chapter_6_THE_SYSTEM_UNIT.pptVIP

* Located on the microprocessor chip and has two components - the control unit and the arithmetic and logic unit RISC and CISC are two types of microprocessors. Control Unit Program instructions Directs flow between memory and ALU Directs flow between CPU and I/O devices Arithmetic-Logic Unit - ALU Two types of operations Arithmetic Logical Microprocessor Chips Word size CISC RISC Smart Card * A word is the number of bits that can be accessed at one time by the CPU Older computers process data and instructions in millionths of a csecond – microseconds Newer computers Nanoseconds – microcomputers Picoseconds – supercomputers Types of chips CISC – Intel’s Pentium processors use this chip RISC – used in powerful workstations * Specialty processors are designed to handle special functions Graphics Displaying and manipulating 2-D and 3-D graphics images Parallel Runs large programs Approach is called parallel processing Smart cards Plastic cards that have an embedded chip Can store 80 times the information stored on the magnetic strip pf a regular credit card * RAM Frequently accessed Acts as high-speed, temporary holding area Faster processing results Temporarily holds data and programs being processed by the CPU Volatile - when power shuts off, contents of RAM are emptied Exception - flash RAM can retain data when power disrupted, used in high end portable computers Cache Pronounced: “cash” Area in RAM set aside to store information frequently accessed Acts as a high-speed, temporary holding area for parts of programs and data Results in faster processing results for the user ROM – Read Only Memory; nonvolatile; CPU retrieves programs written on the ROM chip. Typical user does not go in and change information on ROM Also called firmware. CMOS – complementary metal-oxide semiconductor provides flexibility and expandability for system * Memory is the holding area for data, instructions, and information Contained on chips connected to the system board The thre