Control Unit in CPU

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Face
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Control Unit in CPU

Post by Face » Fri Apr 09, 2010 8:33 pm

Control Unit in CPU

CPU contains

*Arithmetic logic unit.It handles the logical operations..I will ask some more about this in a new topic.

*Control unit-handle the flow of data between CPU & Main memory.what is this CU?how it control the data flow.?please tell me the basic architecture about this..

*Registers-Special memory area inside processor.The number of Bites which can store in a REGISTER called word size.please explain about word size....(i will read about REGISTERS & then ask questions about them future..)
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Re: Control Unit in CPU

Post by Neo » Sat Apr 10, 2010 4:56 am

*Control unit-handle the flow of data between CPU & Main memory.what is this CU?how it control the data flow.?please tell me the basic architecture about this..
CU is basically responsible on handling the most important 2 buses (set of pins wired from one chip to the other which is used for communication between the chips in simple terms) connected to CPU.
  1. Address bus
  2. Data bus
The main operations of CU is Memory Read and Write.

Memory Read
Think that we are going to write something to memory at memory address 0xE0008056. Here is the procedure.
  • Write 0xE0008056 to address bus
  • Read value from data bus
Memory Write
Say, we are going to write value 100 to memory address 0xE0008056. Here is the procedure.
  • Write 0xE0008056 to address bus
  • Write 100 to data bus
I think you are clear on that. Also note that, in modern computers, RAM chips are wired to CPU through another control IC called North Bridge. North bridge works as an abstraction layer to CPU on memory handling. So the CPU doesn't need to know whether your RAMs are SDRAM, RDRAM, DDR-I, DDR-II or DDR-III. North Bridge handles everything. If you have a look your motherboard, you can easily identify this chip.
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*Registers-Special memory area inside processor.The number of Bites which can store in a REGISTER called word size.please explain about word size....(i will read about REGISTERS & then ask questions about them future..)
Word is a term for the natural unit of data used by a particular computer design. A word is simply a fixed sized group of bits that are handled together by the system. The number of bits in a word is called word size or word length and it is an important characteristic of computer architecture.

If you refer your CPU is a 32-bit one, that means you have 32-bit registers in the CPU.
Your CPU is capable of doing operations like addition, subtraction, etc... on these 32-bit registers at ones.

Some of the common CPU architectures with different word lengths are given below.
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Re: Control Unit in CPU

Post by Face » Sat Apr 10, 2010 7:51 am

Thank you friend.now i have a clear picture on this CU read & write controls.i referred some wed to get more ideas.
My processor is "Dual core Desktop Intel Pentium processor" one.Intel 64 architecture.then this is my word size right?

Friend I have a little question.When we download software there are 32X & 64X.is This deviation according to the processor architecture?according to the my processor I should choose 64X software...But normally I get 32X software...
can you tell me what happen If any one install 64X software to a 32x computer..?
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