Instruction sets

• All microprocessors come with a pre-programmed set of instructions. These instructions are hard-wired into the microprocessor's circuitry and provide for one logical binary action such as incrementing a binary field by one. In fact, microprocessors often come with several instruction sets for specific purposes. For example, the Intel Pentium processor not only contains the x86 instruction set, but also introduced the MMX instruction set, which added additional instructions and logical binary actions to assist in the manipulation of multimedia processing. These instruction sets define a processor's capabilities and often are a good measure of any microprocessor's true processing performance.
  
  

Registers

• Registers are small on-die memory locations built into the microprocessor, which are utilized to store binary data and the currently executing instruction to apply to that data. The size of a register's memory capacity is dictated by the overall architecture of the microprocessor. For example, a 16-bit microprocessor would have a register AX and BX, whereas a 32-bit processor would have a register called EAX and EBX. The E signifies that the register has been extended to encompass a 32-bit field as opposed to the 16-bit field available to the standard 16-bit register. Registers are the direct working memory of a microprocessor itself and all input and output data goes through these registers directly before and after instruction execution has occurred.
  
  

Data Flow and Cache Memory

• Cache memory is the immediately available memory between all other hardware in a computer and the microprocessor itself. Cache memory is the first step in the data processing procedure. This is where instructions and requests from all other hardware within a computer are initially presented to the microprocessor. The microprocessor then utilizes a processing engine such as the out-of-order core to dictate that instruction needs to be applied in what order to allow for coherent and efficient processing. It is also during this time in cache memory that a microprocessor, if designed with such circuitry, will utilize a predication engine in an attempt to save processing cycles by simply repeating instructions that are already in the cache as opposed to re-requesting them from the computer's main memory. The data and instructions are moved from the cache memory into registers to be taken to the execution engine which will apply the binary instructions to its associated data and output the results back into the cache memory. Once this is accomplished, the information is then sent to the appropriate requesting device which sent the original microprocessor interrupt and data to the on-die cache memory.