Transcript CPU-MEMORY
• CPU
•MEMORY
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CPU
Its manage everything held in memory
so that the machine keeps track of
what is stored, where it is and what
type of data it is so that there is no risk
of the program instruction being mixed
up with output data or any other data.
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Its constitute a microprocessor which is a single microchip
attached (which is the main electronic board in the
microcomputer)
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The processor, also called the microprocessor or
CPU (for Central Processing Unit), is the brain
of the PC. It performs all general computing tasks
and coordinates tasks done by memory, video,
disk-storage, and other system components.
The CPU is central located on the system board.
The CPU is a very complex chip that resides
directly on the motherboard of most PCs, but may
instead reside on a daughter-card that connects to
the motherboard via a dedicated specialized slot.
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The CPU is certainly the most important PC
component. CPU stands for Central
Processing Unit. Let us briefly study that
name:
•It is processor, because it processed data
•It is central, because it is the center of data
processing.
•It is a unit, because it is a chip which,
contain millions of transistors.
Without the CPU, there would be no PC!
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CPU REGISTERS & THE PROCESSING CYCLE
Within the CPU are a number of high speed, special-purpose
memory units called registers which are used to store data read
from memory.
Instruction registers to store instruction
Data registers to store data
Program counter registers- to enable the processor to
perform the instructions in the correct order;
Stack pointer register, which points to a last In First Out
(LIFO) stack holding return addresses when an interrupt
occurs;
Flag which indicate the outcome of operation-4Exp arithmetic
operation may cause overflow
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(Primary storage) -it is Volatile
{ROM,RAM}
ALU
CU
(Non volatile)
HARDISK
CD-ROM
FLOPPY-DISK
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CENTRAL PROCESSING UNIT
Consisting of TWO component:
(I) Arithmetic Logic Unit (ALU)
(ii) Control Unit (CU)
ALU
One of the most obvious processes through which
input data has to go is that of calculation
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CU
Control unit & it exercises control over all the other
components which exist without the system
Instruct the input device to read the quantity and the
unit
price and to store them in main memory.
Instruction the ALU to take copies of the two values
and multiply them together to obtain the gross cost
and to store this values back in main memory
Instruct the ALU to obtain a copy of gross cost and
calculate 10%of this figure and to store the result,
discount, into main memory
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MAIN MEMORY
These memory server a number of separate functions
Function as a working storage which holds
data currently being processed.
Storage area where output data can be
held before it is transferred to the printer
or to some other output device.
It will hold the program currently being
executed.
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SECONDARY STORAGE
Floppy-disks and CD-Rom being used for
Secondary storage and also with the use of the
internal hard-disk
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MEMORY
(Storage capacity Elements)
“Refer chapter One”
What is character addressable storage?
TYPES OF MEMORY
There are several different type of
primary storage
•Random Access Memory (RAM)
•Read Only memory (ROM)
•Processor Cache Memory (PCM)
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RANDOM ACCESS MEMORY
Can be both from and written to and
any location can be accessed
independently this in why it is called
(Random Access Memory).
TYPE OF RAM
•DIMM (dynamic memory)
•SIMM (static memory)
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DDR
DRAM
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ROM
Typically used for starting up a computer,
and for computer with simple continuous
control functions such as PLCs
(programmable Logic Controllers)
TYPE OF ROM
PROM:
programmable Read-Only memories that have their
contents created electrically by selectively blowing
fused links
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EPROM:
erasable programmable Read-Only memories.
Have their contents created electrically & erased
optically by shinning Ultraviolet light through a
window on the top of each integrated circuit
EEPROM:
electrically erasable programmable read only
memories. combines the advantages of being
updateable in position,using normal computer
facilities and controls.
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Processor Cache Memory
This is a small amount (512 kilobytes
on the Pentium-III processor) of
fast,memory placed between the
processor and main-memory
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SIMM
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