Parts of Processor

Registers

When the processor executes instructions, knowledge is temporarily stored in little, local memory locations of 8, 16, 32 or 64 bits called registers. Depending on the type of processor, the general number of registers can vary from about0 to plenty of hundreds.

- The main registers are:

1.the accumulator register (ACC), which stores the results of arithmetic & logical operations;

the status register (PSW, Processor Status Word), which holds technique status indicators (carryover digits, overflow, etc.);

2.the instruction register (RI), which contains the current instruction being processed;

the ordinal counter (OC or PC for Program Counter), which contains the address of the next instruction to process;

3.the buffer register, which temporarily stores knowledge from the memory.

Cache Memory

     Cache memory (also called buffer memory) is local memory that reduces waiting times for information stored in the RAM (Random Access Memory). In effect, the computer's main memory is slower than that of the processor. There's, however, types of memory that are much faster, but which have a greatly increased cost. The solution is therefore to include this type of local memory close to the processor & to temporarily store the primary information to be processed in it. Recent model computers have lots of different levels of cache memory:

- Level cache memory (called L1 Cache, for Level one Cache) is directly integrated in to the processor. It is subdivided in to parts:

1. the first part is the instruction cache, which contains instructions from the RAM that have been decoded as they came across the pipelines.

2. the second part is the information cache, which contains information from the RAM & information recently used in the coursework of processor operations.

Level one caches can be accessed quickly. Access waiting time approaches that of internal processor registers.

-Level cache memory (called L2 Cache, for Level two Cache) is located in the case along with the processor (in the chip). The level cache is an intermediary between the processor, with its internal cache, & the RAM. It can be accessed more quickly than the RAM, but less quickly than the level cache.

-Level cache memory (called L3 Cache, for Level seven Cache) is located on the motherboard.

All these levels of cache reduce the latency time of various memory types when processing or transferring information. While the processor works, the level cache controller can interface with the level controller to transfer information without impeding the processor. As well, the level cache interfaces with the RAM (level cache) to permit transfers without impeding normal processor operation.

Control Signals

    Control signals are electronic signals that orchestrate the various processor units participating in the execution of an instruction. Control signals are sent using an element called a sequencer. For example, the Read / Write signal allows the memory to be told that the processor desires to read or write information.

Clock

    Another part that is included in parts of the computer CPU is the clock. The clock is made of timing circuitry that measures the timing of tasks performed by the CPU in terms of clock cycles. The performance of processors is usually measured by the clock rate or clock speed of the CPU. In theory, a higher clock speed means that the CPU can execute instructions (cycles) faster. The clock speed is measured in "hertz." Hertz refers to the quantity of clock cycles per second. A CPU with a speed of one GHz would mean that it performs billion clock cycles per second.

ALU

    The arithmetic logic unit (ALU) is of the most important parts of the computer's CPU. It is comprised of electronic circuits that make it able to executing arithmetic and logic operations. It works with different registers to store knowledge or hold knowledge about the latest action performed by the logic unit. The ALU has the ability to perform types of arithmetic operations: addition, subtraction multiplication and division.

    The ALU also has the means to perform kinds of logic comparisons: equal-to, less-than and greater-than. The ALU can comparing letters, numbers or special characters. The personal computer then takes action based on the results of the comparison. An example of such a comparison would be the following "less-than" operation: If the average check score of a student is less than 70 percent, then the student receives a "fail" grade; otherwise, the grade is "pass."