Introduction

   The predominant form of microprocessor has been from Intel Corp through most of the history of personal computers. The first processor in an IBM PC was Intel’s 8088. The generations of Intel processors that followed it were in the 80X86 family the 8086, 80826, 80836 and 80846. The 8088 for example, operated at 4.7MHz(million frequency waves a second)—and some 80846chips go as fast as 133MHz. The 8088 could handle 8 bits of data at a time, and the 80486 handles 32 bits internally.

CPU (Central processing unit)

  • CPU controls all operations

  1. Reading of input from an input device

  2. Processing of input device

  3. Writing of output using an output device 

 

  • CPU consists mainly of

  1. ALU (Arithmetic & logic unit)

  2. Control unit

  3. Internal Memory

  • How CPU executes a normal instruction

  1. an instruction is brought from main memory to the control unit and analyzed

  2. the control unit sends the necessary data to the ALU and the instruction is carried out

  3. the results of the operation are stored in main memory