Transcript ppt - AD Book Enterprises

9/21 The CPU
• CPU terms
– capacity, -bit
– clock speed, MHz
– CISC, RISC
• CPU brands & models
image courtesy of AMD.com
CPU: Central Processing Unit
• The Microprocessor or
CPU (Central Processing
Unit) is the “brains” of
the computer.
• All other components
(RAM, monitor, disk
drive) act like bridges to
link you & the processor.
image courtesy of AMD.com
CPU: Central Processing Unit
• The Microprocessor or
CPU (Central Processing
Unit) is the “brains” of
the computer.
• All other components
(RAM, monitor, disk
drive) act like bridges to
link you & the processor.
image courtesy of How Computers Work
Standard Pentium Parts
8K Code Cache
BIU
Bus
Interface
Unit
Branch
Predictor
Unit
Instruction
Prefetch Buffer
& Decode Unit
ALU ALU
Registers
To RAM
8K Data Cache
Floating
Point
Unit
Pentium Parts
Branch
Predictor
The BIU sorts
Unitthrough
Instructionthe data and code that is
Prefetch Buffer
sent from RAM. The
& Decode Unit
8K Code Cache
BIU
Bus
Interface
Unit
To RAM
code is sent one way, and
the data is sent the other
ALU ALU
way. After
the processing,
Floating
Pointsend the
the BIU will
RegistersprocessedUnit
data back to
RAM.
8K Data Cache
Pentium Parts
8K Code Cache
BIU
Bus
Interface
Unit
Branch
Predictor
Unit
Instruction
Prefetch Buffer
& The
Decode
Unit one for data and one
caches,
for code, are the “ready rooms”
for the ALU’s.
ALU ALU
Registers
To RAM
8K Data Cache
Floating
Point
Unit
Pentium Parts
8K Code Cache
The Branch Predictor
Instruction
Unit decides which ALU
Prefetch Buffer
& Decode Unit
will be quicker
BIUat
processing the
next
Bus
instruction.Interface
Unit
ALU ALU
Registers
To RAM
8K Data Cache
Branch
Predictor
Unit
Floating
Point
Unit
Pentium Parts
The Instruction
Prefetch Buffer
retrieves the BPUspecified code from
the cache. The
BIU
Decode Unit Bus
converts theInterface
code
Unit
into ALU-usable
instructions.
8K Code Cache
Branch
Predictor
Unit
Instruction
Prefetch Buffer
& Decode Unit
ALU ALU
Registers
To RAM
8K Data Cache
Floating
Point
Unit
Pentium Parts
The Floating Point Unit8K Code Cache
processes the numbers
after the decimal point, Instruction
Prefetch Buffer
as well as other
& Decode Unit
BIU
specified commands.
Bus
Interface
Unit
ALU ALU
Registers
To RAM
8K Data Cache
Branch
Predictor
Unit
Floating
Point
Unit
Pentium Parts
The Arithmetic Logic
Units process the
data using specially
wired circuits and
transistors. Their
output is sent toBIU
the
registers, a kindBus
of
Interface
“electronic scratch
Unit
pad.”
8K Code Cache
Branch
Predictor
Unit
Instruction
Prefetch Buffer
& Decode Unit
ALU ALU
Registers
To RAM
8K Data Cache
Floating
Point
Unit
Pentium Parts
BIU
Bus
Interface
Unit
Branch
The Data Cache
transfers
8K Code Cache
Predictor
the processed information
Unit
from the registers back to
Instruction
Prefetch Buffer
the BIU, which sends it to
& Decode Unit
the RAM.
ALU ALU
Registers
To RAM
8K Data Cache
Floating
Point
Unit
Pentium Parts
8K Code Cache
BIU
Bus
Interface
Unit
Branch
Predictor
Unit
Instruction
Prefetch Buffer
& Decode Unit
ALU ALU
Registers
To RAM
8K Data Cache
Floating
Point
Unit
Coprocessors
• Coprocessors are also
in PC’s.
• They handle functions
like graphics, 3-D
acceleration, and sound
cards.
• Help reduce the load on
the main processor.
image courtesy of How Computers Work
Data Capacity
• refers to the amount of data that the processor can
process at one time. If a number is bigger than what the
processor can handle, it breaks it down into manageable parts,
processes it, and puts it back together.
• 8 bit processor: handles
numbers up to 8 bits long
(2 to the 8th power: 256)
• 16 bit processors handle
numbers up to 2 to the
16th power or 65,536)
• 32, 64 bit processing (etc.)
Clock Speed
• Timer that everything in the processor uses as a
pacesetter.
• Measured in MegaHertz ( millions of cycles per
second)
• Same model of processors can have their
clock speeds compared.
• Different models of processors
cannot be compared so easily.
image from http://web.scps.k12.fl.us/site/agenda/default.htm
Instruction Sets
!
• A chip’s vocabulary.
• Types of instructions that a chip can perform.
• Bigger does not necessarily equal better in
instruction sets.
• CISC: Complex instruction set chips
– use complex instructions to process instructions.
• RISC: Reduced instruction set chips
– break down instructions before processing with a
simpler instruction set.
Types of chips: Intel
• Intel Pentium III - specs
– up to 1.13 GHz
– 70 new instructions for 3D, voice recognition, etc.
– integrated 512 KB L2 cache
• Intel Celeron - specs
– economy chip
– up to 700 MHz
– integrated 128 KB L2 cache
images courtesy of Intel
Types of chips: AMD
• AMD Athlon - specs
– up to 1.1 GHz
– integrated 256 KB L2 cache
– 200 MHz system bus
• AMD Duron – specs
– economical
– up to 750 MHz
– 128 KB L1 cache, 64 KB L2 cache
images courtesy of AMD
Types of Chips: Other Brands
•
•
•
•
•
Cyrix MII
Motorola PowerPC
Apple
Sun
Digital
• others available
images courtesy of Sun