Goal 1.2 Computer System Flashcards
Processor:
CPU (Central Processing Unit):
“Brains” of the computer
Executes ______
Fetch instruction from memory
Examine
Execute one after the other
Data transferred between components on a ____
programs
bus
Processors:
Components of CPU
ALU
Registers
- High speed
- Holds one number of some bits
- Usually same size, but some have specialized functions
- Program Counter
- Instruction Register
Control Unit
Data Path consists of:
Registers
ALU
- Mathematical operations
- Boolean operations
ALU Input Registers
ALU output register
Instruction type:
Register-Memory
Data fetched from memory to _____
Data ______ in memory from register
register
stored
Instruction type:
Register-Register
Data fetched from 2 registers
Manipulated in _____
Stored back in another/same _______
Data path cycle
Multiple ALU’s
ALU
register
Instruction Execution
- Fetch the next ______ from memory into the instruction register
- Change the program ______ to point to the next instruction
- Determine the type of instruction just fetched
- If instruction uses a word in memory, determine where it is
- Fetch the _____, if needed, into a CPU register
- Execute the instruction
- Return to step __
instruction
counter
word
1
RISC
Reduced Instruction Set Computer
Around 50 instructions
Each does less, but executes much ____.
Hardware implementation with no translation
Phones, IOT, things not worried about ____ ______.
Lower power consumption
faster
backwards compatibility
CISC
Complex Instruction Set Computer
______ of instructions
Each instruction slower to execute, but does more
___/____ ____ computers
- Have RISC core as compromise
Backwards compatibility keeps it alive
Hundreds
Intel/AMD x86
Design Principles for Modern Computers
All instructions directly executed by _____
Maximize rate at which instructions are issued
Instructions should be easy to ____
Only loads and stores should _____ memory
Provided plenty of ______
hardware
decode
reference
registers
Pipelining
Allows for multiple instructions to be executed at once.
Longer pipelines
allow for smaller chunks
more instructions being executed
Higher Mhz/Ghz
May have to clear pipeline more often
smaller pipelines
bigger chunks
lower Mhz/Ghz
Can be more efficient
Primary Memory
Stores programs and data
Stored in 1’s and 0’s (bit)
uses ____/_____ to store multiple bits assigned to one address
Each cell has the same number of ____
cells/locations
bits
Less bits/cell ⇒ more memory addresses ⇒
larger instructions
more bits/cell ⇒ less memory addresses ⇒ smaller instructions ⇒
Wasted memory
32bit computer ⇒ 232 memory addresses ⇒
4,294,967,296 bytes of memory.
frequently used data is stored in ______
cache
Memory hierarchy/ Memory pyramid:
Registers
____
Main Memory
Magnetic or solid state disk
___/____ disk
Cache
Tape/ Optical
the most important component of a computer system. A control unit is a part of the CPU.
Central processing unit
controls the operations of all parts of the computer but it does not carry out any data processing operations.
control unit
directs the operation of the processor. It was included as part of the Von Neumann Architecture
control unit
It is the responsibility of the control unit to tell the ____ _____, arithmetic/logic unit, and input and output devices how to respond to the instructions that have been sent to the processor
computer’s memory
It is the responsibility of the control unit to tell the computer’s memory, arithmetic/logic unit, and input and output devices how to respond to the instructions that have been sent to the processor.
It fetches ______ instructions of the programs from the main memory to the processor instruction register, and based on this register contents, the control unit generates a ____ _____ that supervises the execution of these instructions.
internal
control signal
A control unit works by receiving input information which it converts into ____ _____, which are then sent to the central processor. The computer’s processor then tells the attached hardware what operations to perform. The functions that a control unit performs are ______ on the type of CPU because the architecture of the CPU varies from manufacturer to manufacturer.
control signals
dependent
devices that require a CU (Control Unit) are:
Control Processing Units(CPUs)
Graphics Processing Units(GPUs)
Functions of the control unit:
It coordinates the sequence of data movements into, out of, and between a processor’s many ____.
It interprets _____.
It controls data flow inside the processor.
sub-units
instructions
Functions of the control unit:
It receives _____ instructions or commands to which it converts to sequence of control signals.
It controls many _______ units(i.e. ALU, data buffers and registers) contained within a CPU.
It also handles multiple tasks, such as _____, decoding, execution handling and storing results.
external
execution
fetching
There are two types of control units:
Hardwired
Micro programmable control unit.
