66 CHAPTER SYSTEM UNIT

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-2 Lecture Objectives System unit components Microprocessors Memory Microprocessor Details Microprocessor Components Main Types (CISC/ RISC) of Microprocessors Word Size of a Microprocessor

System Board Allows I/O devices to communicate with the system unit.

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-4 System Board Connects all components Allows communication between devices Main board or motherboard Circuit board electronic components Sockets Slots Bus lines

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-5 Microprocessor Central Processing Unit (CPU ) Two basic components Control unit Arithmetic and logic unit

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-6 The Microprocessor chip Control Unit sends control signals to the rest of the devices like Memory – reading/writing for instructions/data/results Arithmetic Logic Unit Other external devices – for input/output etc. ALU performs arithmetic or logical operations

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-7 … The Microprocessor chip Input Devices Output Devices MouseKeyboard PrinterScreen ProgramProblem Data Control Unit ALU

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-8 Microprocessor Chips Chip capacities are expressed in word sizes Types of microprocessor chips CISC chips: Complex instruction chips Most widely used design Used by Intel RISC chips: Reduced instruction set computer chips Uses fewer instructions Design is simpler and less costly Used by the PowerPC

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-9 Microprocessor & Small Server Chips CISC Examples Pentium III and Pentium IV are most recent forms Intel, AMD and Cyrix III are popular vendors of CISC type RISC Examples Motorola’s PowerPC Compaq's Alpha Silicon Graphics' MIPS

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Microprocessor & Server Chips

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Microprocessor Chips Word size Number of processed bits Expresses chip capacity Size of word determines power 32 bit processor– 4 bytes at a time 64 bit processor – 8 bytes at a time

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Specialty Processors Graphics coprocessors Parallel processors Smart cards

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved More Microprocessor Detail on the Web

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved Technology Description from Intel Executives Commentary by WILLIAM A. SWOPE, President Intel Architecture Group [video clip] Commentary by MICHAEL J. FISTER, Vice President and General Manager, Enterprise Platforms Group [ Video clip]

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved. 1-15