1.1 System Architecture Flashcards
Program Counter(PC)
Holds the address of the next instruction
MAR(Memory Address Register)
Holds the address of the data/instruction to be fetched from the RAM
MDR(Memory Data Register)
Holds the data/instruction fetched from the RAM
ACC(Accumulator)
Holds the result of the calculation/operation done by the ALU
CIR(Current Instruction Register)
Holds the current instruction being executed
CU(Control Unit)
Handles movement of instructions and data around the computer, fetches, decodes, executes instructions, control signals that control hardware
Why use Von Neumann Architecture?
Uses a stored program concept, stores the program instructions which are stored in the same place as the data which is used when running a program. Don’t have to run a program separate to data making it easier to set up and run system
What holds the data/instruction fetched from RAM?
MDR(Memory Data Register)
What holds the current instruction being executed?
CIR(Current Instruction Register)
What holds the result of the calculation/operation done by the ALU?
ACC(Accumulator)
What holds the address of the next instruction?
PC(Program Counter)
What holds the address of the data/instruction about to be fetched from the RAM?
MAR(Memory Address Register)
What 5 components are registers?
PC, MAR, MDR, ACC, CIR
CPU:
Fetch, decode and execute instructions
Fetch-Execute Cycle:
Fetches the next instruction from RAM, works out what to do with it, carries it out, increments PC by 1
Cache:
Very fast memory in CPU, slower than registers, faster than RAM. Stores frequently used data that the CPU can access quickly. Greater storage than registers.
Clock speed:
The number of instructions a single processor core can execute per second
Cache size:
A larger CPU cache gives the CPU faster access to frequently used instructions without having to fetch these instructions from RAM. Improves performance
Number of cores:
Each CPU core can process data independently. The more cores a CPU has the more instructions it can carry out at once
Embedded systems:
Computers built into other devices. Dedicated systems so easier to design and produce
ALU
Performs mathematical and logic operations, gateway between primary and secondary storage
Registers:
Small amounts of high speed memory in CPU, store data needed for processing
Difference between data and address:
Address: unique identifiers to locations in memory for the data - information
Embedded systems:
Specific function, dishwashers, digital watches, electronic calculators, less processing power and power, cheap to design
