CPU/BIOS/BUS CES Industries, Inc. Lesson 8

 Brain of the computer  It is a “Logical Child, that is brain dead”  It can only run programs, and follow instructions contained in the program.  The operating system controls the flow of information to and from the processor and the application.  Most modern processors are 32 bits which allow information to be processed in groups of 32 bits or binary digits at one time and in one clock cycle. CPU CES Industries, Inc.

 Contains millions of transistors and is able to perform mathematical calculations, evaluate logical instructions and control program flow. The CPU CES Industries, Inc.

 Normally contains 6 internal sections 1. Arithmetic Logic Unit 2. Program Counter 3. Internal Registers 4. Control Logic 5. Instruction Decoder 6. Bus Interface Logic The CPU CES Industries, Inc.

 Two arithmetic logic units  Two internal caches for data and instructions.  Specialized floating point unit for decimal math.  A Branch Prediction Unit (BPU) to logically “guess” what the next instruction will be if the instruction is a “yes/no” type of question.  The Pentium 4, operating a 2.2 GHz, is able to add a column of numbers, 2 billion numbers long, in ONE SECOND! The Pentium adds: CES Industries, Inc.

 IC chip called EPROM (Erasable Programmable Read Only Memory).  Modern computers use Flash ROM’s that allow for field programming of the BIOS, whenever an upgrade is required.  CMOS Memory- stores information about all the hardware installed in your computer.  Startup instructions that transform RAM and ROM into a fully functional computer.  Contains the POST program, to perform power on diagnostics  Contains the “Setup” program to allow you to customize the “list of contents” contained within the computer. BIOS CES Industries, Inc.

 Is simply a collection of wires, organized by their function.  The data bus, moves information.  The address bus, identifies where something is stored  The control bus, controls the movement of data. BUSES CES Industries, Inc.

BUS  Industry Standard Architecture (ISA) - original PC connector; 8 or 16 bit data transfer; 7.59 MHz.  Enhanced Industry Standard Architecture (EISA) - enhancement of ISA; 32 bit data transfer, bus mastering.

 VLB or local bus - extension slot added to ISA to allow for 32-bit data transfer up to 33 MHz. Used with 386 and 486 boards. This bus has disappeared.  Peripheral component interconnect (PCI) - latest standard; 64 bit data transfer; Up to system speed. Supports burst mode - speeds approaching 500 MHz. Developed by Intel and used on all Pentiums.  CNR: Communications and Network Riser, provides support for integrated high speed modems, network cards and sound systems BUS CES Industries, Inc.