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1.1 Systems Architecture - Coggle Diagram
1.1 Systems Architecture
1.1.2 CPU Performance
Cores
Modern CPU's are divided into "cores"
Multiple Cores means that a number of tasks can be carried out simultaneously
2 core = Dual cores 4 core = Quad cores
More cores does not means quicker CPUs
Clock
Clock speed is measured in Hertz(Hz)
1 clock tick is a single Hertz
Most CPU's can do about 3 billion instructions per second.(3GHz)
A CPU can be "overclocked" to run faster but that takes even more cooling down
Cache
Very small but fast type of memory
TEMPORARY STOREGE BETWEEN THE CPU AND RAM. - STORES FREQUENTLY USED DATA AND INSTRUCTIONS(CAN BE BOTH EXTERNAL AND INTERNAL)
A CPU ALWAYS HAS AN INTERNAL CACHE
1.1.1 Architecture of the CPU
1.1.1a The Purpose of the CPU & Fetch-Execute cycle
Fetch-Decode-Execute Cycle
Decode: Looks at the instruction and works out what to do with it.
Execute: Carry out the instruction.
Fetch: An instruction is fetched from memory and brought to the CPU for processing
The Purpose of the CPU
The CPU(Central Processing Unit) is commonly referred to as the "BRAIN" of the computer. It is responsible for executing a sequence of stored instructions called a program.
1.1.1c Von Neumann Architecture
1.1.1b Common CPU components and their functions
Cache
The Cache is a type of temporary memory
•IT IS FASTER TO ACCESS THAN RAM, BUT SLOWER TO ACCESS THAN THE REGISTERS
•THERE CAN BE BOTH AN INTERNAL CACHE (INSIDE THE CPU) AND AN EXTERNAL CACHE (OUTSIDE THE CPU)
Clock
The clock is a tiny quartz crystal inside the CPU which ticks at a steady speed
•EACH TIME THE CLOCK TICKS THE CPU CAN PROCESS ONE INSTRUCTION
ALU(Arithmetic Logic Unit)
The ALU handles data processing inside the CPU
•IT PERFORMS STANDARD ARITHMETIC OPERATIONS SUCH AS ADDITION, SUBTRACTION ETC
•IT DEALS WITH LOGIC AND COMPARISONS SUCH AS ‘IS THIS VALUE GREATER THAN THAT VALUE?’
Buses
Tracks on a circuit
ADDRESS BUSES TO CARRY LOCATIONS
CONTROL BUSES CONTROL DEVICES
DATA BUSES TOE CARRY DATA
CU(Control Unit)
The CU performs 3 tasks:
•IT CONTROLS THE WAY DATA MOVES AROUND THE CPU
•IT CONTROLS AND MONITORS THE FLOW OF DATA BETWEEN THE CPU AND OTHER HARDWARE COMPONENTS
•IT EXECUTES THE INSTRUCTIONS PROVIDED BY THE PROGRAM
1.1.3 Embedded Systems
