Page 378 - FUNDAMENTALS OF COMPUTER

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378 Fundamentals of Computers NPP

5.1 Architecture of a Simple 5.1 EH$ qgnb àmogoga H$m Am{H©$Q>o³Ma
Processor

5.1.1 A Simple Computer Organisation 5.1.1 qgnc H$åß`yQ>a Am°J}ZmBOoeZ
Operation of a simple Computer can be EH$ qgnc H$åß`yQ>a Ho$ Am°naoeZ H$mo na\$m°åS>©
specified with the help of sequence of _mBH«$moAm°naoeÝg Ho$ {gŠd|g H$s ghm`Vm go ñno{g\$m`
microoperations performed. Register transfer
statements may be used to describe the {H$`m Om gH$Vm h¡& a{OñQ>a Q´>m§ñ’$a ñQ>oQ>‘|Q> Am°naoeÝg
operations. H$m dU©Z H$aZo Ho$ {bE Cn¶moJ {H$¶m Om gH$Vm h¡&
The organisation of the computer can be H$åß`yQ>a Ho$ Am°J}ZmBOoeZ H$mo {ZåZmZwgma n[a^m{fV
defined by the following: {H$`m Om gH$Vm h¡:

1. The set of internal registers. 1. B§Q>Z©c a{OñQ>g© H$m goQ>
2. Function of each register. 2. àË`oH$ a{OñQ>a Ho$ \§$ŠeÝg
3. The sequence of microoperations. 3. _mBH«$moAm°naoeÝg Ho$ {gŠd|g
4. The timing and control structure that 4. Q>mBq_J Ed§ H§$Q´>moc ñQ´>ŠMa Omo _mBH«$moAm°naoeÝg Ho$
initiates the sequence of microoperations. {gŠd|g H$m àma§^ H$aVm h¡&
5. The instruction set of computer. 5. H$åß`yQ>a H$m B§ñQ´>ŠeZ goQ>
A user writes a program to perform certain {d{eîQ> Q>mñH$ Ho$ na\$m°_© hoVw `yOa àmoJ«m_ {cIVm
task. A program is a sequence of instructions. h¡& B§ñQ´>ŠeÝg Ho$ {gŠd|g H$mo àmoJ«m_ H$hVo h¢& {~Q²>g Ho$
An instruction is a pattern of bits which initiates
a sequence microoperations. The instruction is n¡Q>Z© EH$ {ZX}e hmoVo h¢, Omo _mBH«$moAm°naoeÝg H$m {gŠd|g
kept in the main memory. àma§^ H$aVo h¢& B§ñQ´>ŠeÝg H$mo _oZ _o_moar _| aIm OmVm h¡&
Instruction is brought from memory to B§ñQ´>³eZ, _o_moar go àmogoga VH$ cm`m OmVm h¡&
processor. The processor has a timing and àmogoga Ho$ nmg Q>mBq_J Ed§ H§$Q´>moc ñQ´>ŠMa hmoVm h¡, Omo
control structure which interpretes the binary
code of the instruction. This structure issues B§ñQ´>ŠeÝg Ho$ ~m`Zar H$moS> H$mo B§Q>a{àQ> H$aVm h¡& {XE JE
timing and control signals to initiate sequence B§ñQ´>ŠeÝg EŠOrŠ`yQ> H$aZo Ho$ {cE, ñQ´>ŠMa _mBH«$moAm°naoeÝg
of microoperations to execute the given {gŠd|g àma§^ H$aZo hoVw Q>mB_ Ed§ H§$Q´>moc {g½Zëg ^oOVm
instruction. When data and instruction both h¡& O~ S>mQ>m Ed§ B§ñQ´>ŠeÝg XmoZm| H$mo EH$ hr _o_moar _| aIm
are kept in the same memory, the concept is
called stored program concept. OmVm h¡ Vmo Cgo ñQ>moS>© àmoJ«m_ H§$goßQ> H$hVo h¢&
Instruction Set B§ñQ´>ŠeZ goQ>
Processor can interprete binary infor- àmogoga Ho$dc ~m`Zar gyMZmAm| H$mo B§Q>a{àQ> H$a gH$Vm
mation only . Therefore a set of bits is applied h¡& Bg{cE {deof Am°naoeZ hoVw {~Q²>g Ho$ goQ> àmogoga _|
to the processor for a particular operation. This
binary number given to the processor for a Eßcm` {H$E OmVo h¢& {deof Q>mñH$ hoVw àmogoga H$mo ~m`Zar
particular task is called instruction code. Z§~a ^oOo OmVo h¢, {OÝh| B§ñQ´>ŠeZ H$moS> H$hm OmVm h¡&
Instruction codes are stored in the main B§ñQ´>ŠeZ H$moS²>g H$mo _oZ _o_moar _| ñQ>moa {H$`m OmVm
memory. Processor featches these, instruction h¡& àmogoga BZ B§ñQ´>ŠeÝg H$mo n‹T> H$a CÝh| EŠOrŠ`yQ>