The processor is certainly one of the most important parts of any PC so much that can be termed as the brain. Is responsible for running applications, interact with the keyboard, mouse, etc. Its role is key within any PC as if this element does not work properly the entire system suffers.
Its operation, you can see, in simplified form, divided into the following steps
Read instruction. Any program like make is composed of instructions and data. The first indicates the processor tasks should be carried out on the latter. An instruction, for example, is the sum of A and B where both A and B are data. In short, the first step is to read an instruction from memory.
Read the data associated with that instruction. After reading the statement, and analyzed the data to be processed, these are read from memory. Continuing the above example, A and B would be read from memory.
Processes information and data is written to memory. the operation is performed. Depending on the instruction, the result can be written in memory, or be stored within the processor, in a record of it for later use.
It goes to the next instruction. Typically move to the next instruction. But not all are equal and some may change the program flow. For example, one may decide that the above instructions are repeated until a certain condition is not met.
Processors, the PC, which use is known as von Neumann architecture. In it, both the data and the instructions are in the same memory.
On a PC, there is no single device that we call memory, but really this is a multi-level hierarchical system. When the computer is off, data and programs are stored on the hard disk as soon as the PC is turned on is written into the RAM that is where the processor can read.
The RAM is thousands of times faster than the hard drive and therefore is ideal for storing programs when executed.
Using the von Neumann architecture makes the speed at which read and write data and instructions to be very important. It may be the case that all the processor be waiting to receive data being blocked until they reach not machine. The micro is very fast and is no stranger to stay waiting for data and instructions.
The solution taken by engineers processors to accelerate this link is to add more levels to the memory hierarchy. several memory levels, which are called cache within the processor are inserted.
Each level, you try to store the values most are consulted, making successive readings more fluid. The role of the cache memory is so simple that the data are as close as possible to where they will be processed. This element is very important and so is often given its size when we consult the technical specifications of the micros.
The flow of instructions and data is not the only thing to accelerate, it is also desirable that the processing of each of them as fast as possible.
To achieve this a processor has a single block functions to work with if it can be composed of several. When an instruction is processed, it is divided to use the various blocks of the processor. Really what it does is split a very complex instruction into smaller parts known as microinstructions.
Thus even a processor is capable of running several of these instructions per clock cycle. It all depends on the architecture that has been used.
The part of sync processor responsible for this whole process is the control unit.
The micro has inside a small memories called records. In these, data operations are to be stored is entered, the operation is executed and other information of these records is returned.
If operations are complex functional blocks are adapted as ALUS and FPUs they are used.
With the emergence of new instruction sets, aimed at accelerating mathematical processed as you can find in multimedia or generating three-dimensional graphics applications, the number of these records and their size has increased exponentially.
Not all instructions are the same type but there are some that depending on certain conditions can jump to other parts of the program. Processors play with pre-empt the results, sometimes you run the first and third operation following example before the second is done, but it conditional statements can change everything.
This makes good predictor jump is important so that the processor can continue to operate at full power.
In essence processors of a current computer work the same way as one of 20 years ago, what has changed are the optimizations that have been made.
Including the ability to segment applications, the use of cache memory or predict jumps are some of the highlights.