Post on 28-Dec-2015
transcript
External Data Bus
Make sure that you read the analogy explaining exactly what the external data bus isbinary system - a numbering system using 0’s and 1’s onlyBinary numbering will be in groups of 8 because 8 bits make a byte How do you read bits, and change binary to
decimals?
Registers / Clocks
Registers Used as a workplace for problems that you
give the PC
Clocks the maximum number of clock cycles that
your CPU can handle is called the clock speed
a CPU’s clock speed is its maximum speed, not the speed that it will always run at
the system crystal determines the speed at which the CPU will operate
Clocks
The system crystal is a quartz oscillator that is soldered into the motherboard
A CPU can be pushed by a crystal with a lower clock speed that its own, but the CPU will operate at the speed of the crystal
Don’t try to run a CPU faster than its clock speed, or it will overheat and lock up
Underclocking - run a CPU slower that its CS Overclocking - run a CPU faster than its CS
RAM as a spreadsheet
The CPU needs a place to store data, that’s where RAM comes into placeQuick Terminology Chart Any individual 1 or 0 = a bit 4 bits = a nibble 8 bits = a byte 16 bits = a word 32 bits = a double word 64 bits = a paragraph
MCC / Address Bus
Memory Controller Chip (MCC) device that facilitates the flow of data
from RAM to the CPU
Address Bus second set of wires that enables the
CPU to communicate with the MCC
MCC - grabs contents of RAMAddress Bus - controls what it gets
CPU packages
Dual Inline Pin Package (DIPP)Pin Grid Array (PGA) (ZIF)Staggered Pin Grid Array (SPGA)Plastic/Ceramic Quad Flat Pack (PQFP) Used on laptops
Plastic/Ceramic Leaderless Chip CarrierSingle Edge Contact Cartridge (SECC)Plastic Pin Grid Array (PPGA)
Voltage Regulators
Can convert one voltage of electricity into a lower oneAre near a fan because they generate a good deal of heatThanks to laptops we use these in PCsNecessary to reduce CPU to 3.3 vVoltage set by jumper settingAPM also was developed around this time
Cache
Cache - set aside data used in the past in a special, fast storage area enables you to speed up the system
by creating special storage areas for data being moved form the hard rive, RAM, and CPU
Dynamic RAM (DRAM)
RAM of choice in the PC world cheap, small, and relatively fast
Hold capacitors, like batteries, that hold small charges, need to be refreshed considered volatile RAM not as fast as the CPU
Static RAM (SRAM)
SRAM helps get rid of wait states uses a special circuit called a flip-flop,
which gets rid of refresh almost as fast as the fastest CPU very expensive, but doesn’t need to
be refreshed, so uses less effort, PC more efficient
Internal/External Cache
Internal cache small SRAM Cache built in to chip called L1 cache
External cache called L2 cache soldered onto the motherboard in old PC’s mostly integrated into chips since Pentium II
Clock doubling
Running the internals of a CPU at one clock speed, and running the external data bus and address bus at another slower, speed to help CPU makers increase clock
speeds without having to change the motherboards
Pentium
Intel introduced the Pentium processor in 1993 had a 64-bit external data bus that split
internally as 2 dual pipelined 32-bit data buses
dual pipelining - second set of circuitry that enables more than one command to be processed at a time
Pentium
The first 2 Pentium CPU’s, the 60 MHz and 66MHz, needed 5 volts for operation ran very hot
Used clock doubling because motherboards that couldn’t keep up with speedJumper used to set multiplier
Pentium and competitors
The text discusses several different competitors as well as Pentium II & III. You should know why each one was introduced and different cache sizes, speeds, and clock doubling. Take time to read through these.
Celeron
Intel-based CPULow-end (cheap)SEP (like SEC, but no plastic side)Added 128K cacheProblems SEC was proprietary Only ran at 66Mhz, with multiplier
Celeron II Same thing, only in PGA form
Pentium II
SEC cartridgeFit into “Slot 1” (Intel)Used MMX technology 57 new commands in instruction set Four new registers
AMD countered with K6 Could support 100 Mhz motherboards Could not fit into Slot 1, so
motherboards had to be created for it
Athlon
AMD’s answer to the Pentium IIProprietary to AMD, SEC-typeFaster than Celeron (100 Mhz vs 66)Could run 2 calculations per cycle, so effectively ran at 200-266 Mhz
Pentium III
Supports 100/133 Mhz motherboardsHigh-speed L2 cacheFirst came in SEC, then in PGA type Less space, cheaper to make
Pentium 4
Takes 100 Mhz motherboard and allows four data transfers per cycle, total of 400 Mhz bus (double of Athlon)