# Theory of Computer Science Basic components of a computer

## Presentation on theme: "Theory of Computer Science Basic components of a computer"— Presentation transcript:

Theory of Computer Science Basic components of a computer
Gate (logical Gate) Flip-flop Register Memory Arithmetic-Logic Unit -ALU Central Processing Unit - CPU Decoder and encoder

Theory of Computer Science - Basic components of a computer
Electronic parts (transistors, resistors) -> Gates Gates -> Flip-flop Gates -> Decoder and encoder Gates + Flip-flops -> Register Gates + Flip-flops -> Memory Gates + Flip-flops -> Arithmetic-Logic Unit - ALU Registers + Memory + ALU + Bus connection -> Central Processing Unit - CPU CPU + Memory + Input/Output devices -> computer

Theory of Computer Science - Basic components of a computer
Central Processing Unit - CPU

Theory of Computer Science - Basic components of a computer
Gates Binary variable ● Binary arithmetic is the basis notation in the computer technique ● Binary variable have only 2 values called bits: 0 and 1 ● The basic components of the computer realize the operations on single bit ● Basic Gates: ● the negation NOT ● the logical sum OR ● the logical product AND ● the negation of the sum NOR ● the negation the products NAND ● the sum modulo 2 XOR

Theory of Computer Science - Basic components of a computer
The Gate of negation – NOT ● The logical function: ● The change of the entrance signal x on opposite

Theory of Computer Science - Basic components of a computer
The Gate of logical sum OR ● The logical function: z = x + y ● Exit signal y equal 0 only when there are 0 on both entries x y z 1

Theory of Computer Science - Basic components of a computer
The Gate of logical sum OR ● The logical function: z = x + y ● Exit signal y equal 0 only when there are 0 on both entries

Theory of Computer Science - Basic components of a computer
The Gate of logical product AND ● The logical function: z=xy ● Exit signal y equal 1 only when there are 1 on both entries x y z 1

Theory of Computer Science - Basic components of a computer
The Gate of logical product AND ● The logical function: z=xy ● Exit signal y equal 1 only when there are 1 on both entries

Theory of Computer Science - Basic components of a computer
The Gate of negation of the sum NOR ● The logical function: ● Exit signal y equal 1 only when there are 0 on both entries x y z 1

Theory of Computer Science - Basic components of a computer
The Gate of negation of the sum NOR ● The logical function: ● Exit signal y equal 1 only when there are 0 on both entries

Theory of Computer Science - Basic components of a computer
The Gate of negation the products NAND ● The logical function: ● Exit signal y equal 0 only when there are 1 on both entries x y z 1

Theory of Computer Science - Basic components of a computer
The Gate of negation the products NAND ● The logical function: ● Exit signal y equal 0 only when there are 1 on both entries

Theory of Computer Science - Basic components of a computer
The Gate of sum modulo 2 XOR ● The logical function: ● Exit signal y equal 1 only when there is one on exactly one entry x y z 1

Theory of Computer Science - Basic components of a computer
The Gate of sum modulo 2 XOR ● The logical function: ● Exit signal y equal 1 only when there is one on exactly one entry

Theory of Computer Science - Basic components of a computer
The de Morgan statement: x y 1

Theory of Computer Science - Basic components of a computer
The de Morgan statement:

Theory of Computer Science - Basic components of a computer
The flip-flop ● The system having of 2 stable states (Q and negation of Q) ● The changes of state, from one to second, can be made by short impulse to the flip- flop, from outside ● Uses to remember information, where capacity is equal of 1 bit (using 1 flip-flop we can store 1 bit information only)) ● not only current values on enter, decide what is the value on exit of flip- flop, but also the previous state of the flip-flop

Theory of Computer Science - Basic components of a computer
The SR flip-flop ● The entry placing s (set) ● The entry resetting r (reset) ● The state, when both entries equal 1 is forbidden

Theory of Computer Science - Basic components of a computer
The SR flip-flop - 0 and 0 doesn’t change anything

Theory of Computer Science - Basic components of a computer
The construction of the flip-flop sr – example of realization with uses of 2 gates (nor)

Theory of Computer Science - Basic components of a computer
The construction of the flip-flop sr remember that 1 and on entry is forbidden

Theory of Computer Science - Basic components of a computer
The flip-flop jk j k Qn Qn+1

Theory of Computer Science - Basic components of a computer
The flip-flop jk

Theory of Computer Science - Basic components of a computer
Register ● The set of flip-flops, designed to storage, the digital information ● Sequence and Parallel ● Realization of the writing to the parallel register: - with preliminary resetting - with the pushed entry

Theory of Computer Science - Basic components of a computer
Register Example of parallel register with preliminary resetting Before we send data from one register to next, it is necessary to reset, the previous values, stored in second register.

Theory of Computer Science - Basic components of a computer
Register Example of parallel register with the pushed entry Resetting is made automatically: When is 1 we have signal set When is 0 we have signal reset

Theory of Computer Science - Basic components of a computer
Bus connection ● Set of wires, attached in the moment of beginning, of sending the value, to individual exits, of the flip-flops and source ● Applied for making possible of sending the values, between several registers ● The signal is spreads through the wire with the limited speed ● The bus connection is so-called: the long line

Theory of Computer Science - Basic components of a computer
The distortion of signals on the Bus connection

Theory of Computer Science - Basic components of a computer
Horizontal and impulse signals

Theory of Computer Science - Basic components of a computer
Sending the value between Registers (C) → A wyc, wea from (C) in to A (C) → B wyc, web wy – horizontal signal we – impulse signal

Theory of Computer Science - Basic components of a computer
Coding and decoding – change from one way, of representation the information, to different. The decoder

Theory of Computer Science - Basic components of a computer
Coding and decoding Using binary values, we can store data in 2 ways: 1. For a set of data, we have the some number of binary values – so it’s one to one. 2. For a set of data, we have combination of binary values. So having n binary values, we can write n data, using first way, and using second way. Using second, way we can write more different data, but we need to code and decode the information.

Theory of Computer Science - Basic components of a computer
The encoder The table of dependence for encoder and decoder

Theory of Computer Science - Basic components of a computer
The equation of variables, for encoder and decoder z0=L1+L3+L5+L7 z1=L2+L3+L6+L7 z2=L4+L5+L6+L7

Theory of Computer Science - Basic components of a computer
The realization of encoder and decoder with the use of gates

Theory of Computer Science - Basic components of a computer
The summary ● the basis of binary arithmetic ● the logical gates ● the flip-flops ● the registers ● the bus connection ● the encoders and decoders

Theory of Computer Science - Basic components of a computer
The Arithmetic-Logic Unit - ALU ● Part of processor that make arithmetic and logic operation on data. ● The basis of binary arithmetic: In computers is applied the binary system of the representation of integer values, (the mode of replenishment, supplement up 2) ● The basic operation in ALU is the addition ● Subtraction is addition of the opposite number ● The multiplication is the multiple addition of the same number

Theory of Computer Science - Basic components of a computer
Basic components of Arithmetic-Logic Unit – ALU ● Two techniques of the realization of the operation on machine words: (n bits n – length of register ) ● sequence (old one – bit by bit) ● parallel (operation on n bits in the some time) ● The single module (elementary operator) operates on the single bit of the arguments) ● The register of the accumulator, keeps the results of the operation (sometimes is also one of value)

Theory of Computer Science - Basic components of a computer
The versions of the Arithmetic-Logic Unit ● 2-entrance ● With the accumulator as the argument

Theory of Computer Science - Basic components of a computer
Arithmetic-Logic Unit ● With the accumulator as the argument

Theory of Computer Science - Basic components of a computer
Operations in Arithmetic-Logic Unit - ALU ● The rewriting przep (in) → AK ● The negation not ~(in) → AK ● Logical sum or (Ak) Ú (in) → AK ● Logical product and (Ak) ^ (in) → AK ● The addition dod (Ak) + (in) → AK ● The subtraction ode (Ak)-(in) → AK weak

Theory of Computer Science - Basic components of a computer
The example realization of Arithmetic-Logic Unit – ALU for the single bit:

Theory of Computer Science - Basic components of a computer
The operating memory Definition of the operating memory: The technical device, enabling of receiving and recording the data, and then their inserting, at any moment, to the existing computational process. Devices that store the programs and data, required by the processors.

Theory of Computer Science - Basic components of a computer
The operating memory - Feature of computer memory: Capacity [Byte – B 1KB =1024B 1MB=1024KB 1GB=1024MB] Performance Access time (of writing and reading) Transfer rate Physical type Semiconductor [ROM, RAM, PROM, EPROM, EEPROM] Magnetic [hard drive disc - HDD] Optical [DVD] Physical characteristic volatile / nonvolatile erasable / nonerasable Location [CPU Internal External]

Theory of Computer Science - Basic components of a computer
Symbolic of computer operating memory

Theory of Computer Science - Basic components of a computer
Sending the value between registers and memory – few examples (S) → (A) writing to the memory ((A)) → S reading from memory (S) → writing to the memory to address 7 (3) → S reading from memory from address 3 5 → 2 writing the value 5 to the memory to address 2 (3) → 2 copy data from memory address 3 to the memory to address 2

Theory of Computer Science - Basic components of a computer
Sending the value between registers and memory – few examples (R1) → R2 sending value from R1 to R2 ((R1)) →R2 value in R1, is an address of data, that is in the memory, and we need to send this data - this value, to R2 (((R1))) →R2 value in R1, is an address of data1 in the memory, and this data1 is an address of data2 in the memory, and we need to send this data2 - this value, to R2 R1 → R2 impossible to send R1 to R2 – we can only send the value from R1 (R1)

Theory of Computer Science - Basic components of a computer
Semiconductor memory Volatile: ● RAM (Random Access Memory) – (writing and reading possible) Nonvolatile: ● ROM (Read Only Memory) ● PROM – (one chance to write data then only reading possible) ● EPROM, EEPROM (writing and reading possible many times)