out.

REVERSER : Logical circuit having an entry and an exit in which the level of the output signal is the complement of that applied to the entry.

INVERTER : Reverser, to see REVERSER.



Ko : Kilooctet = 1 024 bytes.



LATCH : (Bolt), rocks asynchronous being able to be charged by data when the enabling signal generally called E (for Enable) is active. This rocker allows the memorizing of data as long as another data does not come to replace it, i.e. as long as the Enable entry does not authorize it.

LCD : (Liquid Hook Display), bill-poster with liquid crystals.

LED : (Light Emitting Diode), diode which emits light when it is traversed by a forward current.

HIRING : (Memory Hiring), in French “position memory”. It is characterized by its address.

LOC-MOS: (Room Oxidation Complementary MOS), manufactoring process of the logical circuits based on the reverser and complementary, typical symmetry of family CMOS.

LOGIC : Together of rules defining a procedure of resolution of a problem.

BINARY LOGIC : Logic using two states, 1 or 0.

NEGATIVE LOGIC : Binary logic in which one makes correspond to a bottom grade (L) the logical state 1 and on a level the high (H) logical state 0.

POSITIVE LOGIC : Binary logic in which one makes correspond to a level the high (H) logical state 1 and on a bottom grade (L) the logical state 0.

STATIC LOGIC : Network made up of electronic doors (integrated circuits NAND, NOR, AND, OR) in opposition to the circuits with logic with relay.

LOOK AHEAD : Characteristic of a binary summoner in which the calculation of reserve is carried out by anticipation (all reserves are calculated simultaneously).

L.S.B. : (Least Significant Bit), bit of less weight. In a balanced digital code, it is the bit on the right.

L.S.D. : (Least Significant Digit), figure of less weight. In a balanced digital code, it is the figure on the right.

L.S.I. : (Broad Scale Integration), large-scale integration. Integrated circuits L.S.I. can include/understand 100 to 10 000 elementary doors on the same chip.



MAXTERME : Expression of a logical sum or are represented all the variables or their complements. For example,A_barre1.gif + B_barre.gif + c is a maxterme of the three variables a, b, c.

MEMORY : device intended to store the information which one will be able to read again thereafter. The electronic memories memorize the data in the form of bits.

BUBBLE MEMORY : Memory in which one uses magnetic bubbles to memorize information. The access of this memory is of the series type. It is faster and more reliable than the conventional magnetic storages.

MEMORY A DEFECT : Type of memory in which information circulates permanently according to a loop. This type of memory can be consisted registers with shift in which the last rocker is connected to the first.

MEMORY A TORI FERRITE : It is an old using type of memory of the ferrite cores, kinds of small toric electromagnets, to memorize information (see Digital Théorique 12).

DYNAMIC STORAGE : (A semiconductors), memory with semiconductors MOS, whose cells are consisted condensers. A periodic refill of the condensers (cooling) must be carried out to preserve the data.

READ-ONLY MEMORY : Memory whose contents are fixed once and for all and who can thus neither unobtrusive nor be modified, but only read.

STATIC STORAGE : (A semiconductors), memory with semiconductors generally of type MOS, whose cells are consisted bistable trigger circuits.

VOLATILE MEMORY : Memory in which information is lost when the supply is cut off.


MICROCIRCUIT : (Integrated), generally it is a circuit with semiconductor formed by diffusion in the network of a monocrystal. It is a question of diffusion of impurities so as to form within the circuit of the zones N or P.


MICROPHONE TO CONTROL : Microprocessor equipped with RAM, ROM and interface I / O and also called “ship sets”.

MICRO-ELECTRONICS : Science applied which studies the miniaturization of the electronic circuits (see MICROCIRCUIT).

MICROCOMPUTER : Miniaturized computer of very reduced size in opposition to minicomputer, computer of small size but of important capacity and of which the computing speed is higher.

MICROPROCESSOR : Central part of the microcomputer made of a single chip (see CHIP). It is consisted of the calculating unit, the unit of management and the lines of interconnections between these units.

MINICOMPUTER : Computer which can work on formed data of 8, 12, 16, 18, 24 or 32 bits and whose capacity is average.

MINTERME : One calls minterme or function unit of n variable a product of n variable or their complements. For example, the product aB_barre.gifc is a minterme if in logic considered one uses that three variables (a, b, c).

PUT : (Semi-conductor Insulator Metal), micro-electronic structure with semiconductor: insulator - metal.

MNEMONICS : Left acronym used to indicate an instruction in a programming language.

MNOS : (Metal Semi-conductor Oxide Nitride). transistor being used to manufacture the EEPROM.

MODULATION : Modulation of a parameter (amplitude, phase, frequency) of a sinusoidal wave, called carrying, at the rate/rhythm of information to be transmitted.

MODULATE : It is the number of states which a meter can take to return in an initial state. For example, a meter of module 8 passes by states 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2….

MONOSTABLE : (Multivibrator or rocks), this circuit has two states of which only one is stable. When an external signal the fact of passing from the stable state in an unstable state, it returns spontaneously in a stable state after a certain time of which the duration depends on the characteristics of the circuit.

MOS : (Semi-conductor Oxide Metal), micro-electronic structure semiconductor - metal.

MOS FET : (Metal Oxide Semi-conductor Field Effect Transistor), field-effect transistor made up of a basic structure semiconductor : oxidize - metal.

WORD : Together of variable bits of numbers. A byte is a word of eight bits.

M.S.B. : (Most Significant Bit), bit of weight more Ford. In a binary code, it is the bit on the left.

M.S.D. : (Most Significant Digit), figure of weight most extremely. In a number written in fixed-count code, it is the figure on the left.

M.S.I. : (Medium Scale Integration), medium-scale integration with 10 to 100 switching functions elementary NAND / NOR.

MTL : (Merged Logic Transistor), family of bipolar integrated circuits into high integration. The word “merged” (amalgamated) means that the great density of components inside these circuits results from fusion from transistors which, in the other processes of integration, remain separate. Certain manufacturers indicate the circuits of this family by abbreviation I2L (Integrated Injection Logic).

MULTIPLEXER : Circuit with several entries and only one exit. One or more entries of order make it possible to switch one of the input signals towards the exit.



NIBBLE : Group of four bits or half-byte.

N-MOS : Technology using of the transistors of the type N-MOS, i.e. with drain and source of the type N on substrate P.

NOISE : Noise or breath, to see NOISE.

NOT : NOT-circuit.

NOT : not, to see NOT.



OCTAL : Numbering system at base 8. It makes it possible to only represent the binary numbers with eight digits, by gathering the bits in sequences of three. For example, the binary value 001 110 010 011 will be written in octal 1623 or 0012 = 18, 1102 = 68, etc… The octal system however was supplanted in the computers by the hexadecimal system.

OFFSET : In the analogical circuits, it is, in an amplifier, the variation of tension necessary to the entry to put at zero the output voltage. In the digital circuits, it is an operational amplifier, the tension continues raised at exit when the entries are to 0.

OP-AMP : (Operational To amplify), to see AMPLIFIER OPERATIONAL.



LOGICAL OPERATION : Nonarithmetic operation which are carried out on one, two or several logical variables. For example, operation AND, OR, NAND, NOR.

OR : or, to see OR.

COMPUTER : System which can receive data, treat them and provide the result.

FLOW CHART : Diagrammatic representation of the course of a program showing in the form of an arrow diagram each operation materialized by geometrical squares, rhombuses… or other forms. One finds sometimes name PROCESS CHART.

OSCILLATOR : Circuit astable which generates a rectangular signal, used to synchronize the circuits in synchronous logic. There are also sinusoidal oscillators.

OR : Elementary switching function still called logical sum such as a OR b = S is written a + b = S.

OUTPUT : Exit.

OVERFLOW : Mean “capacity overshooting”. There is “overflow” when one exceeds the maximum capacity of a meter for example, or when the result of an arithmetic operation exceeds the capacity of the register in which it must be stored.



PARALLEL : (In parallel), transmission or simultaneous treatment several information, in opposition to series.

PASS-TRANSISTOR : Complementary MOS FET in parallel inserted in a line of transmission. They are used as bidirectional electronic switches and are ordered by their grids.

PERIOD : Duration of a cycle in seconds. The reverse of the period is the frequency which is expressed in hertz.

PLA : (Programmable Logic Array), formed integrated circuit of logical doors which can be programmed by the user.

PM : (Phase Modulation), phase modulation. (See MODULATION).

PORT : (End of a bus line by which information forwards towards a system.

CARRY : Combinative elementary logical circuit still called SPOILS in English.

PRESET : Limit of asynchronous entry which makes it possible to impose on the exit of a circuit the level H.

LOGICAL PRODUCT : Result of the logical operation AND. The symbols used are (X ; . ; ^ or Ç). Sometimes, the symbol is omitted.

PROGRAM : Continuation of end to end put instructions or sequence allowing to carry out a complex operation automatically.

PROM : (Programmable Read Only Memory), programmable memory with reading only authorized. With the difference of the traditional ROMANIANS, they can be programmed by the user (TO USE) then used like ordinary ROM.

PROPAGATION DELAY : Delay of propagation. Time put by a signal to cross a door or a circuit (of the entry at the exit).



PULSATE LENGTH / PULSATES WIDTH : Lasted of the impulse measured between the moment when the level observed reached 50 % of the high level (rising or positive face) and moment when the level passes by again by this same value of 50 % at the time of the downward or negative face.



RAM : (Random Memory Access), random access memory. Generally, it is about a memory with semiconductors LSI with read/write where one can read and write data.

READ : To see, extract from a memory or a register information stored in the form of bits or from byte.

REFRESH : Cooling, periodic refill of the condensers constituting the positions memories of the dynamic storages.

REGISTER : Circuit generally formed by a whole of rockers to store a byte temporarily.

REGISTER A SHIFT : Register whose contents can be shifted of one or more positions towards the right-hand side or the left. Information can enter or leave, in series or parallel, according to the type of the register.

DYNAMIC REGISTER : Register in which the conservation of the data requires a periodic regeneration of the electric charges of the cells carried out by shift by means of two or several clocks.

STATIC REGISTER : Register whose cells are consisted synchronous rockers. The static register is a circuit more complex than the dynamic register, but it has the advantage of preserving the data even in the absence of clock signal.

RELAY : Electromagnetic component whose one or more couples of contacts open or is closed under the action of a magnetic field obtained by sending a current in the rolling up of a reel.


CARRYFORWARD : (Or retained), delivered signal when the result of an operation on several figures is equal or higher than the base of the selected numbering system. For example, in decimal code, the sum 8 + 7 gives like result 5 with a carryforward of 1. The exit or the entry of the carryforward in a circuit summer as well as the signal generated by a meter is often indicated by the English term CURRY.

RESET : Entry of handing-over to 0 of a logical circuit. While applying to this entry an active level, the exit of the circuit passes on the level L (RESET is synonymous with CLEAR).

RIPPLE THROUGH: If a whole of summoners is considered, this term means that the carryforward is propagated of a summoner to the following. One obtains a method of relatively slow addition thus since, before having the exact result, it is necessary to wait until the carryforward was propagated first with the last summoner. To accelerate this operation, one uses anticipated reserve, in English “look ahead curry” (see LOOK AHEAD). For a meter, ripple through means that the propagation of the clock signal is carried out in an asynchronous way (see ASYNCHRONOUS).

SMALL CHANNEL TIME : (Boarding Time), time necessary so that the tension passes from the bottom grade at the high level. This time is measured between the moments when the tension passes from 10 % to 90 % of the high level.

ROM : (Read Only Memory), Memory with reading alone. The data are recorded there by the inalterable manufacturer of manner.



LOGIC DIAGRAM : Chart of a system while using for each elementary function or logical operator his notation symbolic.

SYNOPTIC DIAGRAM : Chart in which the fundamental parts of a system are symbolized by rectangles or squares connected to each other by arrows indicating the direction of course of the signals. The goal of this type of diagram is to highlight da way the clearest possible functional structure of a whole of circuits.

SCHOTTKY : (Diode), diode made up of a semiconductor and a metal. It has a very low capacity of junction, from where its functioning employment in the circuits at very high frequency and whose commutation rate is high.

SEQUENTIAL : (Circuit), logical circuit in which the level of the exits at a given moment depends on the former levels of the entries. The meter is a sequential circuit since it “remembers” the pulse repetition frequency which arised at its entry of counting since the restoring.

SERIES : (Operation in series), transmission or processing of several data ones after the others (in opposition to parallel).

SET : Entry of setting to 1 of a logical circuit ; by applying an active level to him, the exit of the circuit is brought to the high level.

THRESHOLD : Minimal value of the tension (or the current) which it is necessary to apply to a device so that it changes state or rocks).

SLSI : (Super Broad Scale Integration), integration on very a very large scale, more than 10 000 logical elementary NAND, NOR doors…

SOFTWARE : Program (or software) of a machine or a numerical system, i.e. the whole of the instructions formulated in a language adapted to the machine and recorded in memories.

SUMMONER : Circuit able to carry out the sum of two binary numbers. It is called half-summoner or half-adder (half adder) if it cannot take account of reserve coming from another summoner. It is called complete summoner or full adder (full adder) if it has an additional entry for reserve.

COMPLETE SUMMONER : Summoner of binary numbers having an additional entry for reserve coming from the preceding sum.

LOGICAL SUM : Result of the logical operation OR. The sum is worth 1 if one or more variables are worth 1 ; on the other hand, if all the variables are worth 0, the result is 0. The logical sum is indicated by the symbols +, V, U.

FAN-OUT : A many of the same doors technology than can order a circuit.

SOURCE: (Of a FET), electrode constituting one of the two ends of the channel of conduction of the FET; the other electrode is called drain.

IF : (Small Scale Integration), integration on weak scale about ten logical elementary NAND / NOR doors.

STAND-ALONE SYSTEM : (Microcomputer, microprocessor), operative autonomous system inside a computer. The system includes/understands a software made up of an assembler, an editor and a program of debugging (see ASSEMBLER, EDITOR, DEBUG).

STEERING LOGIC : Logic whose operation is based on the order of switches, relay or doors of transmission. It is a more modern version of old “the Switching logic” whose operation was only based on the operation of mechanical switches or relay in opposition to the static logic carried out with networks of doors (networks of circuits micro-electronic, NAND, NOR, AND, OR…).

STICK DIAGRAM : Diagrammatic representation simplified in the form of matrix made up of horizontal and vertical lines in which all the identical elements are indicated only only once. One will represent, for example, the logical doors or the diodes simply by a connection materialized by a point.

SWITCH : Switch, reverser or electric switch of circuit.

SWITCHING LOGIC : Logic with switches whose operation is based on the operation of mechanical switches or relay. Sometimes, one uses the same denomination to indicate the “steering logic”, (see STEERING LOGIC).

SYNCHRONOUS : Is known as “synchronous”, a device ordered by a regular sequence of impulses following one another like the beats of a clock. The signal produced by the generator of impulses is called signal clock.



COUNT OF OPERATION : Count in which is indicated the correspondence between the logical levels of entry and those of exit of a logical circuit. In the tables of operation, the logical levels are represented by the letters H (High) and L (Low).

TRUTH TABLE : Count in which is indicated the correspondence between the logical states of entry and those of exit of a logical circuit. In the truth table, the logical states are represented by the binary digits 0 and 1.

ACCESS TIME : (Of a memory), time which passes between the moment when a data is requested from the memory and the moment when the data is available; it is also the minimal time during which the data must be present to be written in memory.

THREE STATE : Denomination used by certain manufacturers in the place of TRI-STATE (see TRI-STATE).

THRESHOLD : Threshold, to see THRESHOLD.

TRANSDUCER : Transducer, to see TRANSDUCER.

TRANSDUCER : Device which transforms the physical size of a signal into another physical size, function of the preceding one. For example, the microphones, the loudspeakers, the cathode ray tubes, the photosensitive cells, the thermosensitive elements… are transducers.

TRANSISTOR : (Bipolar, traditional), active component with semiconductor made up of three zones successively N, P, N or P, N, P. The bipolar transistor functions out of amplifier ordered while running. See BIPOLAR (technology, integrated circuit).

TRIGGER OF SCHMITT : Rock bistable having a hysteresis loop (see HYSTERESIS). It is used to give in the shape of the parasitized signals or whose decrease or boarding time is too high.

TRI-STATE : Name allotted by the National Semi-conductor Corporation to certain integrated circuits. The exit can take three states there: low, high and high impedance. The third state is used to isolate the exit when it is connected to one or more exits.


TTL : (Transistor Logic Transistor), logical family of bipolar integrated circuits (see BIPOLAR).



LOGICAL AND ARITHMETIC UNIT : Together of circuits which carry out the arithmetic and logical operations fundamental : addition / subtraction, division / multiplication by two, complements, comparison of values, meeting or logical sum OR, intersection or logical product AND, complementation or logical inversion.

UP / DOWN COUNTER : Meter/discounting machine in which the impulses of entries can increment or décrémenter the meter depending on the state of one of its entries of order called UP / DOWN.

USER : English term usually employed to nominate a person using a computer or intervening actively in the preparation of the programs.



BOOLEAN LOGICAL VARIABLE : Variable which can take only two states: yes or not, high or low, opened or closed, 0 or 1


VLSI : (Broad Very Scale Integration), very large-scale integration: more than 10 000 logical elementary NAND / NOR doors.




WRITE : To write, transfer information in the form of bits or of byte in a box memory or a register.



XOR : (Or EX-OR), OR Exclusive.


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