Qarshi filiali tt va kt fakulteti

Protsessor buyrug’i

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  Buyruq-bu qanday harakat bajarilishi haqidagi maxsus ikkilik kodli so’zlar birligidir.
  

Markaziy protsessor (cpu)

Protsessorning ishlashi asosan beshta quyidagi bosqichlardan iborat:

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  Buyruqni o’qish;
  
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  Buyruqni deshifrlash;
  
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  Operandlarni o’qish;
  
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  Buyruqni bajarish;
  
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  Natijani yozish;
  

Buyruqlar tizmi

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  Buyruqlar tizimi-bu kompyuter ishlatadigan buyruqlar ro’yxati bo’lib, ular yordamida dasturchi ma’lumotlarga ishlov berishning o’z algoritmini ishlatadi.
  

Buyruqlar tizimi arxitekturalari:

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  CISC (Complex Instruction Set Computer)-to’laroq buyruqlar to’plami;
  
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  RISC (Reduced Instruction Set Computer)-qisqartirilgan buyruqlar to’plami
  
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  VLIW (Very Long Instruction Word)-o’ta katta uzunlikdagi buyruqlar
  

CISC (Complex Instruction Set Computer)

To’laroq buyruqlar to’plami kompyuteri (CISC) - bu bitta ko'rsatmalar bir nechta past darajadagi operatsiyalarni bajarishi mumkin bo'lgan yoki ko'p bosqichli operatsiyalarga yoki bitta ko'rsatmalar doirasida rejimlarni aniqlashga qodir bo’lgan buyruqlar to’plami.

RISC (Reduced Instruction Set Computer)

Qisqartirilgan buyruqlar to’plami (RISC) - eng qisqa vaqt ichida eng oddiy ko'rsatmalar bilan hisoblash vazifalarini bajarishga mo'ljallangan har qanday mikroprotsessorlar oilasidan foydalangan holda ma'lumotlarni qayta ishlovchi buyruqlar. RISC - bu CISC-ning teskarisi

Risc vs Cisc

RISC	CISC
Focus on software	Focus on hardware
Uses only Hardwired control unit	Uses both hardwired and micro programmed control unit
Transistors are used for more registers	Transistors are used for storing complex Instructions
Fixed sized instructions	Variable sized instructions
Can perform only Register to Register Arithmetic operations	Can perform REG to REG or REG to MEM or MEM to MEM
Requires more number of registers	Requires less number of registers
Code size is large	Code size is small
An instruction execute in a single clock cycle	Instruction takes more than one clock cycle
An instruction fit in one word	Instructions are larger than the size of one word