how a processor works 2

Monday, March 23, 2009

Step 1: Push Key 2

A
Pressing the 2 key alerts the microprocessor and signals the Prefetch Unit to ask the computer's main memory for a specific instruction on the new data since there is nothing about it in the Instruction Cache.

B
The new data instruction comes into the microprocessor through the Bus Unit from the computer's main memory and gets stored in the Instruction Cache, where it is assigned a code "2=X".

C
The Prefetch Unit then asks the Instruction Cache for a copy of the code "2=X" and sends it to the Decode Unit for further processing.

D
In the Decode Unit the instruction "2=X" is translated or decoded into a string of binary code that is sent off to the Control Unit and the Data Cache to tell them what to do with the instruction.

E
Because the Decode Unit figured out that the number 2 was to be stored for the future in the Data Cache, the Control Unit now performs the instruction for "2=X." This causes the number 2 to be sent to an address in the Data Cache called "X," where you see it waiting for further orders.