Microprocessor

A microprocessor is a programmable electronics chips that has computing and decision making capabilities to similar to central processing unit of computer.
                            The microprocessor is a semiconductor manufactured by VSLI  (Very Large Scale Integration) technique.It includes arrays,register, control circuits on single chip.

             To perform a function or useful task we have to form a system by using microprocessor as a CPU  and interfacing memory, input and output devices to it. A system designed using a microprocessor as its CPU (Central Processing Unit) is called a microcomputer.
                    When your computer is turned on, the microprocessor first gets instuctions  from Basic input/output that comes with the computer as a part of its memory.
  

Structure

Internal structure of microprocessor depends on age of the design and the intended purpose of the microprocessor according to how it is useful.

      The complexity of integrated circuit (IC) is bounded by physical limitaions of  number of  transistors that can be put in one chip.

        If the complexity of circuit is more then coding will be easier here internal circuit need not to be handle by user. The users only need to know some basic about programming.

         
Occasionally, physical limitations of integrated circuits made such practices as a bit slice approach necessary. Instead of processing all of a long word on one integrated circuit, multiple circuits in parallel processed subsets of each data word. While this required extra logic to handle, for example, carry and overflow within each slice, the result was a system that could handle, for example, 32-bit words using integrated circuits with a capacity for only four bits each.

Special-purpose designs

 

A microprocessor is a general purpose system. Several specialized processing devices have followed from the technology:

• A digital signal processor (DSP) is specialized for signal processing.
• Graphics processing units (GPUs) are processors designed primarily for realtime rendering of 3D images. They may be fixed function (as was more common in the 1990s), or support programmable shaders. With the continuing rise of GPGPU, GPUs are evolving into increasingly general purpose stream processors (running compute shaders), whilst retaining hardware assist for rasterizing, but still differ from CPUs in that they are optimized for throughput over latency, and are not suitable for running application or OS code.
• Other specialized units exist for video processing and machine vision.
• Microcontrollers integrate a microprocessor with peripheral devices in embedded systems. These tend to have different tradeoffs compared to CPUs.

• Market statistics

  In 1997, about 55% of all CPUs sold in the world are 8-bit microcontrollers, over two billion of which were sold.
  In 2002, less than 10% of all the CPUs sold in the world were 32-bit or more. Of all the 32-bit CPUs sold, about 2% are used in desktop or laptop personal computers.
   Most microprocessors are used in embedded control applications such as household appliances, automobiles, and computer peripherals.
   Taken as a whole, the average price for a microprocessor, microcontroller, or DSP is just over US$6 (equivalent to $8.16 in 2017).
  In 2003, about US$44 (equivalent to $58.53 in 2017) billion worth of microprocessors were manufactured and sold. Although about half of that money was spent on CPUs used in desktop or laptop personal computers, those count for only about 2% of all CPUs sold.
   The quality-adjusted price of laptop microprocessors improved −25% to −35% per year in 2004–2010, and the rate of improvement slowed to −15% to −25% per year in 2010–2013.
                                               About ten billion CPUs were manufactured in 2008. Most new CPUs produced each year are embedded.